According to a scientific review published in the journal Foods, extra virgin olive oil may modulate and enhance the vast bacterial, viral, fungal, and archaeal populations inhabiting the human gut, known as the microbiota.

These microorganisms and functional cells are essential for metabolizing nutrients, drugs, and toxins, as well as for synthesizing many vitamins.

The microbiota also stimulates and supports the immune system, strengthening the intestinal barrier and modulating allergies, bowel diseases, metabolic syndrome, and neurodegenerative conditions.

A healthy microbiota is associated with lower risks of cardiovascular disease, cancer, obesity, diabetes and other conditions. It also impacts mood, stress response and mental health.

Researchers reviewed how olive-derived bioactive compounds promote intestinal health while modulating gut activity.

More specifically, they focused on the impact of polyphenols, secoiridoids and triterpenes on the human gut.

Although they make up less than two percent of extra virgin olive oil, these compounds can reduce inflammation and combat oxidative stress.

They help protect blood vessels, regulate metabolism and influence brain and immune function.

The review took into consideration hundreds of existing studies from a vast array of in vitro (laboratory-based), in vivo (animal studies) and human clinical trials.

The review confirmed that polyphenols, secoiridoids and triterpenes boost beneficial bacteria populations, notably Lactobacillus and Bifidobacterium.

These microbes are essential for maintaining gut balance, producing beneficial metabolites and supporting overall gut health.

The review also showed that these substances suppress potentially pathogenic bacteria, contributing to a more balanced and resilient microbial ecosystem.

One of the most critical effects highlighted by the review is the role of polyphenols, secoiridoids, and triterpenes in stimulating the production of SCFAs, which are fatty acids produced when gut bacteria break down dietary fiber and certain polyphenols in the colon.

These fatty acids are vital for nourishing the cells lining the colon, maintaining the integrity of the intestinal barrier and reducing inflammation within the gut.

According to the researchers, these olive compounds have been shown to contribute to a more robust intestinal barrier.

This “protective shield” is considered key to preventing the leakage of harmful substances from the gut into the bloodstream, which can trigger systemic inflammation and various health issues.

The review also noted evidence from the current literature of how these olive bioactive substances can alleviate metabolic, inflammatory and neurocognitive disorders.

This wider influence is attributed mainly to their modulation of the gut-microbiota-brain axis, where gut microbes produce compounds that interact with the central nervous system.

The authors also noted some limitations due to inherent challenges in gut microbiome research. 

These challenges include the vast interindividual variability in gut microbiota composition.

In addition, they noted the current lack of standardized intervention protocols across studies and the relatively limited number of human clinical trials compared to those involving animals.

In their opinion, the potential demonstrated by these substances highlights the need for more robust research to bridge findings from animal models to human physiology effectively.

The authors emphasized that future human studies must consider key individual differences, including age, diet, genetics, health status, and gut microbiota composition. 

The researchers indicated that these differences can influence how people respond to olive bioactives. If ignored, they could lead to unreliable results.

The authors noted that by carefully controlling or tracking these “host variables,” researchers can enhance the quality, accuracy, and reproducibility of their findings, thereby ensuring that the observed effects are genuinely due to the compounds studied, rather than underlying personal or biological differences.

“Translating these insights into dietary recommendations and functional products will require multidisciplinary, integrative studies that combine clinical trials with advanced multi-omics and systems biology approaches,” the authors wrote.

Multi-omics refers to the integrated study of multiple biological layers, like genes (genomics), proteins (proteomics), metabolites (metabolomics) and microbes (microbiomics).

“By deepening our mechanistic understanding and standardizing olive oil compositions, we could fully unlock the therapeutic potential of olive bioactives for metabolic, inflammatory and gut-brain axis-related disorders,” the researchers concluded.

Initial research shows that the antioxidant, anti-inflammatory and potential anti-atherosclerotic properties of this phenolic compound may significantly impact human health.

Most health-conscious consumers are familiar with antioxidants, including hydroxytyrosol or flavonoids, due to decades of research on the compounds.

Due to its unique nature, research on oleacein began relatively recently. It was initially discovered and isolated in olive leaves, and its role in extra virgin olive oil was not immediately evident.

According to the researchers studying this molecule, oleacein is both one of the most abundant phenolics in virgin olive oils and one of the most chemically active.

Where does oleacein come from?

Oleacein is found almost exclusively in high-quality, fresh extra-virgin olive oil and results from transformations that occur during olive processing.

“Oleacein originates from the hydrolysis of the glycoside oleuropein,” Maria de Fátima Paiva-Martins, researcher at the University of Porto’s chemistry and biochemistry department, in Portugal, told Olive Oil Times.

Hydrolysis is a chemical reaction in which complex substances, such as proteins or fats, are split into simpler ones.

During the olive crushing process, oleuropein undergoes enzymatic hydrolysis, which produces aglycone, a more fat-soluble molecule. “This aglycone then transforms into oleacein,” Fátima Paiva-Martins said.

Where hydroxytyrosol and oleacein meet

One of the most interesting components of extra virgin olive oil, hydroxytyrosol, is not present in high amounts in olive oil.

Instead, it is a metabolite, a byproduct that appears in the human body after ingesting compounds, including oleacein.

“Hydroxytyrosol is highly hydrophilic, so it doesn’t remain in the olive oil. What we find in higher concentrations are its esters, like oleacein, which later hydrolyze into hydroxytyrosol after digestion,” Fátima Paiva-Martins said.

Extra virgin olive oil’s phenol esters are compounds formed when a phenol (such as hydroxytyrosol) reacts with specific acid molecules.

“Oleacein is a biphenolic compound. It contains two phenolic hydroxyl groups, which makes it an especially powerful antioxidant,” said Prokopios Magiatis, an associate professor of pharmacognosy at the National and Kapodistrian University of Athens.

“It’s an ester of hydroxytyrosol, but unlike hydroxytyrosol, which is water-soluble, oleacein is amphiphilic. It can dissolve in both water and fat,” he added.

Oleacein’s vast potential in health

Oleacein’s dual solubility may help explain its effectiveness inside the human body, as it allows broad interaction with both lipid and aqueous environments.

Because of its structure, oleacein can integrate into the body’s lipid particles, including low-density lipoproteins (LDL), often known as “bad cholesterol.” Once incorporated, it might offer a protective shield.

“Oleacein can be incorporated in LDL particles and protect them from oxidation,” Magiatis explained. “And that is crucial, because the oxidation of LDL cholesterol is one of the first steps in the formation of arterial plaques.”

Oleacein also shows promising anti-inflammatory properties. Its mechanisms are quite different from those of better-known compounds, such as oleocanthal, which is also found in extra virgin olive oil.

“Oleacein does not inhibit COX,” Magiatis remarked, referring to the cyclooxygenase enzymes that oleocanthal targets, and which are responsible for producing prostaglandins, molecules that promote inflammation and pain.

“But oleacein reduces the expression of TNF‑α and certain interleukins. These are cytokines that drive the inflammatory response,” Magiatis said.

Cytokines are small proteins that act as messengers between cells in the body. Therefore, oleacein modulates the body’s sensitivity and reaction to inflammatory molecules.

“It can also suppress enzymes involved in inflammation. So we’re seeing a complementary mode of action,” Magiatis said.

Oleacein’s health impacts may also extend to metabolism.

According to a clinical study published in 2024, 17 pre-diabetic adults consumed extra virgin olive oil rich in oleacein and oleocanthal.

The results, compared to a standard olive oil, were significant, as inflammatory cytokines dropped, antioxidant status improved, lipid oxidation decreased, and both body mass index and glucose significantly enhanced.

The researchers concluded that oleacein-rich olive oil can contribute to improved metabolic health in individuals at high risk.

Oleacein in brain health research

Given its broad implications in the body’s chemistry, research has recently focused on how oleacein impacts brain function.

Several neurology studies in cell cultures and animal models have demonstrated that oleacein might play a role in protecting the brain.

Magiatis’s lab, in collaboration with researchers at the University of Valladolid in Spain, tested oleacein in an animal model of multiple sclerosis.

“It was very clear: oleacein protected the brain. We saw anti-inflammatory activity in nerve cells and strong antioxidant effects at the site of the damage,” Magiatis explained.

That preclinical study laid the groundwork for a human clinical trial in patients with multiple sclerosis, which has now been completed and is awaiting publication.

Meanwhile, other groups are exploring oleacein’s neuroprotective potential.

A 2023 paper demonstrated that oleacein acts as a TrkB receptor agonist, thereby promoting the expression of brain-derived neurotrophic factor, a key protein involved in neuroplasticity.

The authors noted reduced depressive behavior and inflammation in mice treated with oleacein.

The journey has just begun

While oleacein is at the forefront of research on extra virgin olive oil’s most active phenols, Magiatis and Fátima Paiva-Martins said research is still in its early stages.

Much of what is known today about oleacein’s impact comes from lab and animal models, and although human studies are emerging, much remains to be explored.

“The biological effects attributed to olive oil consumption are essentially due to the intake of lipophilic derivatives of oleuropein, such as oleacein,” Fátima Paiva-Martins noted.

“The metabolites responsible for oleacein’s biological activity have not yet been fully identified or characterized,” the researcher cautioned. “We know hydroxytyrosol metabolites play a role, but the full picture remains unknown.”

“Oleacein is a highly reactive molecule and can form adducts with proteins, though the impact of this reactivity on its biological activity and the systemic effects observed after olive oil consumption is still not fully understood,” she added.

Research is ongoing, focusing on the complexity of oleacein.

“We’re in a good place,” Magiatis said. “We have made progress, and soon new research will clarify key aspects such as oleacein’s absorption, metabolism and bioavailability.”

How to select EVOO high in oleacein

Current knowledge about oleacein suggests that consumers interested in its benefits should look for high-quality olive oils with a high polyphenol count.

Freshly produced olive oils that provoke a slight cough or a peppery kick are good candidates for delivering oleacein, as such sensory irritation is often a sign of both oleacein and oleocanthal.

Besides storing extra virgin olive oil in a cool, dark place, research suggests that oleacein levels can be well preserved at wine-cellar temperatures (12 to 14 °C).

According to Magiatis, what makes the difference in the healthy impact of extra virgin olive oil is not a single significant component, but rather the whole product.

“In my personal view, olive oil is the best way to get those healthy compounds in your body,” he said. “It is natural, balanced, and it comes with dozens of other compounds that work together. Nothing can compare to that.”

A new study, published in a special issue of the journal Foods, indicates that the mechanisms by which it does so open up new avenues of treatment for this and other colorectal diseases.

Ulcerative colitis is a chronic inflammatory bowel disease that affects the colon and rectum, leading to persistent mucosal inflammation and ulcer formation. 

Patients with ulcerative colitis typically experience symptoms such as diarrhea, abdominal pain, rectal bleeding and unintended weight loss. 

In addition, there is a significantly higher risk of colorectal cancer associated with the disease, estimated to be two percent after ten years, eight percent after 20 years and 18 percent after 30 years.

Current treatments, such as aminosalicylates, corticosteroids and immunosuppressants, are of limited value and often come with serious side effects, including hypertension, bone loss and organ toxicity. 

Given this and the debilitating nature of the condition, there is widespread recognition of the need for alternative treatment candidates.

A phenolic compound with natural anti-inflammatory and antioxidant properties, oleuropein extracted from extra virgin olive oil, has previously been shown to be effective at alleviating ulcerative colitis. However, little of the literature has focused on the exact mechanisms by which it does so.

Previous studies have suggested that oleuropein may alleviate symptoms of ulcerative colitis by reducing oxidative stress and modulating immune responses. 

The researchers focused on the interactions between oleuropein and gut microbiota, hypothesizing that it could protect the colon by modulating microbial populations and their metabolic products.

Using mouse models, orally administered oleuropein was shown to significantly improve clinical symptoms, such as weight loss and colon shortening, indicating physical tissue repair. 

At the cellular and molecular levels, oxidative stress-related abnormalities, such as elevated myeloperoxidase activity, were reversed, suggesting the mitigation of oxidative damage.

Meanwhile, pro-inflammatory cytokines were suppressed through the NF-κB signaling pathway, and tight junction protein levels were increased.

To confirm the role of gut microbiota, the microbiota were transferred from treated to untreated mice. Without any additional intervention, ulcerative colitis severity was reduced, indicating that microbial changes induced by oleuropein play an important role in the compound’s therapeutic effects. 

These findings were further enforced by 16S rRNA sequencing, which revealed increased levels of Lactobacillus and decreased levels of Proteobacteria, a group strongly associated with inflammatory gut responses and numerous diseases.

In addition to microbial composition, the researchers investigated the impact of oleuropein on bile production. 

Ulcerative colitis patients exhibit elevated levels of primary bile acids, produced by the liver, and reduced levels of secondary bile acids, which are created through bacterial interaction within the colon. 

Such imbalances inhibit the growth of beneficial bacteria and promote pathogen growth. Analysis showed that oleuropein treatment significantly restored levels of bile acid, including key secondary bile acids such as hyodeoxycholic acid.

Because the hyodeoxycholic acid levels differed substantially between the treated and untreated groups, their independent effects were studied. 

Hyodeoxycholic acid administration reproduced many of the protective effects of oleuropein, including improved weight maintenance, reduced colon shortening and reduced tissue inflammation. Like oleuropein, hyodeoxycholic acid also suppressed NF-κB signaling and restored tight junction protein expression.

These findings suggest that oleuropein also acts in part by boosting hyodeoxycholic acid levels, which in turn activate FXR, a receptor known to play a key regulatory role in chronic intestinal inflammation, and suppress pro-inflammatory signaling.

The researchers conclude that oleuropein not only relieves symptoms but also addresses underlying pathogenic processes. These include inflammation, oxidative stress, barrier dysfunction and microbial imbalance. 

Its apparent therapeutic effects on a complex regulatory network of multiple pathways associated with numerous diseases, including colorectal cancer, make it a strong candidate for new alternative or complementary treatments and further research.

If approved by EFSA, health claims can be used to enhance the credibility of a product’s healthy profile and increase consumer trust. They can also be used on labels and to differentiate marketing strategies across European Union countries.

More specifically, the Panel on Nutrition, Novel Foods and Food Allergens did not find sufficient evidence in the application submitted by an Italian university regarding the impact of polyphenols on the maintenance of normal levels of the so-called “good cholesterol,” high-density lipoprotein cholesterol (HDL‑c) concentrations.

The Italian Aldo Moro University of Bari had proposed the following health claim: “Olive oil polyphenols contribute to normal lipid metabolism.”

In drafting its opinion, the panel acknowledged that the application included a published systematic review and meta-analysis of ten human intervention studies investigating the effect of olive oil polyphenols on blood HDL‑c concentrations.

While the panel acknowledged that some studies reported significant impacts of polyphenols, it also noted key shortcomings in the evidence.

One crucial study highlighted an increase in HDL‑c in adult males after a three-week controlled intake of olive oil polyphenols. However, the panel emphasized that these findings had not been replicated in other studies and therefore could not be considered conclusive.

Moreover, the panel found that a three-week study period was insufficient to draw reliable conclusions about the long-term impact of continued olive oil polyphenol consumption.

Another weakness identified was the lack of convincing evidence explaining how olive oil polyphenols could exert the claimed effect.

The panel concluded that the evidence provided was not sufficient to establish a cause-and-effect relationship between the consumption of olive oil polyphenols and the maintenance of normal HDL‑c concentrations.

In its more recent opinion, the panel rejected the application of a producer association that sought to validate extra virgin olive oil’s impact on reducing the so-called “bad cholesterol,” low-density lipoprotein (LDL-cholesterol)and systolic blood pressure.

According to the Spanish-based international association QvExtra! Internacional, such evidence would support the role of extra virgin olive oil in reducing the risk of coronary heart disease.

QvExtra! proposed the following wording for the health claim: “Naturally present phenolic compounds in any virgin olive oil reduce the LDL-cholesterol in blood and arterial systolic blood pressure. A reduction of LDL-cholesterol in blood or arterial systolic blood pressure reduces coronary heart disease.”

Upon reviewing the application, the Panel noted the significance of a randomized controlled trial (Fernández-Castillejo et al., 2016) that demonstrated a reduction in LDL‑c after three weeks in hypercholesterolemic individuals. 

However, the panel emphasized that no other studies confirmed this result.

Several larger studies conducted in healthy individuals also failed to replicate those findings.

The panel also found that no human trials demonstrated a reduction in systolic blood pressure through the consumption of olive oil polyphenols.

The application suggested a plausible mechanism of action, but without consistent evidence of actual blood pressure reduction.

Additionally, the panel noted that all reported benefits were observed in short-term studies. None of the trials presented lasted at least eight weeks, which EFSA considers the minimum duration necessary to demonstrate stable effects on blood lipids or blood pressure.

Commenting on EFSA’s decisions, researcher Ítala Marx emphasized the need for more robust research on extra virgin olive oil and its health benefits.

“We know, and feel, that olive oil goes far beyond flavor. It carries bioactive compounds, including hydroxytyrosol and its derivatives, which have been associated with antioxidant and anti-inflammatory effects (among others),” Marx wrote on LinkedIn.

“But the truth is, when we put all of this to the test under the highest scientific standards, we still don’t have enough human evidence to confirm a cause-and-effect relationship for lowering LDL-cholesterol or systolic blood pressure,” she added.

According to Marx, several aspects of extra virgin olive oil research require improvement.

“We need larger clinical trials, long-term studies that can show whether the effects persist with continuous use, clear protocols with well-defined doses of phenolic compounds, and a deeper exploration of molecular mechanisms to demonstrate how and why these compounds act in the human body,” she said.

All EFSA-approved health claims are included in the European authority’s Register of Health Claims.

One approved health claim states that “olive oil polyphenols contribute to the protection of blood lipids from oxidative stress.”

This claim is based on evidence indicating that high-quality olive oil protects low-density lipoprotein (LDL) particles from oxidative damage. However, it can only be used when the oil contains at least five milligrams of hydroxytyrosol and its derivatives per 20 grams of product.

New research published in Food Chemistry compiled years of studies on how malaxation temperature, time, oxygen exposure, and the addition of water impact the content and profile of polar phenolic compounds, especially secoiridoids, a subclass of phenols.

“These are the most representative phenolic class in olive oil, and they’re the ones most transformed during malaxation,” Ítala Marx, a postdoctoral researcher at the University of Córdoba and co-author of the research, told Olive Oil Times.

During malaxation, larger precursor molecules, such as oleuropein and ligstroside, naturally produced by the fruits, are converted – biotransformed – by enzymes.

Those convey smaller, highly bioactive compounds such as oleocanthal and oleacein, which are linked to olive oil’s pungency, bitterness and antioxidant power.

Decades of research have shown that daily consumption of olive oil rich in phenols produces significant health benefits.

Furthermore, the complete phenolic profile of extra virgin olive oil is deeply intertwined with its aromas and flavors.

“Phenolics are responsible for bitterness and pungency. So if you increase them, you naturally improve sensory complexity,” Marx said. “The consumer wants that ‘green’ flavor, that bitterness. These are linked to the phenolic profile.” 

“That’s why we focused on secoiridoids,” she explained.“They’re at the core of both the sensory experience and the health-related value of extra virgin olive oil.”

“I started this work during my PhD,” Marx added. “My program was completely developed in industrial olive oil mills. All campaigns, from 2019 to 2022, were focused on how to optimize extraction to improve oil’s phenolic content, and malaxation was the core of my research.”

The review paper focused on how the enzymatic biotransformation happens during malaxation and how sensitive the process is to malaxation conditions.

“Everything depends on the olive cultivar. You can’t apply the same temperature and time and expect the same result from different olives,” Marx remarked.

The influence of cultivar, or genotype, is perhaps the strongest variable. “Genotype is the main factor that impacts olive oil’s phenolic composition,” Marx said.

This was made evident by studies in which dozens of olive cultivars were grown under identical conditions and extracted using the same technology and procedure.

“They showed wide variation in phenolic profiles,” Marx said. 

“Even Arbequina, usually considered low in phenolics, can surprise you,” she added, hinting at the profound impact that different farming environments can convey.

“If you extract oil from Arbequina in an intensive orchard, or from Arbequina in a traditional setup, the result will be completely different,” she explained.

Marx introduced research conducted in the Almeria desert, in Andalusia, where Arbequina and Picual olive varieties were cultivated in the same desert conditions.

“It’s a commercial brand. When we analyzed the olive oils, the Arbequina had over 1,000 milligrams per kilogram of phenols. That’s not typical,” she said.

According to Marx, the highly stressful environment of the desert boosted the phenolic synthesis.

“We saw the same happening with Arbequina cultivated in Brazil, amounts of phenolics higher than you’d expect,” she said.

Even more interesting than the total amount of phenols, it was the phenolic profile of the olive oils.

“We observed more oleacein and more oleocanthal in Arbequina compared to Picual. Meanwhile, Picual was richer in glucosides like oleuropein and ligstroside,” Marx said.

“The total amount may be similar, but the profile is different. And that impacts both sensory traits and oxidative stability,” she added.

The phenolic profile is essential. “Take oxidative stability. It is not just about how many phenolics are present, but which ones,” Marx said.

“Oleacein and oleocanthal, which Arbequina has more of, don’t stabilize oil as well as oleuropein glucoside, which is more common in Picual,” she added.

When it comes to milling the olives, these differences should be carefully considered.

“If you have Arbequina in an intensive orchard, and you know its usual phenolic weakness, you might invest in technologies like pulsed electric fields or oxygen control to improve it,” Marx said. 

“But if you’re working with Arbequina from a traditional, stressed environment, you may already be starting with a higher phenolic baseline,” she added.

These nuanced differences point towards a future of tailored extraction strategies.

“It’s not just about the cultivar anymore. It’s about cultivar, plus environment, plus processing,” Marx said. “And if you want to make excellent extra virgin olive oil, you need to take into account all three.”

The paper examined how malaxation temperature and time impact phenolic content.

Studies have shown that moderate temperatures between 20°C and 30°C generally promote better extraction of phenolics, while excessive heat leads to degradation.

“The effect follows a bell shape. We reach an optimal point, often around 20 to 30 minutes of malaxation, and then phenolic content starts to drop,” Marx said. “Longer malaxation promotes oxidation, degradation and enzymatic breakdown of phenolics.”

Still, the olive cultivar is always worth considering.

“You can’t say 25 °C and 30 minutes is always best. For some cultivars, like Arbequina, 45 minutes at 25 °C may work better,” she explained, hinting at the specific analyses on specific cultivars cited in the review paper.

One of the most transformative findings was related to oxygen. “Oxygen promotes phenolic degradation,” Marx noted.

“So when we eliminate it, by using vacuum systems or even controlling the oxygen atmosphere, we can retain more phenolics in olive oil,” she added.

More specifically, some industrial-scale tests using high vacuum during malaxation showed increases of 25 to 48 percent in phenolic content, especially in secoiridoid derivatives.

Even partial oxygen control can help.

“Just reducing the headspace oxygen in the malaxer chamber can make a difference. And cultivars respond differently, some are more sensitive than others,” she remarked.

Many milling processes are carried out by adding water. It is a common way to control the consistency of olive paste, which is what results from crushing olives, and an easy way to improve yield.

But research confirmed that it comes with a hidden cost.

“We tested different amounts of water in industrial mills, again with Arbequina,” Marx said. “And without water, we obtained olive oils with higher phenolic content.”

The reason is chemical. Phenols are hydrophilic. When water is added to the olive oil paste in the malaxer, the water takes the phenolic compounds from the paste.

“If we don’t add water, we have the chance to retain them, to have them stay with the olive oil,” Marx explained.

The research demonstrated the promise of recent, non-thermal extraction technologies.

“Pulsed electric fields, ultrasound and microwaves. All of these can increase both phenolic content and olive oil yield. And unlike traditional methods, they don’t degrade the sensory profile,” Marx said.

Adding temperature, time, or water to improve yields is a well-established practice at many olive oil mills.

“Yes, that worked for yield, but destroyed the phenolics and the taste,” Marx said. “Now, with these new technologies, we can have both: higher phenolics and better sensory attributes.”

Overall, the phenolic profile and total phenols combine to determine an olive oil’s stability, taste and health benefits. Marx pointed out that the research will continue.

“We need to move toward cultivar-specific guidelines,” she concluded. “With the data we have now, and the technology available, it’s possible to produce excellent olive oils, even from cultivars not traditionally known for phenolics.”

The study confirmed, among other findings, that hydroxytyrosol significantly reduces the oxidation levels of LDL cholesterol (the so-called ‘bad cholesterol’), thus potentially improving cardiovascular health and reducing associated risks.

“Some extra virgin olive oil phenols contain precursors of this molecule. Once we consume extra virgin olive oil, our body reacts by producing hydroxytyrosol,” study co-author María-Carmen López de las Hazas told Olive Oil Times.

López is a researcher at the Laboratory of Epigenetics of Lipid Metabolism at the Research Institute on Food and Health Sciences (IMDEA) in Madrid.

The study involved a clinical trial during which 12 healthy participants received first a single 25-milligram dose of hydroxytyrosol, followed by a daily dose of 25 milligrams of hydroxytyrosol for one week.

The researchers documented a measurable decrease in oxidized LDL (oxLDL) levels following one week of daily hydroxytyrosol intake.

Reducing oxLDL is crucial as it plays a key role in developing atherosclerosis and cardiovascular diseases.

“We observed notable reductions in LDL oxidation after just one week, which surprised us because we initially believed it would take much longer to see any effect,” Alberto Dávalos, an IMDEA researcher and head of the project, explained.

“The potency of hydroxytyrosol as an antioxidant creates an antioxidant-rich environment in the plasma, protecting LDL from oxidative stress,” he added.

The researchers focused on extracellular vesicles to better understand the mechanisms behind hydroxytyrosol’s antioxidant activity. These vesicles are small molecules secreted by cells and circulate throughout the body, carrying substances and messages to other cells and tissues.

“We call them the cellular WhatsApp. They are small lipid-bound vesicles secreted by cells across all kingdoms of life, serving as critical communication vehicles between cells,” López and Dávalos explained.

Extracellular vesicles transport various biological molecules, including proteins, lipids and nucleic acids like microRNAs (miRNAs), influencing physiological processes and intercellular communication.

The research showed that hydroxytyrosol intake increases extracellular vesicle secretion and modulates their size and cargo potential, significantly impacting intercellular signaling pathways related to health and disease.

Additionally, researchers found that hydroxytyrosol intake affects miRNAs transported within extracellular vesicles. Micro ribonucleic acid molecules (miRNAs) are essential for regulating gene expression by determining the amount of protein produced from a gene.

miRNAs are involved in various physiological processes, including inflammation and cardiovascular health, and may protect against certain cancers and neurodegenerative conditions.

According to the researchers, hydroxytyrosol intake induced notable changes in the activity of specific miRNAs, with some becoming more active and others less active.

“miRNA-124, typically elevated in cardiovascular complications, was significantly decreased, which is beneficial,” López and Dávalos noted.

“Conversely, miRNA-590, important for heart repair after myocardial infarction, increased, indicating potential cardioprotective effects,” they explained.

“These miRNAs might serve as biomarkers or therapeutic targets, highlighting the promising impact of hydroxytyrosol,” the researchers emphasized.

“However, the long-term implications and exact mechanisms still need clarification through extended studies,” they cautioned.

Hydroxytyrosol’s potential impact on human health is also related to some unique properties researchers are exploring, especially its ability to cross the blood-brain barrier.

“Something relevant about hydroxytyrosol is that this is one of the few phenolic compounds that can be found in the brain, at least in several animal models,” Dávalos noted.

“Normal polyphenols cannot transport through the blood-brain barrier unless they have a transporter or a specific chemical structure. One possibility for how they cross the barrier is transport within extracellular vesicles,” he explained.

The blood-brain barrier is composed of highly specialized cells lining brain vessels. It serves as a protective shield that prevents bacteria, viruses and other potentially harmful molecules from accessing the brain. The barrier also regulates the entry of nutrients and other crucial substances.

According to the researchers, this discovery could have significant implications if future studies confirm that hydroxytyrosol is transported via extracellular vesicles in a larger population.

“This is relevant from a dietary point of view because when you consume polyphenol-rich extra virgin olive oil, a certain amount of hydroxytyrosol can be incorporated within extracellular vesicles, increasing its potential to cross the blood-brain barrier,” Dávalos explained.

“This mechanism opens exciting therapeutic possibilities, particularly regarding neurodegenerative diseases,” the researchers pointed out.

Still, the scientists emphasized that additional studies are necessary to thoroughly understand this cellular behavior and its implications.

“It is potentially a positive result to see hydroxytyrosol crossing the barrier, but increased permeability to beneficial substances transported in extracellular vesicles could also imply increased vulnerability to other compounds,” Dávalos warned.

“Additionally, if the blood-brain barrier is permeable enough to allow hydroxytyrosol through, other barriers like the placental barrier might also be crossed when transported in extracellular vesicles. This is an entirely new area to explore,” the researchers said.

According to the scientists, future research might investigate the relationship between hydroxytyrosol intake and endogenous antioxidant mechanisms, which are crucial processes naturally activated by the human body to combat oxidative stress.

“As humans, we obtain antioxidants through two mechanisms. One is endogenous, where our body produces antioxidants naturally. The other is exogenous, where we consume antioxidants through our diet,” López explained.

She noted that introducing potent antioxidants, including hydroxytyrosol, might decrease endogenous antioxidant production.

According to the researcher, this mechanism might not always be beneficial, especially under conditions of high oxidative stress.

“What could potentially happen is that consuming hydroxytyrosol initially helps fight oxidative conditions, but when hydroxytyrosol’s effect is exhausted, our endogenous antioxidant systems might remain inactive for a while, leaving us vulnerable,” López and Dávalos explained.

The researchers mentioned past experiences with antioxidants used in cancer prevention trials in the United States during the 1980s and 1990s.

“The intake of those synthetic antioxidants in large clinical trials led to negative outcomes, with increased mortality, especially among smokers,” they recalled.

However, the scientists highlighted a crucial difference: hydroxytyrosol is a naturally occurring molecule introduced under normal dietary conditions.

“This significantly changes the scenario. A balanced supplementation of antioxidants through dietary habits might be the optimal strategy to harness the best possible effects of hydroxytyrosol,” López and Dávalos concluded.

“Further studies are needed to fully understand these aspects,” they emphasized.

Àlya, a monovarietal produced from Chetoui olives, recently won a Silver Award at the 2025 NYIOOC World Olive Oil Competition.

“I already knew Chetoui was rich in polyphenols, but when the laboratory returned the results, we were surprised by just how high the polyphenols were in our extra virgin olive oil,” Ayed said.

Ayed’s family has cultivated the renowned Tunisian olive variety in two locations for decades. The award-winning olive oil is produced from approximately 5,000 olive trees, exposed to the elements on a hillside grove.

The local microclimate might be one reason for the exceptionally high polyphenolic content, which Ayed said was found to exceed 1,800 milligrams per kilogram of olive oil. “It has changed over the years, and recently, the trees underwent significant stress,” she noted, referring to the severe drought affecting Tunisia in recent seasons.

“When these conditions occur, the tree defends itself by increasing its polyphenols,” she added. “To stay strong, the tree develops these compounds. When we consume them, they help protect us as well. It’s an amazing example of synergy between nature and humans.”

Due to its own olive mill and dedicated workforce, the farm managed a very early harvest and immediately pressed the olives. “This also enhanced the phenolic profile of our product,” Ayed said.

Last August, the Àlya brand was launched to promote extra virgin olive oil as a health remedy, not just a food product. “The word Àlya itself means ‘to elevate your health,’” Ayed said.

“The whole purpose of this project is to take olive oil, which we know is excellent for health, and give it a form factor that allows customers to use it daily to enhance their well-being,” she added.

Ayed referenced recent research showing that consuming extra virgin olive oil before meals can improve digestion. “Promoting it for this reason is mostly a new approach,” she said.

According to Ayed, the project was inspired by rediscovering ancient wisdom surrounding olive oil.

“It all started with my own experience. When I moved to the United States, I worked in a stressful environment, ate poorly and my health suffered,” Ayed said.

Ayed followed her physicians’ recommendations, taking supplements, prebiotics and probiotics.

“I was taking many things, but I wasn’t improving. Once back in Tunisia, my grandmother insisted I consume olive oil each morning on an empty stomach, with a bit of bread,” Ayed said.

“That’s when my health began improving significantly, reducing inflammation and normalizing digestion,” she added.

Ayed noted that a growing body of research supports the daily consumption of extra virgin olive oil, particularly extra virgin olive oil rich in polyphenols.

“We began exploring studies showing extra virgin olive oil benefits for digestion and gut health—effectively acting as a prebiotic and helping nutrient absorption,” Ayed said.

The new project aims to introduce these benefits to the U.S. market. “Many Americans struggle with insulin resistance and chronic conditions often linked to diet,” Ayed said. “So, that’s where I come from.”

“I blended this ancient remedy we’ve used forever with modern health practices. It’s as if ancient remedies meet modern health,” she added.  “Our extra virgin olive oil is very bitter, green and peppery. We’ve been cultivating these trees for over 20 years. We produce small batches, always ensuring the highest quality.”

According to Ayed, the biggest challenge for producers of high-quality extra virgin olive oil is reaching customers and raising awareness about the product’s health benefits.

“Through social media and live events, we educate people about extra virgin olive oil health benefits and its effectiveness in managing specific health conditions,” Ayed said.

A key issue remains the quality of extra virgin olive oil available to American consumers. “Many olive oils sold in the U.S. aren’t very good, often not fresh at all,” said Ayed, emphasizing that Àlya is not intended as a mainstream product but as health support for discerning consumers.

As a result, Àlya’s production will not expand in the short term. “Our primary goal isn’t expanding production,” she said. “It’s maintaining our high polyphenol levels and demonstrating to customers that we never compromise quality.”

Despite steadily increasing olive oil production—the International Olive Council forecasted Albania would produce 30,000 metric tons in the 2024/25 crop year—Danaj said the southeastern European country would never compete with other large olive oil producers in the region in terms of quantity.

 ”We’re competing to have the best flavor and aroma, bitterness and pepperiness,” he told Olive Oil Times, “but we also are competing to have as many polyphenols as possible while keeping everything in balance.”

To that end, Danaj and the rest of the team at Donika Olive Oil celebrated winning a Gold Award for their Premium brand, an organic Kalinjot monovarietal, at the 2025 NYIOOC World Olive Oil Competition. The company previously won a Silver Award for the same oil in 2024.

While the producer performed little differently between the two harvests, Danaj said an upgrade to the malaxer and better storage conditions may have contributed.

His milling team replaced the blades of the company’s malaxer with hollow blades that can be cooled with water, allowing them to keep the malaxing temperature at 22ºC. 

“The blades remain at a constant temperature, and before they used to heat up because of the movement,” he said, allowing the paste to reach 25 ºC. 

Danaj said the goal is to keep the paste from overheating and losing favorable organoleptic properties.

Once the extra virgin olive oil has been decanted and filtered, it is pumped into underground storage tanks until it is bottled to order. “The olive oil has the least amount of contact with oxygen as possible,” Danaj said. 

“There is still room for improvement in storage and filtration,” he added. “We can do a much better job.”

Next year, Danaj will skip the decanting step and filter the oil immediately after production, increasing the number of filter plaques the mill uses and raising the production cost.

“Right now, we are more mission-based than profit-focused,” he said. “Of course we’re making money to sustain ourselves, but we truly believe in producing the best product… and we believed that leaving the olive oil to decant was diminishing this.”

Danaj will skip the decanting step mainly to preserve the naturally abundant polyphenols in Kalinjot olives. Donika Premium has about 800 milligrams per kilogram, far exceeding the 250 required for the medicinal claims required by E.U. Regulation 432/2012.

He aims to reach 1,000 milligrams per kilogram of polyphenols while maintaining a harmonious frutiness, bitterness and spiciness.

Along with the climate and soil conditions of the southern region of Vlorë, Danaj’s team harvests the fruit early from the crowns of the trees, selecting the olives with the most exposure to the sun. 

While harvesting early sacrifices quantity, it allows for more polyphenols in the resulting extra virgin olive oil.

The harvested olives are placed into baskets and transported to the mill in three-hour intervals to complete the milling process as quickly as possible.

Among the annual challenges of the olive harvest in Albania are the country’s mountainous terrain and the poor infrastructure in some rural areas.

“ The terrain here is very difficult and hilly… sometimes you can only transport olives with donkeys or horses… to a main road to take to the mill in a truck,” Danaj said. “When everyone harvests at the same time, there can be bidding wars for the limited number of donkeys and trucks.”

Due to the mountainous terrain, it is also impossible for most producers to mechanize the harvest. Fragmented land ownership means that many farmers own small plots of land, making it more difficult to achieve economies of scale.

“ We cannot [produce at scale], but we can produce very high-quality olive oil from the local variety,” Danaj said.

He believes focusing on its Albanian identity will help raise brand awareness in Donika’s export markets—the company mainly sells olive oil in the United States but is also working to enter Australia, China, Japan, South Korea and the United Kingdom—and promote Albanian extra virgin olive oil abroad more generally.

Donika is named after Donika Kastrioti, the grand princess of Albania who was born in what is now Vlorë County and married Gjergj Kastrioti. 

Kastrioti, who was viewed as one of the country’s national heroes, and his wife fought for Albania’s independence from the Ottoman Empire in the mid-fifteenth century.

“ One of the reasons we started Donika is to do what Italy did in the 1980s,” Danaj said, referencing the Made in Italy initiative, which is partially credited for the country’s decades-long dominance in the U.S. olive oil market. “We’re focusing on Albania and Kalinjot, which many people have never heard of.” 

Danaj said there are signs that the Albania and polyphenol-centric marketing strategies are working. He said some stores in California, where the olive oil retails at a premium price, have partly driven sales by telling the brand’s story.

“We have the footprint of success. We just haven’t done it massively yet,” Danaj said. “I think this is going to be our year, where we aim to have as many retail partners as possible [telling that story] and increase our online sales.”

“Our main objective is… to understand how extra virgin olive oil rich in phenolic compounds can inhibit the formation of some compounds including advanced glycation end-products in cooked food,” Ítala Marx, a postdoctoral researcher at the University of Córdoba and principal investigator for Phenols4Health, told Olive Oil Times.

Advanced glycation end products are formed when protein or fat combine with sugar in the bloodstream. They contribute to increased inflammation and oxidative stress associated with diabetes and cardiovascular disease.

“Our previous results indicated that phenolic compounds in extra virgin olive oil can minimize lipid oxidation and in this sense, due to its high antioxidant capacity, we hope that it also inhibits the formation of these compounds,” Marx added.

The researchers’ secondary goal is to identify cooking methods that preserve polyphenols, which degrade when exposed to heat, light and oxygen.

For example, Marx said the team has been testing different cooking methods, looking at emerging alternatives such as air frying. 

“We want to understand how different cooking methods can affect not only the phenolic composition but also the inhibition of advanced glycation end-products and the reduction of lipid oxidation in cooked foods,” she added.

The project, involving scientists from the University of Córdoba in Spain and the University of Campinas in Brazil, has already developed an extra virgin olive oil-based cracker and is working on producing flour enriched with their novel byproduct.

In one formulation, the researchers prepared the crackers similarly to regular crackers, replacing sunflower oil with Picual extra virgin olive oil produced in the Tabernas Desert in the Andalusian province of Almería. They also swapped white flour for gluten-free chickpea flour.

Due to an early harvest, the natural genetics of the Picual variety and the climate of the Tabernas Desert, the researchers selected extra virgin olive oil with a very high polyphenol content of 1,500 milligrams per kilogram.

As a result, Marx said the sensory properties of the extra virgin olive oil crackers were distinct, with a pronounced bitterness and characteristic smell of fresh extra virgin olive oil. The researchers also tested cracker formulations using refined olive oil as a control.

They aim to create products that appeal to various consumers and are healthier alternatives to typical snack foods.

Additionally, the researchers produced crackers using chickpea flour enriched with their proprietary olive oil production byproduct. 

“To ensure phenolic enrichment of the crackers and propose an upcycling strategy for the byproducts of olive oil production, we are developing formulations with enriched chickpea flour, which can further contribute to the reduction of lipid oxidation, and which we hypothesize will also prevent the formation of advanced glycation end-products”, Marx said.

“ Our previous results in other foods, including fried potatoes and breaded chicken, showed that it was possible to reduce lipid oxidation using extra virgin olive oil and enrich the foods with antioxidant compounds using the olive production byproduct,” she added.

The Phenols4Health project is part of a broader trend in the Mediterranean of researchers searching for alternative uses for olive oil production byproducts.

A 2024 study identified freeze-dried olive powder, a byproduct of table olive production that retains phenolic compounds and monounsaturated fatty acids, as a healthy ingredient to enrich baked goods, seasonings and health supplements.

Separate initiatives have repurposed olive waste into an eclectic range of products from biofuel and bioplastic to building insulation, supercapacitors and animal feeds.

For her part, Marx believes snacks enriched with the olive oil byproduct will be a growing source of revenue for olive oil producers, and new companies will specialize in making these phenolic-rich snacks.

Indeed, once the Phenols4Health project ends in May 2026, Marx is considering launching a start-up that would produce a new generation of functionally enriched foods.

“My main objective is to develop new products… that are nutritional, sustainable and healthy, as well as to create new avenues and sources of revenue for olive oil producers, ” she said.

“These results allow us to think outside the box and propose the development of new, healthy, gluten-free snacks,” Marx concluded.

The supplement, sold commercially as Momast Plus 30 Bio (MP30B), is enriched with hydroxytyrosol, one of olive oil’s primary polyphenols, using a patented technique to extract the compound from olive mill wastewater.

Bioenutra, the company that manufactures MP30B, was not involved in the study.

Previous studies have found that the supplement exerts anti-inflammatory effects and removes reactive oxygen, which mitigated heart infections in in vivo studies.

In ex vivo studies, MP30B was also found to decrease the stiffness of the thoracic artery, which is thought to precede increased blood pressure.

The research also demonstrated that MP30B did not significantly alter the heart’s ability to pump blood effectively or impact the blood vessel function and health, known as cardiac and vascular parameters, in ex vivo studies.

“Based on these findings, we posit MP30B as a promising extract for cardiovascular disease prevention, and its specific antibacterial properties suggest its utility in preventing cardiac infections,” the researchers wrote.

Along with the promising health results from the study, the researchers said finding new uses for olive oil production byproducts helps increase the sustainability of the production process and substitutes a cost for millers with an additional revenue stream.

An estimated 30 million cubic meters of olive mill wastewater are produced yearly in the Mediterranean basin. Due to its high content of phenolic compounds, this wastewater must be treated before disposal.

“Olive mill wastewater poses an important waste management problem since the lack of conventional treatment can counteract its high toxicity,” the researchers wrote. “However, phenolic compounds in the wastewater represent an opportunity to ‘upcycle’ this waste to obtain high-added-value products.”

Their study, conducted on guinea pigs, found that Momast Plus 30 Bio inhibited the ability of enzymes to synthesize nitric oxide, a free radical, the overproduction of which can promote inflammation and oxidative stress.

“Our results suggest that MP30B can also interfere with inflammatory processes affecting the cardiovascular system by counteracting the deleterious effects caused by uncontrolled nitric oxide biosynthesis,” the researchers wrote.

They also found hydroxytyrosol’s antibacterial properties in MP30B, especially against infective endocarditis, a bacterial or fungal heart infection with a relatively high in-hospital mortality rate.

“Streptococci are among the most frequent causes of infective endocarditis,” the researchers wrote. “MP30B has actions on all types of streptococci tested.”

“Comparing the results of MP30B with those obtained using the reference antibiotic levofloxacin on Streptococcus pyogenes ATCC or FL, it is observed that MP30B is more potent both as a bactericidal and as a bacteriostatic on Streptococci FL; contrary to what was observed for levofloxacin whose actions are more significant in ATCC bacteria,” they added.

The researchers concluded that the hydroxytyrosol-enriched dietary supplement demonstrated potential as a food supplement to prevent cardiovascular diseases and suggested that further research should investigate its impact on breast cancer.

“Studies on the cardiotoxic effects of anti-tumor therapies demonstrate the protective action of hydroxytyrosol in breast cancer cardiotoxicity, increasing the potential applications of MP30B,” they wrote.

The polyphenols in question, hydroxytyrosol and tyrosol, were extracted from olive milling waste, making the study another example of the possibilities for the olive industry to contribute to the circular economy and increase sustainability.

The study, conducted by researchers from the Zooprophylactic Experimental Institute of Umbria and Marche and the University of Perugia’s veterinary medicine department, was conceived to assess the potential of olive industry waste products as aquacultural nutritional supplements in the context of global environmental concerns and the European Green Deal.

The experiment was conducted on 600 gilthead sea bream, randomly assigned to two dietary groups of 300. Each group was then divided into three subgroups of 100 fish placed in separate indoor tanks.

Compared to the control group, fish fed with the experimental diet showed a tendency to increase in weight in the intermediate phase (117 percent weight gain compared to 82 percent), and a higher weight increase was recorded at the end of the experiment (177 percent compared to 125 percent).

A significant improvement in the feed conversion ratio was also recorded (1.85 compared to 1.45).

These results suggested that dietary supplementation with olive-derived polyphenols can enhance growth while maintaining the fish’s general health and physical welfare.

In addition, genetic analyses showed that fish fed with the polyphenol-based supplement improved the gene expression of biomarkers related to immunity and metabolism.

The researchers particularly noted the reduction in the pro-inflammatory gene interleukin 12 beta expression and an increased expression of the anti-inflammatory gene interleukin 10.

These results tally with previous studies demonstrating that plant protein-based diets lower the expression of various pro-inflammatory markers and other genes linked to immune defense.

In contrast, animal protein-based diets, such as fish meal, lead to an increase in gene expression related to inflammatory mediators tied to regulating inflammation and activating the natural immune response to infection.

The authors note that the European Union generates approximately 88 million metric tons of annual food waste at an estimated cost of €143 billion, with the majority originating from the food industry rather than consumers.

This category of waste material is responsible for eight to ten percent of global emissions and about six percent of the E.U.‘s greenhouse gas emissions, pollution and waste production.

Therefore, they sought to apply the circular bio-economy and sustainable farming concepts to aquaculture.

Extensive research has shown the beneficial effects of fish consumption due to their nutritional profile, which is high in protein, polyunsaturated fatty acids such as omega‑3, and vitamins such as B2 and B6. Fish is an integral part of the Mediterranean diet and other diets associated with health and longevity.

Aquaculture has been mooted as a sustainable means of fish production. It is often contrasted favorably with traditional fishing and its associated environmental impacts, particularly over-fishing, food-web disruption and bycatch – the incidental capture of non-target species such as dolphins, marine turtles and seabirds.

Recent studies, however, have raised concerns about potentially harmful practices within the industry.

Some of the main factors cited are the composition, source and performance of feeds. Improving the sustainability of this aspect is therefore seen as key to improving the sustainability of the industry as a whole.

• Nature Communications

According to a paper published in the scientific journal Medicina, two bioactive polyphenols, oleacein and oleocanthal, have been shown to reduce some of the most visible signs of aging in older adults.

While extra virgin olive oil contains dozens of phenols, the researchers focused on these two compounds due to their promising effects on skin health, especially in treating non-melanoma skin cancers and promoting wound healing.

Additionally, these two phenols are recognized for their potent anti-inflammatory properties, as supported by a growing number of studies.

The study applied both compounds in a skincare solution to 55 women and 15 men over one month. The participants were divided into subgroups based on age and skin morphotypes.

In randomized, single-blind studies, a common clinical trial method, only the researchers know which treatment is given to the participants.

At the beginning of the study, detailed data were collected on the participants, including their age, weight, height, skin phototype, medical history, medication use and smoking and alcohol habits.

Participants were instructed to apply a one percent serum containing oleocanthal and oleacein twice daily for 30 days. Skin data were collected at the start of the study, after 15 days, and at the end of the month.

The researchers used the VISIA Skin Analysis System, a widely used platform for assessing skin treatments, to evaluate the improvement in skin aging. This system captures information such as total wrinkle area and wrinkle intensity.

Deep and superficial wrinkles were assessed at the study’s start, mid-point and conclusion.

The results revealed an average 23 percent reduction in wrinkle count across all participants.

Both men and women showed cumulative effects from the serum, with researchers observing that the treatment’s efficacy increased throughout the study.

According to the study authors, the effectiveness of the two compounds “aligns with broader research on the skin health benefits of polyphenols, including their ability to penetrate epidermal barriers and interact with cellular receptors.”

“Polyphenols have been observed to improve the structural organization of the dermis, which is crucial for its barrier function, and to increase dermal thickness and hydration levels, which are essential for maintaining healthy, well-functioning skin,” the researchers added.

However, men and women experienced different outcomes.

Specifically, younger men aged 20 to 44 saw a 52 percent reduction in wrinkles, while older men had a 47 percent reduction.

For women aged 45 to 79, wrinkle count decreased by 34 percent, while younger women experienced a 26 percent reduction.

“Our study demonstrates that oleocanthal and oleacein significantly reduce wrinkle count in both men and women, especially in those aged 45 through 79,” the authors wrote.

They further noted some limitations, including the short duration of the trial, the lack of long-term follow-up and the absence of a placebo control group.

“The data collected at three distinct time intervals show a consistent trend of wrinkle reduction. However, the overall findings support the use of extra virgin olive oil-derived polyphenols in anti-aging skincare formulations,” they wrote, suggesting the need for more extensive and detailed studies.

Olive oil has been used for skincare for thousands of years. Today, a growing body of scientific research supports the importance of using high-quality olive oil in skincare.

This research explores the use of extra virgin olive oil in dedicated skincare products and the long-term anti-aging effects of a diet rich in extra virgin olive oil, such as the Mediterranean diet.

The most common cardiac arrhythmia, atrial fibrillation, is characterized by rapid and irregular beating of the heart’s atrial chambers. The condition can contribute to or be a precursor of a wide range of complications, from chest pain and fainting to heart failure and stroke.

Despite advances in medical procedures and pharmaceutical treatments, the incidence of atrial fibrillation has been increasing worldwide, particularly in the so-called developed world.

For example, a major cohort study estimated a three percent increase in the United States annually from 2006 to 2018. This has led to a resurgence in interest in lifestyle management, of which diet is a significant aspect.

The researchers from the cardiology division of Baylor Scott & White Health Hospital, Texas, used a narrative synthesis approach to explore the impact of dietary interventions on atrial fibrillation and to assess the role that individual components of those interventions play.

The study found that the two dietary patterns most commonly associated with reduced incidences and improved outcomes were the Mediterranean and DASH diets.

Although the latter was linked to improved cardiovascular outcomes and decreased mortality, the researchers found that once other lifestyle factors were considered, there was no demonstrable effect on the specific incidence, recurrence or progression of atrial fibrillation.

On the other hand, the Mediterranean diet served as “a robust preventative strategy against the development of atrial fibrillation.”

In exploring the potential mechanisms behind this effect, the researchers posited several possible factors.

The first is the Mediterranean diet’s high percentage of fruits, vegetables and extra virgin olive oil. All three food groups provide antioxidants and polyphenols, which have proven anti-inflammatory and cardioprotective effects.

Oleuropein, for example, has demonstrated a capacity to significantly reduce blood pressure, aligning with the traditional use of olive leaf in treating hypertension.

Studies discussed in the paper also provide evidence for the anti-thrombotic and anti-arrhythmic properties of oleocanthal and hydroxytyrosol, compounds found almost exclusively in extra virgin olive oil.

These compounds have been shown to improve endothelial function and reduce platelet aggregation, thereby lowering the risk of events such as stroke in patients with atrial fibrillation.

The importance of olive-based compounds was further supported by a secondary analysis in 2014 of the PREDIMED trial, which revealed significant atrial fibrillation protection from a Mediterranean diet supplemented with extra virgin olive oil.

The researchers cited that analysis, which showed a 38 percent reduction in relative atrial fibrillation risk compared to other diets.

While the examined evidence strongly supported the role of antioxidants and polyphenols, particularly regarding direct links to reduced atrial fibrillation incidence, the researchers stress that the mechanisms in question remain relatively unexplored.

They conclude, therefore, that while each component warrants extensive further research, dietary interventions such as the Mediterranean diet should be considered holistically in the context of disease prevention.

This conclusion is based on the growing evidence showing that the Mediterranean diet is linked to significantly reducing cardiovascular events and diabetes mellitus, improved blood pressure, insulin resistance, lipid profiles and triglycerides, and significantly lower obesity rates.

• American Heart Journal

These extracts could provide more effective anti-inflammatory results than well-known drugs such as Ibuprofen. While phenol extraction has been typically expensive, the new extracts can be produced at a fraction of the cost.

One reason phenol extraction is so costly is the required chemicals. The new process eliminates the need for these chemicals, relying entirely on water as a solvent.

Additionally, this water-based process produces no chemical waste and does not affect the edibility of the processed olive oil.

“We have developed a water-based, eco-friendly and biocompatible methodology,” said Antonio Francioso, co-author of the study and researcher at the University of Teramo’s Bioscience and Technology for Food, Agriculture and Environment Department.

“Oleocanthal and oleacein are natural, edible products formed during olive oil production. They are derived from plant precursors, ligstroside and oleuropein,” he added. “They are especially notable for their anti-inflammatory and antioxidant effects.”

The researchers developed a method to synthesize two oleocanthal and oleacein derivatives, thiocanthal and thiocanthol.

They also explored how oleocanthal, oleacin and their new derivatives could inhibit cyclooxygenase activity. Cyclooxygenase inhibitors, like Ibuprofen, are commonly used to reduce inflammation.

“We confirmed existing data by using Ibuprofen as the gold standard in our tests,” said Luciana Mosca, co-author of the study and researcher at Sapienza University’s biochemical sciences department.

“Oleocanthal, oleacein and the new molecules demonstrated significantly stronger activity than Ibuprofen as cyclooxygenase inhibitors,” she added.

The new molecules differ from oleocanthal and oleacein due to a process known as sulfonation, which could potentially make them far more effective for medical applications.

“Oleocanthal and oleacin, though well-studied, have shown great activity in vitro and in cellular systems,” Mosca said. “However, they face a significant pharmacokinetic issue: they are unstable molecules.”

When oleocanthal and oleacein are ingested, they degrade rapidly as the body identifies the compounds as potentially harmful and employs various biological systems, including enzymes, to break them down.

“The extreme reactivity of these molecules is due to their chemical structure. By using this sulfonation reaction, we can make them much less reactive,” Mosca said. “That’s why we believe that in vivo, these molecules could demonstrate greater pharmacological activity.”

“However, this still needs to be confirmed from a scientific perspective,” she added. “We have early evidence, and we’re continuing to conduct tests. There’s more to come in the next chapter.”

Although dozens of phenols are present in extra virgin olive oils, not all extra virgin olive oil contains the same amount and proportion of these compounds. Interestingly, these differences impact the production process of the new extracts.

“It’s important to select cultivars that produce olive oils particularly rich in these two polyphenols, as not all cultivars can yield high amounts of oleocanthal and oleacein in the oil,” said Roberto Mattioli, co-author of the study and researcher at Sapienza University’s biochemical sciences department.

For this reason, the researchers focused their initial study on Coratina, an Apulian cultivar known for producing extra virgin olive oil in which 70 to 80 percent of the phenols are oleocanthal and oleacein.

“Even with such rich cultivars, traditional extraction methods rely on lengthy processes involving organic solvents, which must be removed afterward, posing risks to both the environment and workers,” Mattioli said.

Mattioli and his colleagues said they had developed a method using biocompatible molecules instead of organic solvents to obtain highly concentrated extracts, reaching about 50 milligrams of polyphenols per milliliter.

“These molecules can be safely ingested, potentially administered directly to animals, or used in vitro on tissues or cells in culture because they are entirely biocompatible,” he said. “With such high concentrations, the substances can be appropriately diluted in various culture media and administered directly, without further purification steps or solvent evaporation.”

“Currently, five milligrams of oleocanthal can cost €250, making it unsustainable for large-scale production,” Francioso added.

According to the researchers, the new process might turn the tables.

“Starting with particularly rich oils, we use an extremely economical method… to concentrate polyphenols by a factor of 100 in a biological and lipid solvent,” said Rodolfo Federico, co-author of the study and co-founder of the startup Active-Italia.

“For the first time, we have raw materials that can be used as health-promoting agents. Until now, no supplements containing oleocanthal and oleacein have existed,” he added, “only their precursors.”

He believes extracts of these two molecules will have far-reaching benefits beyond the proven anti-inflammatory properties attributed to their cyclooxygenase-inhibiting behavior.

“In vivo evidence from clinical studies in patients shows that olive oil with high oleocanthal and oleacein content inhibits the synthesis of pro-inflammatory cytokines,” he said. “The mechanism of action could be much broader, potentially addressing multiple pathologies. It’s truly quite fascinating.”

Hundreds of studies have linked consuming extra virgin olive oil to various health benefits.

In the south of Italy, mills have been working since September 1st and in Andalusia, Spain, the harvest of Gordal table olive variety is already underway.

Meanwhile, the first new oil is already flowing in Slovenia, the small European country sandwiched between Italy and Croatia on the northeastern coast of the Adriatic Sea.

“Last year, we harvested on September 14th, and this year, we moved the date three weeks earlier,” said Danijel Stojković Kukulin, an olive farmer and biochemist.

“We were interested in what kind of oil would be produced from the olives harvested and processed in August, what its characteristics would be and ultimately what the yield would be,” he added.

Stojković is a member of Terra Centuria, a cooperative of young olive growers. Many of them focus on organic cultivation and early harvests.

Stojković’s first extra virgin olive oil of the year, made from the Istarska bjelica variety on August 23rd in the cooperative’s mill, pleasantly surprised everyone. Along with other vital components, the first analysis showed more than 1,500 milligrams of polyphenols per liter.

“This is a concentrate of the olive fruit itself,” Stojković said. “In addition to many polyphenols, the oil is intensely green in color, has a lot of chlorophyll and is extremely spicy.”

Stojković became a professional olive grower about ten years ago when he inherited a grove with about 50 trees from his grandfather Oreste in Čežarji, near Koper, the largest city in coastal Slovenia.

He later planted 300 Istarska bjelica, Grigan, Coratina, Leccino and Storta olive trees on a neighboring hill, which he plans to cultivate organically. Stojković also plans to add 150 trees of Greek varieties.

After receiving a bachelor’s degree in biochemistry, Stojković earned a doctorate in molecular genetics and biotechnology.

He has tried new things in olive farming and milling, from organic farming techniques and cultivation of lesser-known olive varieties to innovative technological approaches in the mill, which give greater added value to the oil.

Stojković is especially interested in polyphenols, first learning that green olives contain the highest concentration of polyphenols by reading about the growing skills of the ancient Romans and Greeks. In ancient Rome, they knew five basic categories.

“The most expensive, often celebrated as the oil of the gods, was produced from perfectly green olives, harvested usually from the end of August to the end of September,” Stojković said. “They called that oil: Oleum aestivum (summer oil), Oleum acerbum, Oleum omphacium or Oleum ex albis ulivis. This oil was mostly used for medical and cosmetic purposes.”

Modern scientific methods have since confirmed what the Romans described, identifying oleocanthal, oleuropein, oleacein, hydroxytyrosol, tyrosol and other bioactive compounds that give extra virgin olive oil unique flavors and enhanced health benefits.

Extra virgin olive oil’s polyphenols have been associated with preventing and mitigating some of the most common chronic diseases, including cardiovascular disease, cancer, dementia and diabetes.

The Terra Centuria cooperative has been studying and experimenting with different harvesting, milling, and storage methods for several years. “The goal is for our oil to reach more than 5,000 milligrams of polyphenols per liter,” Stojković said.

He explained that this year, among other things, they kept the olives in a cold chamber during the harvest and used dry ice during milling.

“Decreasing the temperature, especially in aromatic varieties, greatly increases the creation of fresh and pleasant aromas while at the same time reducing the extraction of polyphenols,” Stojković said. “ It is important where we reduce the temperature, but we are still working to determine by how much and for how long.”

In the final stage, every detail in the oil mill affects the amount and composition of polyphenols in olive oil. Even a small blade speed or mixing time change can significantly change the oil’s properties.

“This year, we also confirmed the hypothesis that technology in the oil mill can influence the composition of polyphenols in olive oil,” Stojkovič said. “In previous years, for example, we had about ten percent oleocanthal, and this year, we managed to get more than 60 percent of all polyphenols.”

Over the past five years, the quality of his high-polyphenol extra virgin olive oils has been corroborated at Aristoleo, a Greek competition specializing in high-polyphenol olive oil.

“I sent the first sample of my oil to that competition five years ago and won the highest prize,” Stojkovič said. “It was a confirmation that I am on the right path.”

Along with the health benefits and awards, Stojkovič’s extra virgin olive oil is increasingly valued in haute gastronomy. Chef Jérôme Banctel uses it at Le Gabriel restaurant in Paris, which has 3 Michelin stars.

With his QQLYN brand, Stojkovič intends to enter the 2025 NYIOOC World Olive Oil Competition, the world’s most prestigious olive oil quality quality contest.

He hopes an award at the NYIOOC will help him establish a partnership with a large American company specializing in distributing high-phenolic olive oils.

Despite the additional cost, Stojkovič believes demand for high-polyphenol extra virgin olive oils will continue to rise in the United States.

“The cost of producing extra virgin olive oil from green olives is double, maybe even triple [that of ripe olives],” he said. “Oil yield is lower. For example, Istarska bjelica, one of the earlier varieties we produced this year’s first oil, had somewhere between eight and ten percent oil yield.”

“In September, we will pick all other varieties as well,” Stojkovič added. “Oil yield will be slightly higher. However, when we calculated the production costs of this first oil, they were between €40 and €50 per liter, so the final price corresponds to that.”

While some high-phenolic extra virgin olive oils retail for €150 to €500 per liter, Stojkovič said his prices will be lower. Still, he is convinced that demand for this market segment will grow, encouraging producers to opt for an early harvest in Slovenia and other countries that cannot compete with Spain, Italy or Greece in quantity. Slovenia produces between 800 and 2,000 tons of olive oil annually.

In a study recently published in Food Chemistry, the scientists detailed a novel extraction method using Natural Deep Eutectic Solvents (NaDES).

The extraction method is crucial because it influences the costs and feasibility of processing olive leaves on a large scale outside the laboratory.

Additionally, it affects the composition of the extracted substances and their potential applications.

The researchers created the NaDES from natural components, combining a glycerol-like liquid substance with choline chloride, a solid salt used in animal feed.

“When you combine these two substances, a new solvent is formed,” said Sónia Sentellas, a researcher in the university’s department of chemical engineering and analytical chemistry and co-author of the study.

“It is a natural substance that does not have toxic impacts on human health,” she told Olive Oil Times.

The first step in producing the extract is to crush the leaves into a fine powder.

“Next, we mix a specific proportion of this powder with the solvent at 80 ºC for two hours and wait for the extract to be produced,” Sentellas said.

“The entire process is similar to making tea,” she added. “The tea leaves are steeped in hot water, which acts as a solvent. After a while, you get colored water with some tea components, and then you separate the leaves from the liquid.”

The researchers found that using NaDES improved extraction efficiency while adhering to environmentally friendly practices.

The study identified several polyphenols in the olive leaf extracts, including hydroxytyrosol, luteolin and oleuropein.

These compounds, also found in extra virgin olive oil, are known for their antioxidant properties and ability to protect cardiovascular and brain health.

While researchers are still exploring potential applications, this extraction process could benefit olive oil production, food packaging and cosmetics.

Additionally, large-scale production of olive leaf extracts could significantly impact the disposal of olive leaves.

Using natural, environmentally friendly, non-toxic solvents broadens the application profile of the obtained substances.

“Some research is directed into understanding how such extracts could be added to olive oil to enhance its healthy profile and taste,” Sentellas said.

Away from olive oil, the researchers are investigating how the extracts might be used in other applications, including extending the shelf life of packaged food products and as an antimicrobial agent.

“Within our research team in Barcelona, we are also working on developing films,” Sentellas said. “Those are based on biodegradable materials and enriched with the polyphenol extract, which opens the opportunity of using these films to extend the shelf life of food and prevent bacterial growth.”

The research team focused on methods to maximize extract purification to broaden the scope of extract applications. Additionally, they are working on recycling the solvent used in the extraction process.

“Recycling the solvent is not only cost-effective and environmentally friendly, but it also makes the entire process more appealing to the industry,” Sentellas said.

Spain is the world’s largest olive oil producer. Significant biomass, including olive leaves, is created during the olive harvest and subsequent pruning. According to some estimates, high-density and super-high-density farms yield 30 tons of olive tree pruning biomass per hectare each year in Spain.

“The goal of our research team is to promote sustainability within the olive oil industry by integrating olive waste into the circular economy,” Sentellas said. “In this research, we aim to recover compounds to create a rich extract with health benefits, adding value to this residue.”

“This aligns with the principles of the circular economy, where waste is minimized and resources are efficiently reused,” she added. “Scaling up the extraction process to an industrial level could transform how the olive oil industry handles its waste.”

The process is currently being tested in a laboratory setting. “The next step is to prepare a pilot plant to see how our lab work can be scaled up to an industrial level,” Sentellas concluded.

Named after German psychiatrist Alois Alzheimer, Alzheimer’s disease is estimated to be the cause of 60 to 80 percent of cases of dementia worldwide and is inevitably fatal.

Marked by cognitive decline and memory loss, the disease affects ten percent of people over the age of 65 and 40 percent over the age of 80.

While deaths from diseases such as stroke and heart disease have been decreasing since 2001, age-standardized dementia mortality rates have risen over the same period.

There are currently more than 55 million Alzheimer’s cases worldwide, and this figure is expected to triple by 2050 as both population and life expectancy increase.

Although numerous experimental treatments for the disease are in development, most research is focused on prevention.

Numerous studies have demonstrated that consuming extra virgin olive oil is linked to improved cognitive function and reduced risk of dementia.

In a recently published cohort study of 92,383 United States adults observed over 28 years, consuming more than seven grams of olive oil per day was associated with a 28 percent lower risk of dementia-related death than never or rarely consuming olive oil.

Unlike those of many previous studies, these results were found to be irrespective of general diet quality.

Polyphenols disrupt plaque accumulation and mitigate inflammation

Polyphenols are a group of natural compounds found in plants, including olives, known for their antioxidant properties.

They have various health benefits, including potential protection against cardiovascular and neurodegenerative diseases.

Extra virgin olive oil is renowned for its rich polyphenol content, which provides most of its health benefits and contributes to its unique flavor and aroma.

Extra virgin olive oil contains 25 polyphenols, including oleocanthal, oleacein, oleuropein and hydroxytyrosol.

Of these, oleocanthal and oleuropein are the most strongly associated with the prevention and mitigation of neurodegenerative diseases such as Alzheimer’s. Current research suggests that there are multiple ways in which this occurs.

Oleuropein aglycone (an oleuropein compound) can induce autophagy, a natural process that eliminates clumps of proteins and damaged organelles (cell components) and stops them from accumulating. Two proteins in particular are associated with this type of accumulation in forms of dementia, such as Alzheimer’s.

Amyloid-beta precursor protein is implicated in various biological functions, from the formation and repair of synapses to hormone regulation. It also forms amyloid-beta, which is toxic to neurons.

Amyloid-beta readily accumulates, forming small clusters called oligomers and eventually accumulating into bulky amyloid plaques.

These accumulations are dangerous for several reasons. They can trigger inflammation through an immune response and may also induce the production of abnormal tau protein.

Tau protein is essential to maintaining the correct structure of neurons. However, when tau protein molecules become damaged, they can detach and form clusters known as neurofibrillary tangles. When this happens, neuron death follows, disrupting the transmission of messages within the brain.

Autophagy deficiency has been discovered in Alzheimer’s patients, as have elevated levels of amyloid oligomers and plaques and neurofibrillary tangles.

Therefore, oleuropein’s ability to induce this process is potentially an important mechanism by which extra virgin olive oil can protect against neurodegeneration.

Amyloid plaque is also present in the brains of older adults who do not develop Alzheimer’s, implying that there is more than one factor at play.

Neuroinflammation, the activation of glial cells, such as microglia and astrocytes, which hold neurons in place and aid their normal function, is a strong candidate.

The activation of these cells causes the production of inflammatory factors such as cytokines and chemokines, which have been observed surrounding plaques and impaired neurons in the brains of Alzheimer’s patients.

Phenolic compounds found in extra virgin olive oil, such as hydroxytyrosol and oleuropein, have demonstrated the ability to impede the translocation of nuclear factor kappa B (NFkB) into the nucleus, leading to diminished production of pro-inflammatory agents and thus curbing neuroinflammation driven by microglia.

Moreover, these compounds have been observed to enhance the secretion of anti-inflammatory cytokines while suppressing the production of pro-inflammatory cytokines, presenting a multifaceted approach to combating neuroinflammation.

MUFAs linked with better brain health via the cardiovascular system

In addition to its high polyphenol content, olive oil is rich in monounsaturated fatty acids (MUFAs).

The famous Seven Countries Study discovered that different fats could have very different effects on health. The study revealed that people in Greece and other parts of the Mediterranean enjoyed a low rate of heart disease despite a high-fat diet.

The researchers concluded that this was because the primary fats in their diet were not the saturated animal fats common in countries with higher rates of heart disease but the monounsaturated fats of olive oil.

Strong evidence exists linking cardiovascular disease and Alzheimer’s, so reducing the former is one of many strategies seen as essential to prevention.

The replacement of saturated fats with monounsaturated fatty acids such as oleic acid has a proven track record in this area. Oleic acid is the major component of olive oil, constituting 70 to 80 percent.

In addition to helping to regulate immune function, research has shown that when it is used to replace dietary saturated fat, monounsaturated fat reduces the risks of cardiovascular disease by decreasing levels of blood lipids such as cholesterol.

It has also been demonstrated that increasing and decreasing the latter in human blood serum improves the HDL (high‐density lipoprotein) to LDL (low‐density lipoprotein) ratio.

One significant way in which cardiovascular disease may contribute to the development of dementia is through the deterioration of the blood-brain barrier. This barrier refers to the specialized properties of the central nervous system’s vascular system that control the exchange of ions, molecules and cells between the blood and the brain.

When it becomes dysfunctional, the blood-brain barrier can allow toxic molecules into the brain and impair the elimination of toxic substances such as amyloid-beta and abnormal tau proteins.

This can lead to increased neuroinflammation and oxidative damage, which has also been linked to Alzheimer’s.

Research has found that the regular consumption of extra virgin olive oil reduces the permeability of the blood-brain barrier in the hippocampi and surrounding area, thus helping to restore normal function.

EVOO and the Mediterranean diet

Multiple studies have concluded that adherence to the Mediterranean diet corresponds to a reduced risk of dementia, including Alzheimer’s disease.

A 2023 cohort study from the United Kingdom Biobank found that the higher an individual’s adherence, the lower their risk of developing dementia. Strikingly, this was found to be true regardless of genetic predisposition.

A separate 2023 U.S. study found that levels of five micronutrients common in the Mediterranean diet were significantly lower in the brains of those who had died with Alzheimer’s disease than those who had died without it.

The study analyzed the brains of 31 donors whose average age at death was 75 and found that the brains of those with the disease had around half the levels of lycopene, retinol, lutein, zeaxanthin and vitamin E.

Although the body only needs these substances in small amounts, they are crucial to maintaining many bodily systems, such as the immune system, the eyes and the skin.

Mediterranean countries are historically among the healthiest countries in the world, recording relatively low rates of cardiovascular diseases and cancer, as well as longer life expectancy.

On the purely dietary front, the Mediterranean diet is based on the daily consumption of fruits, vegetables, legumes, nuts, whole grains and some dairy, with extra virgin olive oil serving as the primary source of fat.

The Spain-based Mediterranean Diet Foundation, one of the most influential organizations dedicated to researching and promoting the Mediterranean diet, defines the diet as a way of life. In the foundation’s view, lifestyle and values form a vital part that can not be separated from the whole.

This is reflected in its Mediterranean diet pyramid. Unlike more familiar food pyramids, the base is built from a combination of exercise, rest, socializing, and cooking on the physical front and a commitment to sustainable, local, seasonal and eco-friendly food choices on the value front.

While more research is needed to determine how the Mediterranean diet helps the body avoid and combat so many diseases, its benefits to human health are already firmly established.

CVDs encompass a range of conditions affecting the heart and blood vessels. The most prevalent among these are coronary heart disease, rheumatic heart disease and cerebrovascular disease.

The New York State Department of Health recently reported that about 695,000 Americans die from heart disease annually, representing one in five deaths in the country. Globally, the World Health Organization estimates that cardiovascular disease accounts for 32 percent of all deaths.

While cardiovascular diseases are triggered by various factors, including genetics, pollution and lifestyle, a growing body of research links daily consumption of extra virgin olive oil, the highest-quality olive oil category, to significantly reducing the risk of developing cardiovascular diseases.

The evidence behind olive oil’s decisive impact

A large-scale trial conducted on thousands of individuals in Spain during the 2010s demonstrated that adherence to the Mediterranean diet and daily consumption of olive oil significantly reduce cardiovascular events in at-risk patients compared to a generic low-fat diet.

The PREDIMED (PREvención con DIeta MEDiterránea) study, published in the New England Journal of Medicine, laid the foundations for further research worldwide.

The Seven Countries Study, conducted since the 1950s across the U.S., Finland, Netherlands, Italy, Greece, Yugoslavia and Japan, also confirmed the critical role of olive oil and the Mediterranean diet in reducing cardiovascular diseases.

This extensive epidemiological study involved 12,000 middle-aged men, revealing that daily consumption of unsaturated fats, such as olive oil, and adherence to the Mediterranean diet significantly lower heart disease risks.

These studies confirmed the significant impact of dietary behavior on cholesterol levels and other conditions related to the development of cardiovascular diseases.

As a result of these studies, hundreds of scientific publications have explored the unique role of olive oil in human health in recent decades.

Olive oil’s beneficial effects are attributed mainly to its high content of monounsaturated fats. The polyphenols found in the highest grade of olive oil, extra virgin olive oil, further enhance these health benefits.

The role of monounsaturated fatty acids (MUFAs)

Oleic acid, a monounsaturated fatty acid (MUFA), is a critical component of olive oil and is credited with many of the significant health benefits associated with its consumption.

“It is important to note that extra virgin olive oil consists of 60 to 83 percent MUFAs,” said Bruno Tuttolomondo, a full professor of internal medicine at the University of Palermo and director of the internal medicine with stroke care unit at Policlinico Hospital in Palermo.

“The remaining composition includes small percentages of saturated fatty acids, such as palmitic acid and stearic acid,” he added. “Along with polyunsaturated fats, monounsaturated fats are considered ‘good fats.’”

Tuttolomondo said research indicates that a high percentage of MUFAs play a crucial role in preventing cardiovascular diseases.

“This is because MUFAs influence cholesterol and LDL levels, reduce LDL oxidation and affect the composition of atherosclerotic plaques, thereby exerting a cardioprotective role,” he said.

LDL stands for a low-density combination of fat and protein. It is a type of cholesterol that can accumulate in the bloodstream and form plaques in the arteries, leading to atherosclerosis.

“MUFAs are not the only important components of extra virgin olive oil, but they are the most abundant,” Tuttolomondo said. “This alone qualifies extra virgin olive oil as one of the ‘good fats.’”

Polyphenols are critical to CVD risk reduction

Polyphenols are a diverse group of hundreds of substances found in many foods.

Extra virgin olive oil contains dozens of these polyphenols, which are rare and especially valuable due to their high bioavailability.

This means that, once consumed, they reach areas of the body where they can exert their effects, including potent antioxidant and anti-inflammatory properties.

“Polyphenols certainly play a role in cardiovascular health and are the subject of significant research due to their cardioprotective actions,” Tuttolomondo said.

One of the most researched polyphenols for cholesterol and cardiovascular diseases is oleuropein.

“Many researchers, including [Francesco] Violi’s team at La Sapienza University in Rome, are investigating oleuropein,” Tuttolomondo said. “They discovered that oleuropein helps stabilize lipid plaques and reduce LDL oxidation.”

“They also found that it modulates the impact of diabetes on vascular and cardiovascular health,” he added.

EVOO might enhance diabetes prevention

According to the World Health Organization, 422 million people have diabetes globally. Research has shown that extra virgin olive oil and adherence to the Mediterranean diet can significantly lower the risk of developing the disease.

Diabetes is linked to cardiovascular diseases because it can lead to excessive sugar in the blood, which can damage the blood vessels that supply the heart. This damage can reduce the supply of oxygen and nutrients to the heart, significantly increasing the risk of heart disease.

“For some time, the impact of extra virgin olive oil on diabetes was evaluated indirectly,” Tuttolomondo said. “In numerous studies, including those conducted by my research group, we analyzed adherence to the Mediterranean diet, which considers extra virgin olive oil the primary fat. It is well known that adherence to the Mediterranean diet results in a lower incidence of diabetes.”

Further research has built on these findings. “We now know that extra virgin olive oil and phenols such as oleuropein have effects similar to some compounds used in diabetes therapies, as they increase insulin sensitivity,” Tuttolomondo said.

“We now have strong evidence of the preventive role and regulation of glycemic levels by daily and regular consumption of extra virgin olive oil, especially when consumed for many years,” he added.

“While you cannot expect to lower blood sugar by simply eating a salad with extra virgin olive oil, daily, familial and traditional consumption of extra virgin olive oil has proven effective in reducing the prevalence of diabetes,” he noted.

Olive oil is the healthier, tastier fat choice

“One of the unique qualities of extra virgin olive oil is its flavor. In addition to its wide-ranging health benefits, it also offers an exquisite taste,” Tuttolomondo said. “No other cooking fat combines favorable organoleptic properties with beneficial nutrients like extra virgin olive oil. It is a small miracle, combining health and taste.”

However, he emphasized that other fats can also benefit human health.

“Consider polyunsaturated fats like Omega‑3 and Omega‑6, which have been shown to play a role in cardiovascular disease prevention. Still, none of them compare to extra virgin olive oil in daily use,” Tuttolomondo said. “Extra virgin olive oil is the centerpiece of every lunch and dinner for those who follow the Mediterranean diet.”

“When we talk about Omega‑3 and Omega‑6, we think of fats from blue fish or almond extracts. While some people eat five almonds for lunch, it’s impractical to base a diet on almonds,” he added.

Healthy fats like pumpkin seed or flaxseed oil have beneficial profiles but do not offer the same organoleptic properties as extra virgin olive oil.

“They are beneficial fats, but consider flaxseed oil; it has no flavor, so it cannot motivate people through taste,” Tuttolomondo said. “In my opinion, we need to attract people to prevention by appealing to their sense of taste.”

Meanwhile, avocado oil has been the subject of several studies. “From a palatability standpoint, it is virtually flavorless,” Tuttolomondo said. “It contains a significant amount of polyunsaturated fats, but I don’t think there are enough studies on its polyphenolic content.”

How much extra virgin olive oil should be consumed?

Extra virgin olive oil should be consumed daily to reap its health benefits.

However, not all extra virgin olive oils are the same. While oleuropein and other polyphenols can significantly benefit human health, the amount and type of phenols vary among extra virgin olive oils.

“Polyphenol content depends on factors including cultivar, cultivation area, processing methods, and external temperature,” Tuttolomondo said. “There is a threshold of polyphenol content that characterizes a high-quality extra virgin olive oil.”

“Polyphenols are one of the criteria for evaluating extra virgin olive oil,” he added. To have a significant effect, it should contain no less than 250 to 350 milligrams per kilogram.”

“It has been hypothesized that higher levels of polyphenols correspond to greater cardioprotective effects,” Tuttolomondo continued. “However, we should always remember the key role played by MUFAs, which are the foundation of all extra virgin olive oils.”

While excessive olive oil consumption can lead to excessive calorie intake, researchers have worked to define recommended daily doses of extra virgin olive oil.

“Many studies indicate that 20 grams of extra virgin olive oil can optimize the benefits of the Mediterranean diet,” Tuttolomondo said. “This equates to about one to one and a half tablespoons.”

“However, intervention studies have evaluated up to four tablespoons per day for cardiovascular effects,” he added. “Considering weight regulation and overall caloric intake, I would say that the more extra virgin olive oil we consume, the better.”

• World Health Organization
• New York State Department of Health

The economically damaging olive tree disease is caused by the Colletotrichum fungus. The fungus causes severe rot in olives, leading to significant crop losses.

Olive oil from olives contaminated by fungus has higher acidity and organoleptic defects. It usually falls into the lampante category and is unsuitable for human consumption.

“We analyzed six varieties for two years, carrying out analyses of phenolic compounds and resistance tests to the pathogen,” said Hristofor Miho, a PhD student at the University of Córdoba and first author of the study.

“The results allowed us to observe that resistance was greater in varieties with high phenolic concentrations and specific phenols present in them,” he added.

The researchers selected Empeltre and Frantoio cultivars, known for their resistance to the fungus; Hojiblanca and Picudo, known for their lack of resistance; and Barnea and Picual, considered moderately resistant.

Olives were harvested from the World Olive Germplasm Bank of Córdoba before they began to ripen and at three ripening stages: green, turning and ripe.

Samples were taken to determine the olives’ phenolic profiles, and they were then inoculated using spores of the most common Colletotrichum strain found in Spain and Italy.

While all green olives are immune to the fungus, they accumulate inactive Colletotrichum infections in the form of appressoria, an organ-like structure that penetrates the fruit.

“This infection remains latent during fruit development until ripening, resulting in pathogen reactivation and disease development,” the researchers wrote. “Subsequently, olive fruit susceptibility to the pathogen increases during ripening, while in parallel, there is a decrease in total phenolic compounds.”

The researchers also isolated seven standard phenolic compounds to test their antifungal activity: hydroxytyrosol, tyrosol, oleuropein, oleuropein aglycone, oleacein, oleocanthal and hydroxytyrosol 4‑O-glucoside.

“Oleocanthal exhibited the highest inhibitory activity, followed by oleacein, oleuropein aglycone, hydroxytyrosol and tyrosol,” the researchers wrote.

Oleuropein, ligstroside (the precursor of oleocanthal) and their derivatives, including oleacein, were the most critical compounds inhibiting spore germination.

The compounds are predominant in all green fruits regardless of cultivar and represent more than 90 percent of total phenols during ripening of the main resistant cultivars.

Meanwhile, susceptible cultivars converted oleuropein, oleacein and oleocanthal into hydroxytyrosol-4-O-glucoside as they ripened, which reduced anthracnose tolerance.

“Overall, resistant cultivars induced the synthesis of aldehydic and demethylated forms of phenols [oleuropein, oleocanthal and oleacein], which highly inhibited fungal spore germination,” the researchers wrote. “In contrast, susceptible cultivars promoted the synthesis of hydroxytyrosol 4‑O-glucoside during ripening, a compound with no antifungal effect.”

They further found that a total phenolic concentration of 50,000 milligrams per kilogram in all samples of developing olives across cultivars completely inhibited spore germination.

The researchers observed that cultivars susceptible to the fungus experienced a 73 percent decline in phenolic compounds during ripening, while resistant cultivars experienced a 28 percent decline.

“The sharp phenolic reduction of the susceptible cultivars caused the complete reduction of the antifungal activity,” they wrote. “Interestingly, the lesser phenolic decrease of the resistant cultivars did not reduce the inhibitory effect of spore germination.”

Juan Moral, who oversaw the research, said the study would help policymakers and farmers select new varieties to plant and inform researchers about what varieties to crossbreed for more resistant hybrids.

“Knowing how the phenolic cascades [changes in the phenolic compounds] behave in the different varieties will allow us to better select, based on scientific criteria, the parents that should be used so that the following generations of olive trees are resistant to this disease,” he concluded.

• University of Córdoba
• Food Chemistry

The researchers found that adherence to the Mediterranean diet “is linked to the prevention of several metabolic and chronic degenerative pathological processes, including oral diseases” and that the diet “may represent a potential player in the link between oral microbiome and oral diseases.”

The oral microbiome is the second largest and most diverse microbiome after the gut. Comprising approximately 700 species of microorganisms, it is a complex system whose equilibrium is vulnerable to changes in composition.

This system includes bacteria, fungi, viruses, archaea (single-celled organisms such as methanogens) and protozoa (single-celled organisms such as Entamoeba gingivalis).

According to the United States Centers for Disease Control (CDC), there is a strong correlation between oral disease, especially periodontitis, and chronic systemic diseases.

The organization references several studies reporting that people with periodontitis (inflammatory gum disease) are at higher risk of ischemic or hemorrhagic stroke.

The CDC has also found that tooth loss is another significant risk factor for stroke, and periodontal disease significantly increases the risk of chronic obstructive pulmonary disease.

The World Health Organization further notes that poor oral health is a regular cause of pneumonia in older adults.

The authors note that the oral cavity serves as a reservoir of Staphylococcus aureus, a bacterium that, while ordinarily harmless, can become an opportunistic pathogen causing respiratory and sinus infections.

It is also a leading cause of death among antimicrobial- and antibiotic-resistant pathogen strains such as MRSA, a strain of Staphylococcus aureus.

Research has shown that polyphenols have antimicrobial effects on oral pathogens such as Staphylococcus aureus and Porphyromonas gingivalis, a bacterium linked to numerous diseases, including periodontitis, Alzheimer’s disease and rheumatoid arthritis.

Among patients usually prone to severe periodontitis, adherence to the Mediterranean diet correlated positively with healthier oral habits, including increased tooth count and improved dental plaque removal.

The Mediterranean diet contains numerous elements rich in polyphenols: extra virgin olive oil, which contains oleocanthal, oleuropein and hydroxytyrosol; nuts, which contain proanthocyanidins; fruits, vegetables, red wine and herbs, which contain compounds such as naringenin, apigenin and kaempferol; and many others.

The Mediterranean diet is also rich in fiber, which has been shown to promote oral eubiosis, a state of equilibrium in which beneficial microbial species dominate.

The authors reference three studies in particular when discussing evidence supporting the positive effects of the Mediterranean diet on patients with periodontal inflammation compared to the Western-type diet.

The first, published in 2022, demonstrated a significant decrease in periodontal bleeding and surface inflammation in periodontal inflammatory patients after following the Mediterranean diet for six months.

These findings contrast notably with studies from 2005 and 2019, which showed an increased gingival inflammatory response in people following a Western-type diet characterized by the high consumption of refined grains and sugars.

The researchers concluded the review article by emphasizing the need to study further the link between adherence to the Mediterranean diet, oral diseases and the oral microbiome.

They also called on dentists to be more proactive in disseminating information about how diet impacts oral health.

“The dentist plays a fundamental role in promoting and disseminating the correct dietary habits based on healthy food choices among the population that, together with lifestyle, may significantly improve their general and oral health status,” they concluded.