Negative Health Impacts of Ultra-Processed Foods Go Beyond Their Nutritional Profiles, Researchers Say

Summary

Research sug­gests that the impact of ultra-processed food con­sump­tion on human health is sig­nif­i­cant and not solely based on nutri­tional qual­i­ties. New stud­ies indi­cate that the mor­tal­ity risks asso­ci­ated with high con­sump­tion of ultra-processed foods are not explained by the foods’ nutri­tional pro­file, urg­ing peo­ple to con­sider the level of pro­cess­ing in the foods they con­sume in order to improve pub­lic health.

The impact of ultra-processed food con­sump­tion on human health may be more sig­nif­i­cant than the food’s nutri­tional qual­i­ties.

According to new research in Italy, food rat­ings cur­rently used for pack­aged food labels may miss the point by mainly focus­ing on the nutri­tional pro­file of processed foods.

The research paper pub­lished by the Journal of the British Medical Association (BMJ) found that sig­nif­i­cant ultra-processed food con­sump­tion leads to higher mor­tal­ity risks by sev­eral causes. However, the nutri­tional pro­file of such food does not impact these risks.

The same edi­tion of the BMJ also fea­tured American research demon­strat­ing a link between high con­sump­tion of ultra-processed food and col­orec­tal can­cer, with sig­nif­i­cant dif­fer­ences in the impact between men and women.

Investigating the results of their 15-year study on more than 20,000 indi­vid­u­als, the Italian researchers tested the effects of con­sum­ing ultra-processed food, clas­si­fied as such by NOVA rat­ings, while also con­sid­er­ing their nutri­tional clas­si­fi­ca­tion from the Food Standards Agency Nutrient Profiling System (FSAm-NPS).

NOVA was devel­oped by researchers at the University of São Paulo in Brazil. According to a 2019 United Nations Food and Agricultural Organization paper, NOVA def­i­n­i­tions of ultra-processed foods are the most applied in sci­en­tific lit­er­a­ture.

FSAm-NPS, on the other hand, is cur­rently used to rate foods by rel­e­vant front-of-pack-label­ing sys­tems, such as the French-born Nutri-Score.

“We felt the need to see if Nutri-Score could really help improve pub­lic health, as the European Commission is cur­rently con­sid­er­ing its intro­duc­tion as an E.U.-wide manda­tory food rat­ing sys­tem,” Marialaura Bonaccio, senior epi­demi­ol­o­gist at the Italian Mediterranean Neurologic Institute and co-author of the study, told Olive Oil Times.

“In the last 10 years, research has gone beyond focus­ing on the sole nutri­tional com­po­si­tion of foods,” she added. ​“Thanks to the work of Carlos Monteiro and oth­ers, the research has begun focus­ing on how food is trans­formed and manip­u­lated.”

According to the researchers, both FSAm-NPS and NOVA reach their food rat­ing goals when indi­vid­u­ally applied to foods. Results change, though, when the two indexes are jointly con­sid­ered.

“Both sys­tems cor­rectly pre­dict health risks,” Bonaccio said. ​“If you con­stantly choose foods rated as inad­e­quate by Nutri-Score, you expose your­self to greater risks of incur­ring rel­e­vant dis­eases. The same goes for NOVA, which is also asso­ci­ated with coro­nary heart dis­ease risk.”

“When they are jointly con­sid­ered, though, the risks asso­ci­ated with Nutri-Score are reduced by the NOVA sys­tem, and that tells us we are not see­ing the impact of a nutri­ent-poor diet but the impact of ultra-processed foods,” she added. ​“More than 80 per­cent of foods Nutri-Score rates as poor qual­ity foods are ultra-processed.”

In the study, the authors wrote that ​“a sig­nif­i­cant pro­por­tion of the higher mor­tal­ity risk asso­ci­ated with an ele­vated intake of nutri­ent-poor foods was explained by a high degree of food pro­cess­ing. In con­trast, the rela­tion between a high ultra-processed food intake and mor­tal­ity was not explained by the poor qual­ity of these foods.”

The NOVA sys­tem typ­i­cally defines ultra-processed food as food hav­ing five or more ingre­di­ents not usu­ally found in a house­hold. Those sub­stances, such as addi­tives and enhancers, are part of ultra-pro­cess­ing meth­ods as they derive from the fur­ther pro­cess­ing of food com­po­nents.

“The ultra-process def­i­n­i­tion is cru­cial because it is not uni­vo­cal. It is mostly com­mon sense,” Bonaccio said. ​“If I bake a pie at home, I might use many sim­ple ingre­di­ents such as flour, eggs or milk. And the out­come might depend on the cor­rect bal­ance among those ingre­di­ents.”

“But when, on top of that, I use food addi­tives, then the pie starts to become an ultra-processed food,” she added. ​“That is why the def­i­n­i­tion is not totally unam­bigu­ous. For exam­ple, if in a super­mar­ket you see a fruit-based yogurt whose pack­age dis­plays five lines of ingre­di­ents, it might be enough to spot an ultra-processed food.”

The food indus­try com­monly uses addi­tives to give spe­cific col­ors to food and sweeten or pre­serve it. Other addi­tives cover many func­tions, such as enhanc­ing fla­vors, sup­press­ing fungi, inhibit­ing par­tic­u­lar char­ac­ter­is­tics of the food or san­i­tiz­ing the food itself.

“The pro­cess­ing of foods might play a role in health beyond their nutri­tional com­po­si­tion, through a vari­ety of mech­a­nisms trig­gered by non-nutri­tional com­po­nents, such as cos­metic addi­tives, food con­tact mate­ri­als, neo­formed com­pounds, and degra­da­tion of the food matrix,” wrote the researchers.

“The health risks that we have found in our study are related to sig­nif­i­cant con­sump­tion of ultra-processed food,” Bonaccio added. ​“Therefore, the sug­ges­tion here is not to abol­ish that kind of food but to limit its intake. People should stop focus­ing only on the nutri­tional pro­file of food. They need to start explor­ing the degree of pro­cess­ing in the food they buy.”

She rec­om­mends that a suit­able method to limit ultra-processed food is to spend more time in the kitchen and fol­low the advice of food jour­nal­ist and author Michael Pollan not to eat any food your grand­mother would not rec­og­nize as food.

“Your grand­mother would not know what sub­stances like mal­todex­trin are. That means that cook­ing must stay close to the ori­gin of food and away from food manip­u­la­tion as much as pos­si­ble,” Bonaccio said, cit­ing a widely-used ultra-processed car­bo­hy­drate.

In a joint edi­to­r­ial about the two stud­ies pub­lished by the BMJ, Carlos A. Monteiro, a pro­fes­sor of pub­lic health nutri­tion at the University of São Paulo and Geoffrey Cannon, a senior research fel­low, warned that ​“to refor­mu­late ultra-processed foods by meth­ods such as replac­ing sugar with arti­fi­cial sweet­en­ers or fat with mod­i­fied starches and adding extrin­sic fiber, vit­a­mins, and min­er­als, is not a solu­tion.”

“Reformulated ultra-processed foods would be espe­cially trou­ble­some if pro­moted as ​‘pre­mier’ or ​‘healthy’ prod­ucts,” they added. ​“They would remain partly, mainly, or solely for­mu­la­tions of chem­i­cals.”

Following their study, the Italian researchers warned against adopt­ing any food label­ing sys­tem mainly based on the nutri­tional aspects of food.

“Within Nutri-Score, for instance, you could find highly refined and processed foods which achieve a good and appar­ently healthy score,” Bonaccio said. ​“That hap­pens because they might be low in salt, sugar or fats. But that does not mean they are to be con­sid­ered a healthy food.”

An exam­ple of this is arti­fi­cially-sweet­ened sugar-free sodas, which achieve healthy scores, ​“even when they are not food at all, but just a chem­i­cal for­mu­la­tion,” Bonaccio added.

She noted that ultra-processed food intake is grow­ing glob­ally. ​“In the United States and the United Kingdom, the most recent data show that 60 per­cent of the daily calo­ries, on aver­age, come from this kind of food. We are still at 20 per­cent in Italy, but that is the ten­dency here as well.”

While the lat­est American and Italian stud­ies join the grow­ing lit­er­a­ture on the health effects of ultra-processed food con­sump­tion, it remains unclear what the rea­sons are for such neg­a­tive health con­se­quences.

“We must inves­ti­gate the inner mech­a­nism,” Bonaccio said. ​“Being now able to set aside the nutri­tional aspects of poor qual­ity food, we still have to under­stand what trig­gers such harm­ful reac­tions.”

Researchers in many coun­tries are work­ing on sev­eral hypothe­ses, inves­ti­gat­ing the impact of alter­ations to the food matrix or the destruc­tion of phy­to­chem­i­cals and other sub­stances.

Other research is focused on the impact of food sep­a­ra­tion and re-aggre­ga­tion on the micro­biome and insulin response or the expo­sure to plas­tic due to the pack­ag­ing of most prod­ucts.

“Each of those con­di­tions might be a trig­ger for phys­iopatho­log­i­cal processes,” Bonaccio said. ​“We are cur­rently work­ing on the inflam­ma­tory path­way, as these aspects might exert a role in ris­ing inflam­ma­tion lev­els.”

“The Mediterranean diet lights the path,” she con­cluded. ​“The MedDiet is not only fruits, veg­eta­bles, a light intake of wine and olive oil; it is mostly an un-processed food diet. We should always remem­ber that it comes from farm­ers’ tra­di­tion made with raw foods or slightly processed foods and the use of min­i­mal tech­niques.”

• The British Medical Journal
• The British Medical Journal
• The British Medical Journal