- A diet rich in ultra-processed foods is associated with the development of multiple chronic conditions, according to a new study.
- Particularly likely to lead to concurrent cancers, diabetes, and heart problems are animal-based ultra-processed foods and artificially and sugar-sweetened drinks.
- Although this study found no such link between ultra-processed foods such as breads, cereals, or plant-based alternatives, experts caution against their overconsumption.
- An issue with identifying ultra-processed foods is that they are typically categorized according to their degree of processing, with less emphasis on nutritional value.
The consumption of ultraprocessed foods has been linked to various individual chronic diseases such as
The study finds that there is a 9% increase in the likelihood of developing cardiovascular and cardiometabolic comorbidities for those whose diet consists of a significant amount of ultra-processed foods.
The greatest increase in risk, according to the study, was for animal-based products and artificially and sugar-sweetened beverages.
The researchers found no similar association between ultra-processed breads and cereals, plant-based alternatives, and comorbidities.
The study is an analysis of data from the European Prospective Investigation into Cancer and Nutrition (EPIC). This is an ongoing prospective cohort study of associations between cancer and other diseases, and lifestyle, diet, genetic, and environmental risk factors.
For the new study, the researchers looked at data from 266,666 participants. The foods they ate were ranked based on their level of processing according to the NOVA index. There was a median 11.2 years of follow-up to track the development of chronic diseases.
The study is published in
There is no universal agreement on exactly what attributes define a problematically processed food. This is largely because most modern foods, unless sourced directly from the location in which they are grown, involve some measure of processing.
Processed foods may include such healthy food items as tofu, simple bread, canned tuna or beans, and cheese. However, it is ultra-processed foods, or UPFs, that are of greatest concern.
The standard embraced by most researchers is the NOVA index, developed by Carlos Monteiro and colleagues at the Sao Paolo University in Brazil.
The new study’s senior investigator, Dr. Heinz Freisling, scientist in nutrition and metabolism for the World Health Organization, explained how the index works:
“NOVA classifies foods not according to their nutrient profile, but according to their degree of processing into four categories: fresh or minimally processed, culinary ingredients, processed, and ultra-processed.”
Michelle Routhenstein, preventive cardiology dietitian at EntirelyNourished.com, who was not involved in the study, described the final category as “foods that are made exclusively using a combination of industrial processes.”
Since the degree of processing alone does not tell the entire story — ingredients matter as well — there remains room for personal opinions on the matter.
For Dr. Freisling, “[u]ltra-processed foods are foods that cannot be prepared at home because of a lack of both machinery needed for preparation, and ingredients that are characteristic for ultraprocessing. Examples of such ingredients are colorants, artificial sweeteners, food preservatives, and more.”
Why might consuming ultra-processed foods result in comorbidities? “This is currently a hot topic of research because it is not yet clear why ultra-processed foods show this strong link with a wide range of conditions,” said Dr. Freisling.
He hypothesized that perhaps it has to do with the ready availability and lower cost of such foods to the consumer. Designed for flavor — and imperishability — people tend to over eat them.
“For example, a simple boiled corn cob is no competition to a bag of tortilla chips,” Dr. Freisling said.
He also suggested additives, including artificial sweeteners, may play a role.
“The pure lack of dietary fiber and the modified food matrix — the natural matrix or shape of a food at a microscopic level — could play an important role,” he added.
Routhenstein noted that processing methods themselves may also be responsible. She said that ultraprocessing methods create byproducts within the food that can promote disease.
“For example, advanced glycation end products (AGE) are formed as a byproduct of certain food productions, and it can lead to inflammation and oxidative stress, contributing negatively to a wide range of health conditions,” pointed out Routhenstein.
“AGE levels are highest per gram in ultra-processed foods that utilize dry heat, such as crackers, chips, and cookies,” she further noted.
Although the study found no association between ultra-processed breads and cereals and plant-based alternatives, Dr. Freisling does not believe that means they should be considered a worthwhile component in one’s diet.
“I do remain concerned because people consuming a diet with a high proportion of ultra-processed foods usually consume these foods across the board,” he said.
Furthermore, while the study is concerned with comorbidities, such foods have been linked to individual chronic diseases in previous studies.
Routhenstein offered several easily prepared foods that can take the place of ultra-processed foods in one’s diet.
“An easy swap you can make is changing fruit-flavored yogurts to making your own yogurt and fruit bowl,” said Routhenstein.
Another yogurt-related improvement would be to replace whey protein powder that contains emulsifiers, flavor enhancers, and isolates with ¾ cup of unflavored/unsweetened Greek yogurt.
Routhenstein provided a few other tips, such as exchanging ultra-processed meat like bacon for a homemade tempeh and mushroom version.
A plant-based recipe“Adding coconut aminos, apple cider vinegar, and a touch of maple syrup with a dash of smoked paprika to sliced tempeh and shiitake mushrooms is a way you can cut back on processed meats and add a nutrient-dense protein that is good for your heart, gut, and bones. This could also help decrease oxidative stress, the opposite of what ultraprocessed foods do!”
— Michelle Routhenstein
“We showed that a risk factor — here a high consumption of ultra-processed foods — is not only linked to a higher risk of one severe disease, e.g., diabetes, but can increase the risk of [experiencing] a combination of diseases, known as multimorbidity,” said Dr. Freisling.
“Second,” he said, “I do think that it is important to communicate to the public that certain subgroups of ultraprocessed foods should be preferred over others. For example, plant-based vs. animal-based products.”
Routhenstein agreed with this second point, saying, “This sheds light on the need to assess nutrient value like fiber in offsetting the detrimental effects of ultra-processed foods as defined by the NOVA classification scale.”