Ultra-Processed Foods Linked to Cancer and Early Death
- Two new large research studies found that ultra-processed foods can increase the risk for colorectal cancer, premature death, and heart disease.
- The first study found men who ate in the top fifth of ultra-processed food consumption had a 29% higher risk of developing colorectal cancer.
- The second study found that those who ate nutrient-poor foods and ultra-processed foods had a higher risk of developing chronic disease or premature death, especially from cardiovascular disease.
Eating healthy is essential for feeling your best. But, now, two large research studies are showing just how detrimental eating nutrient-poor foods can be. The studies suggest that eating ultra-processed foods can increase the risk of cancer and even lead to heart disease and premature death.
Specifically, researchers saw a link between ultra-processed foods and cancer in men, and heart disease or premature death for both men and women.
But first, what are ultra-processed foods?
Highly-processed or ultra-processed foods have many added ingredients, like sugar, salt, fat, and artificial ingredients. Examples of ultra-processed foods are frozen meals, soda, cold cuts, and sweets, according to Harvard Health. It’s important to note that almost everything we eat (unless we grow it ourselves) is processed—and processed foods have become integral in helping many make the most of their busy lives. Unprocessed or minimally processed foods are foods in their whole form (like apples, bananas, and spinach) that have vitamins and nutrients when consumed.
Processed foods, on the other hand, are foods that have additional ingredients like added salt, oil, sugar, or other additives, like canned fish, fruits in syrup, or bread. And, as mentioned above, ultra-processed foods take this a bit further with added sugar, salt, fat, and artificial ingredients.
Maya Feller, M.S., R.D., C.D.N., registered dietitian nutritionist and author of the upcoming Eating from Our Roots: 80+ Healthy Home-Cooked Favorites from Cultures Around the World explains that some foods deemed “processed” may vary in their nutritional value. For example, the NOVA nutritional rating system used in the second study considered things like soy milk and protein powder as ultra-processed, but these can be healthy additions to the diet. In the context of the noted studies, researchers looked for a connection between foods considered ultra-processed and unfavorable health outcomes.
What the studies say
The first study published in The British Medical Journal found men who ate a lot of ultra-processed foods and men and women who ate some specific ultra-processed foods were associated with an increased risk of colorectal cancer. Researchers looked at data from over 46,000 men from the Health Professionals Follow-up Study and nearly 160,000 women from two different cohorts of the Nurses’ Health Study. Participants had provided dietary information and had no cancer diagnoses at the beginning of the study.
After 24 to 28 years of following up, researchers found 3,216 cases of colorectal cancer in both men and women. Compared to the men in the lowest fifth of ultra-processed food consumption, men in the highest fifth had a 29% higher risk of developing colorectal cancer. These men were also more likely to be current smokers, have higher body mass indexes, lower consumption of alcohol, lower level of physical activity, and consume a diet lower in dietary fiber, folate, calcium, vitamin D, and whole grains with more fat, added sugar, and processed meats. The association remained the same after researchers considered these factors. Interestingly, researchers did not find a connection between overall ultra-processed food and the risk of colorectal cancer for women. More research is needed to determine why this is.
The study did find that those who had ultra-processed foods that included more ready-to-eat products of meat, poultry, and seafood (like bacon, fish sticks, or hotdogs) and sugar-sweetened beverages among men and ready-to-eat/heat-mixed dishes among women also had an increased risk of colorectal cancer. Researchers found that the sub-group of processed foods that include yogurt and dairy-based desserts actually improved the risk of colorectal cancer in women.
“One of the things that we know from yogurt, in particular, is that it’s fermented, which can benefit the gut microbiome,” explains Feller. The gut’s overall health can impact many functions (like immune health and hormone function), but Feller notes that feeding your gut microbiome these favorable bacteria from yogurt can specifically improve inflammation, which is linked to colorectal health. Additionally, many dairy products include nutrients like calcium, vitamin D, potassium, and protein that may not be present in other processed foods.
A second study and analysis published in The British Medical Journal assessed the diets of more than 22,000 people in the Molise region of Italy and their mortality risk after 14 years of follow-up. Researchers analyzed two food classification systems—the Food Standards Agency Nutrient Profiling System (FSAm-NPS index) used for color-coding nutritional scores on labels and the NOVA scale, an evaluation of the degree of food processing.
The study found that those who ate nutrient-poor foods and ultra-processed foods had a higher risk of developing chronic disease or premature death, especially from cardiovascular disease. Researchers estimated those with the least healthy diet based on the FSAm-NPS index had a 19% higher risk of death from any cause and a 32% risk of death from cardiovascular disease compared to those with the healthiest diet. Additionally, those with the least-healthy diet based on the NOVA scale had a 19% and 27% higher risk for all-cause and cardiovascular mortality respectively.
While researchers considered the diet scores, nutrition patterns, sex assigned at birth, and race of participants, they didn’t consider social determinants of health—a deterrent of this study, per Feller. Socioeconomic background and education can play a major part in a person’s overall health and access, she says.
The bottom line
Feller explains that the key takeaway from the research is that scientists were really looking at Western patterns of eating a highly processed-food diet including things with additives, higher amounts of sugar, salt, and saturated and synthetic fats instead of foods with nutrients.
We’ve long known ultra-processed foods should be consumed sparingly in the diet. Previous research from earlier this year found that ultra-processed foods can negatively impact cognitive function, and a recent study linked charcuterie with an increased risk for colon cancer. Other research found eating a little over five ounces of processed meat per week may put you at greater risk for heart disease and early death, and additional research found sugary drinks can spike the risk of colorectal cancer in young people.
And the American Heart Association (AHA) is paying attention, adjusting its guidance to reflect findings. The AHA suggests choosing minimally-processed foods and minimizing beverages with added sugars and instead opting for fresh fruits and vegetables when the opportunity presents itself.
Arielle Weg is the associate editor at Prevention and loves to share her favorite wellness and nutrition obsessions. She previously managed content at The Vitamin Shoppe, and her work has also appeared in Women’s Health, Men’s Health, Cooking Light, MyRecipes, and more. You can usually find her taking an online workout class or making a mess in the kitchen, creating something delicious she found in her cookbook collection or saved on Instagram.