Eating Ultra-Processed Foods Could Be As Harmful as Smoking

People who eat large amounts of ultra-processed foods show significantly higher inflammation levels tied to heart disease and cancer.

Scientists say the growing dependence on these foods may rival tobacco in long-term health impact.

Ultra-Processed Foods Dominate Modern Diets

Ultra-processed foods (UPFs) are highly manufactured products such as soda, packaged snacks, and processed meats. They are filled with additives and lack essential nutrients. In the United States, hundreds of ingredients that the human body was never exposed to before are now common in these foods, which make up nearly 60% of the typical adult diet and close to 70% of what children eat.

These products are designed to last longer, taste appealing, and encourage overeating while providing little nutritional value. In fact, UPFs supply about 60% of the calories consumed each day in the U.S. A growing body of research links heavy consumption of these foods to increased risks of obesity, cancer, heart and metabolic diseases, mental health disorders, and even early death.

Inflammation: The Dangerous Link Revealed

A new study from Florida Atlantic University’s Charles E. Schmidt College of Medicine has uncovered a clear connection between UPF intake and inflammation in the body. The researchers found that people who eat the most UPFs have much higher levels of high-sensitivity C-reactive protein (hs-CRP), a reliable indicator of inflammation and a strong predictor of cardiovascular disease.

Previously, there was little nationally representative data in the U.S. exploring how UPF consumption relates to hs-CRP levels.

According to findings published in The American Journal of Medicine, participants got a median of 35% of their daily calories from UPFs. Consumption ranged from 0% to 19% in the lowest group to 60% to 79% in the highest. After adjusting for age, gender, smoking, physical activity, and other health factors, those in the highest UPF group (60% to 79% of daily calories) were 11% more likely to have elevated hs-CRP levels than those in the lowest group. Even moderate consumers (40% to 59%) showed a 14% higher likelihood, while the group consuming 20% to 39% had a smaller, statistically insignificant 7% increase.

Who Faces the Greatest Risk?

The likelihood was especially high in certain groups. Adults aged 50 to 59 had a 26% higher risk of elevated inflammatory markers compared to those aged 18 to 29. Obesity contributed to an 80% higher risk compared to people with a healthy weight. Current smokers also had a higher risk (17%) than people who never smoked. Interestingly, individuals who reported no physical activity did not have a statistically significant increase in risk compared to those who met activity guidelines.

“These findings, based on a large and nationally representative sample of U.S. adults, clearly show that people who consume the highest amounts of ultra-processed foods have significantly higher levels of high-sensitivity C-reactive protein, a key marker of inflammation,” said Allison H. Ferris, M.D., FACP, senior author, professor and chair of the FAU Department of Medicine. “These results carry important implications not only for clinical practice and public health strategies but also for future research aimed at understanding and reducing the health risks associated with ultra-processed food consumption.”

Researchers analyzed data from 9,254 U.S. adults in the National Health and Nutrition Examination Survey, including diet, hs-CRP and other health factors. UPF intake was measured as a percentage of total calories and grouped into four levels. They used statistical methods, including logistic regression, to examine the link between UPF consumption and inflammation.

Expert Insights on Inflammation Markers

“C-reactive protein is produced by the liver, and the hs-CRP protein test is a simple, affordable and highly sensitive measure of inflammation as well as a reliable predictor of future cardiovascular disease,” said Charles H. Hennekens, M.D., FACPM, FACC, co-author, the First Sir Richard Doll Professor of Medicine and Preventive Medicine, and senior academic advisor, Schmidt College of Medicine. “We believe that health care professionals may wish to consider actively engaging with their patients about the risks of UPFs and benefits of increasing whole food consumption.”

The authors also highlight a significant rise in colorectal cancer rates in the U.S., particularly among younger adults. They suggest that increased consumption of UPFs may be a contributing factor, along with its potential role in several other gastrointestinal diseases.

Lessons From Tobacco History

Drawing a parallel to the history of tobacco, the authors note that it took decades for mounting evidence and the efforts of progressive health officials to lead to policies discouraging cigarette use. They believe a similar trajectory is likely for UPFs, with growing awareness eventually driving meaningful public health action.

“The multinational companies that produce ultra-processed foods are very influential, much like tobacco companies were in the past, so policy changes to promote whole foods and reduce UPF consumption may take time,” said Hennekens. “However, government efforts to reduce harmful additives, improve food labeling, and promote healthier options in programs and schools are important steps in the right direction. At the same time, health care providers should be aware of the challenges many people face in accessing affordable, healthier choices, which calls for a broader and coordinated public health response.”

Reference: “Ultra-processed foods and increased high sensitivity C-reactive protein” by Kevin Sajan, Nishi Anthireddy, Alexandra Matarazzo, Caio Furtado, Charles H. Hennekens and Allison Ferris, 3 September 2025, The American Journal of Medicine.
DOI: 10.1016/j.amjmed.2025.08.016

Study co-authors are Kevin Sajan, a medical student at Geisinger Commonwealth School of Medicine; Nishi Anthireddy, a medical student at FAU; Alexandra Matarazzo, a medical student at FAU; and Caio Furtado, M.D., a resident physician in FAU’s internal medicine residency program.

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