Additives in Ultra-Processed Foods Tied to Higher All-Cause Mortality, Large UK Study Finds

A large UK cohort study published in eClinicalMedicine found that higher intake of ultra-processed foods and certain additives commonly present in those products was associated with an increased risk of death from any cause over roughly 11 years of follow-up.

Researchers analyzed dietary and health data from nearly 187,000 adults aged 40 to 75 drawn from the U.K. Biobank. Participants completed multiple online 24-hour food diaries, and investigators matched reported foods to supermarket product ingredient lists to identify 57 potential markers of processed-food additives. Each food item was scored for its likelihood of containing a given additive, and investigators calculated what percentage of a participant’s total daily intake, by weight, consisted of ultra-processed foods and particular additive categories.

The analysis identified five additive categories that showed significant associations with higher all-cause mortality when compared with the study’s lowest-risk intake levels: flavorings, flavor enhancers, coloring agents, non-nutritive sweeteners (such as acesulfame, saccharin and sucralose), and certain forms of sugar including fructose, inverted sugar, lactose and maltodextrin. Gelling agents were the only additive group associated with a lower risk in the study.

Investigators reported that mortality risk began to rise once ultra-processed foods made up more than 18% of total intake by weight. Modeled estimates in adjusted analyses showed a 6% higher risk at 30% of the diet, 14% at 40% and 19% at 50%. For specific additive categories, the study estimated about a 20% higher risk when flavored foods constituted 40% of intake versus 10%, roughly a 24% higher risk for coloring agents at 20% versus 3%, and about a 14% higher risk for non-nutritive sweeteners at 20% of intake compared with none.

Models were adjusted for a range of potential confounders, including age, sex, smoking status, body mass index, blood pressure, alcohol use, physical activity and household income. The authors emphasized that the findings concern associations with all-cause mortality rather than particular diseases.

The study’s methodology—linking self-reported 24-hour recalls to product ingredient lists—allowed a more granular look at likely additive exposure than many prior analyses, but the authors and external experts noted limitations. As observational research, the study cannot establish causation, and residual confounding is possible because people who consume more ultra-processed foods may differ in other health behaviors or environmental exposures that affect outcomes. Self-reported dietary recalls and product matching may introduce measurement error, and the additive scores represented probabilities rather than direct measurements of individual exposure.

Public-health organizations and clinicians have increasingly focused on ultra-processed foods. The U.S. Centers for Disease Control and Prevention has reported that a majority of Americans obtain more than half of their calories from ultra-processed foods. Professional groups such as the American Heart Association recommend limiting ultra-processed food intake and emphasize diets rich in vegetables, fruits, whole grains, beans, nuts, seeds, healthy non-tropical oils and lean proteins.

Tara Schmidt, lead dietitian for the Mayo Clinic Diet, said on the clinic’s website that overconsumption of ultra-processed foods has been linked to adverse health outcomes but that not all processed foods are inherently harmful for every person in every situation. She advised that reducing large, frequent portions of ultra-processed products will likely have a greater health impact than eliminating items eaten rarely.

The authors of the eClinicalMedicine study called for further research to replicate their findings in other populations and to explore biological mechanisms that might link particular additives to health outcomes. They also noted the need for studies that directly measure additive exposure and account for product reformulations over time.

Until more definitive evidence is available, clinicians and public health agencies continue to recommend whole-food–based dietary patterns and reducing reliance on ultra-processed products as a prudent approach for population-level health promotion.