New study identifies association between ultra-processed foods and shorter life
Consumption of “ultra-processed” foods could lead to a higher risk of death, according to a new major French study published Monday in JAMA Internal Medicine.
The study monitored diet and health between 2009 and 2017 in about 45,000 French men and women who were 45 years or older and participating in the ongoing cohort from the French NutriNet-Santé Study. Every six months, selected participants were asked to fill out three online surveys, randomly assigned over two weeks, documenting everything they ate or drank over a 24-hour period. Increased consumption of ultra-processed was modestly linked to heightened mortality risk during that period.
Researchers defined ultra-processed foods as “ready-to-eat or -heat formulations made mostly from ingredients usually combined with additives.” About 29 percent of participants calorie intake was ultra-processed, examples of which include packaged snacks and baked goods, chicken or fish nuggets, reconstituted meat products, and instant noodles and soup.
Over the course of the study, there were over 600 deaths, mostly from cancer and cardiovascular disease. After adjusting for several health, socioeconomic, and behavioral considerations, researchers found a 10 percent increase in the proportion of ultra-processed foods in the diet corresponded to a 15 percent increase in mortality.
The study authors suggest high-temperature processing may form contaminants and that packaging prepared foods may lead to contamination. They also elude that additives may be carcinogenic.
Ultra-processed foods were defined under the from the NOVA food classification system, recognized by health agencies including the Food and Agriculture Organization of the United Nations. Last year, researchers published data from the French NutriNet-Santé Study, noting more cancer diagnoses among heavy consumers of these foods.
Since it is ethically impossible to conduct a controlled experiment in which one group eats ultra-processed foods and the other does not, researchers are limited to observational studies. These studies, though they are typically adjusted to compensate for sociodemographic and other criteria, rely on accurate self-reporting and cannot reasonably account for every possible factor at play.
Experts stress the relationship between diet and disease is complex, and the results of studies are often misinterpreted. In this study, authors say there is association, but they cannot prove it is causal, meaning people who consume ultra-processed foods are not guaranteed to develop a chronic disease.
Additional research is needed, as well as advocacy to make ultra-processed foods less accessible, and make healthier options more affordable for all.