Massive New Study Presents Strongest Evidence Yet Linking Processed Foods to Range of Health Problems

Most of us know that potato chips, store-bought pastries, and sodas aren't the foundation of a healthy diet. But how bad for us are these foods, really? A new review of research involving nearly 10 million participants offers some of the most compelling evidence yet that highly processed foods undermine our mental and physical health.

For the comprehensive review, published in the British medical journal BMJ, researchers pooled data from 14 studies, which encompassed 9,888,373 participants in all, to look at connections between ultra-processed foods (UPFs) and different health outcomes, including Type 2 diabetes, anxiety, cancer, and early death. For their definition of ultra-processed foods, the researchers referred to the NOVA system, which classifies foods according to their level of processing. They included only studies published within the last three years, and excluded any studies that received funding from manufacturers of UPFs.

Upon completing their analyses, they found that consumption of highly processed foods was linked to a higher risk of 32 of the 45 adverse health outcomes under investigation. The researchers noted that the most convincing evidence involved mental health and cardiometabolic health: Participants who ate more highly processed foods were 53% more likely to suffer from anxiety and/or depression and 50% more likely to die of cardiovascular disease. They were also 12% more likely to have Type 2 diabetes.

In an editorial appearing in the same issue of BMJ, Carlos A. Monteiro, who developed the NOVA food classification system used in this and numerous other nutrition studies, commented on the findings: “Overall, the authors found that diets high in ultra-processed food may be harmful to most—perhaps all—body systems.”

Also known as highly processed foods, UPFs make up more than 50% of daily calories consumed in the U.S. Common examples include sweetened breakfast cereals, salty snack foods, soda, and store-bought pastries. UPFs have come under increased scrutiny in recent years, with other studies linking diets high in these foods to dementia and inflammatory bowel disease, among other issues. Made primarily with synthesized and extracted ingredients, UPFs tend to be high in calories, sugar, salt, and fat and low in fiber and other nutrients.

To learn more about a whole-food, plant-based diet, visit our Plant-Based Primer. For meal-planning support, check out Forks Meal Planner, FOK’s easy weekly meal-planning tool to keep you on a healthy plant-based path.