Beyond ingredients: How ultra-processed foods are making you sick

Ultra-processed foods (UPFs) have long been linked to chronic diseases, including heart disease, diabetes and premature death. A groundbreaking new study by researchers at Tufts University has now found that the real problem is not just the ingredients in these foods, but how they are made.In findings published in the American Journal of Public Health, researchers suggested that processing itself may play an independent role. They also found that people who consumed more UPFs had worse health outcomes, even after accounting for the overall nutritional quality of the foods.UPFs are often high in saturated fat, sodium and added sugars, which are linked to numerous diseases, including heart disease. The new study by researchers at the Food is Medicine Institute at the Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University looks at the concerning industrial processing and additives that make these foods even worse.“The findings suggest ultra-processed food factors beyond nutrients—such as changes to foods’ cellular structure, loss of beneficial chemical compounds, additives, and chemicals from packaging—may create health risks not addressed by traditional nutrition metrics or policies,” said the study’s senior author, Dariush Mozaffarian, cardiologist and director of the Food is Medicine Institute.The research team analysed data spanning nearly two decades, using information from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018, linked with mortality data through 2018. The study participants had completed one or two 24-hour dietary recalls. Researchers grouped foods based on how they were made, ranging from minimally processed food-based ingredients such as fruits and vegetables to ultra-processed products made with industrial ingredients and additives not typically used in cooking. The nutritional quality of foods was also rated, and participants’ diet-quality scores were assessed. The researchers examined how ultra-processed food consumption was linked to current health measures, such as weight, blood sugar and cholesterol, as well as long-term risk of death.The researchers found that for every 10% increase in calories from ultra-processed foods, health markers worsened. People who consumed more UPFs had higher body weight, poorer blood sugar control, higher blood pressure and less favourable cholesterol levels. They were also more likely to have conditions such as diabetes, metabolic syndrome and cancer, and had a slightly higher risk of dying during the study period. These links remained even after the researchers accounted for the ingredients and nutritional quality.“Ultra-processed foods make up a substantial portion of the American diet, accounting for more than 50% of adults’ and about 60% of children’s caloric intake. Understanding how these foods affect health is a critical public health priority, given the large proportion of the population affected,” said Juna Hatta-Langedyk, first author and an undergraduate biology student at Tufts.“Addressing structural and policy-related barriers to accessing fresh and minimally processed foods remains critical for promoting dietary changes that improve health and lifespan for all Americans. Our findings can help inform many current policy efforts, such as a national definition of ultra-processed foods and multiple states’ efforts to propose and pass laws addressing ultra-processed foods, including warning labels, bans on certain additives and limits in school meals,” Mozaffarian added.