Here are the Ultraprocessed foods you most need to avoid, according to a 30-year study.

A 30-year study has linked the consumption of ultraprocessed foods to an increased risk of early death, with varying impacts depending on the type of food.

Ultraprocessed foods, as defined by the Food and Agriculture Organization of the United Nations, are those containing ingredients “never or rarely used in kitchens” or additives that enhance flavor and appeal. These ingredients are commonly found in products like sodas, chips, packaged soups, nuggets, and ice cream, and may include preservatives, artificial coloring, emulsifiers, and added or altered sugars, salts, and fats.

Dr. Mingyang Song, associate professor of clinical epidemiology and nutrition at Harvard’s TH Chan School of Public Health, noted that processed meats and sugary foods and drinks pose different risks compared to ultraprocessed whole grains. The study, which analyzed data from over 100,000 U.S. health professionals with no prior history of cancer, cardiovascular disease, or diabetes, collected health and lifestyle information biennially from 1986 to 2018. Participants also completed detailed food questionnaires every four years.

According to the study published in The BMJ journal, those who consumed the most ultraprocessed food—averaging seven servings per day—had a 4% higher risk of death from any cause and a 9% increased risk of neurodegenerative death compared to those who ate the least (about three servings per day). Dr. Song described the correlation as “moderate,” emphasizing that not all ultraprocessed foods are equally harmful. The greatest risks were associated with processed meats and sugar-sweetened or artificially sweetened beverages.

Dr. Marion Nestle, professor emerita of nutrition, food studies, and public health at New York University, highlighted the uniqueness of this study in its detailed examination of subgroups within the ultraprocessed food category. While some ultraprocessed foods like cereals and whole grain breads contain beneficial nutrients such as fiber, vitamins, and minerals, others like processed meats and sugary beverages should be limited.

Dr. Peter Wilde, emeritus fellow at Quadram Institute Bioscience, pointed out that the study’s observational nature means it can identify correlations but not causation. He emphasized the need for further research on the components of ultraprocessed foods that might impact health, such as food additives and emulsifiers.

Overall, the quality of a person’s diet remains the most crucial factor in reducing the risk of death, Dr. Song said. A healthy diet includes a variety of colorful fruits, vegetables, and whole grains. Dr. Wilde advised choosing foods with low levels of additives and being mindful of the nutritional content of ultraprocessed foods consumed. Balance is key, as even beneficial foods like fruit juice can have adverse effects if consumed in excess due to high sugar levels.

“This is not black and white,” Wilde concluded. “A particular food is not either good or bad; it will contain elements of both, and the balance between the two may depend on how much you eat.”