A new study reveals that older adults consuming higher amounts of ultra-processed foods, as classified by the NOVA system, face a roughly 10% increased risk of death over a median follow-up period of 23 years compared to those who consume less processed food.
This extensive research has tracked over half a million U.S. adults for nearly three decades. The findings show a modest increase in death from any cause, particularly from heart disease or diabetes, linked to higher intake of ultra-processed foods. However, no significant association was found for cancer-related deaths.
These findings will be presented by Loftfield at NUTRITION 2024, the flagship annual meeting of the American Society for Nutrition, held from June 29 to July 2 in Chicago.
The study analyzed data from more than 540,000 individuals who detailed their eating habits and health status in the mid-1990s, when they were between 50 and 71 years old. Over half of the participants have since died. Researchers compared overall death rates between those in the highest (90th percentile) and lowest (10th percentile) consumption brackets for ultra-processed foods and examined associations with specific foods and diseases.
“We observed that highly processed meat and soft drinks were among the subgroups of ultra-processed foods most strongly associated with mortality risk,” said Loftfield. “Eating a diet low in these foods is already recommended for disease prevention and health promotion.” The Dietary Guidelines for Americans advise limiting sugar-sweetened beverages and processed meats like hot dogs, sausages, and deli meat.
To classify the level of food processing, researchers employed various strategies, including detailed food frequency questionnaires and expert consensus, categorizing dietary components according to the NOVA classification system.
The study also accounted for other mortality risk factors such as smoking and obesity. It found that individuals who consumed more ultra-processed foods tended to have a higher body mass index and a lower Healthy Eating Index score—a measure of diet quality based on alignment with the Dietary Guidelines for Americans. Nevertheless, the increased mortality risk associated with ultra-processed food consumption persisted across different levels of diet quality and among those of normal weight and those classified as obese.
One limitation of the study is its design, which does not establish causality. Additionally, Loftfield noted that the U.S. food supply and dietary preferences have evolved significantly since the baseline data were collected in the mid-1990s. This underscores the need for ongoing research to further understand the relationship between food processing and human health.