Older persons who reported consuming more ultra-processed foods were nearly 10 per cent more likely to die after a median follow-up of 23 years than older adults who reported consuming less processed food, according to a recent study.

The study observed that highly processed meat and soft drinks were a couple of the subgroups of ultra-processed food most strongly associated with mortality risk. (Shutterstock)

The results are drawn from a sizable study that followed more than 500,000 persons in the United States for about thirty years. The findings showed that consuming more ultra-processed foods was linked to slight increases in deaths from heart disease and diabetes, as well as deaths from all causes. However, there was no correlation observed in deaths from cancer.

“Our study results support a larger body of literature, including both observational and experimental studies, which indicate that ultra-processed food intake adversely impacts health and longevity,” said Erikka Loftfield, PhD, Stadtman Investigator at the National Cancer Institute. “However, there is still a lot that we don’t know, including what aspects of ultra-processed foods pose potential health risks.”

Loftfield will present the findings at NUTRITION 2024, the flagship annual meeting of the American Society for Nutrition held June 29 to July 2 in Chicago. (Also Read | How often should you really weigh yourself?)

The research drew data from more than 540,000 people who provided information about their eating habits and health in the mid-1990s, when they were between 50 and 71 years of age. Over half of the participants have since died. The researchers analysed overall rates of death among those who were in the 90th percentile for consumption of ultra-processed foods at baseline versus those in the 10th percentile, and also looked at associations with specific foods and specific diseases.

“We observed that highly processed meat and soft drinks were a couple of the subgroups of ultra-processed food most strongly associated with mortality risk and eating a diet low in these foods is already recommended for disease prevention and health promotion,” said Loftfield. The Dietary Guidelines for Americans recommend limiting sugar-sweetened beverages and processed meats such as hot dogs, sausages and deli meat.

For this study, researchers used multiple strategies to classify the level of processing for various food items. This included breaking down food frequency questionnaire data into particular food and ingredient types in addition to incorporating expert consensus to categorize dietary components according to a rubric known as the NOVA classification system.

The researchers also accounted for other factors that can increase a person’s risk of death, such as smoking and obesity. They found that people who consumed more ultra-processed foods also tended to have higher body mass index and a lower Healthy Eating Index score (a measure of diet quality based on how closely a person’s diet aligns with the Dietary Guidelines for Americans). 

However, the analysis showed that the associations between ultra-processed food consumption and increased mortality were not explained by these variables, as the associations between higher ultra-processed food intake and mortality risk persisted among people categorized as having better or worse diet quality as well as among those classified as normal weight or obese.