A new study has raised fresh concerns about the long-term impact of ultra-processed foods on brain health, linking high consumption to a substantially increased risk of dementia.
Researchers from the Harvard T.H. Chan School of Public Health, in findings published in the American Journal of Public Health, reported that adults who regularly consume large amounts of ultra-processed foods may face up to a 58% higher risk of developing dementia compared to those with the lowest intake.
Large-scale analysis of dietary patterns
The study analysed data from more than 5,300 adults aged 50 and above, drawing on information from the University of Michigan’s long-running Health and Retirement Study. Participants were followed for an average of five years, during which researchers assessed dietary habits and cognitive health outcomes.
Ultra-processed foods, according to the Nova classification system used in the study, include industrially manufactured products that contain little to no whole foods. These typically consist of packaged snacks, soft drinks, processed meats, and other convenience products with multiple artificial additives.
Key findings on cognitive decline
Researchers found that individuals in the highest consumption group of ultra-processed foods had a 58% higher risk of dementia and a 46% increased risk of cognitive impairment compared with those who consumed the least.
Processed meats such as bacon, hot dogs, and deli slices showed the strongest association with increased risk, standing out even among other ultra-processed categories linked to poorer cognitive outcomes.
Notably, the study also suggested that moderate consumption was not risk-free. Participants with mid-level intake of ultra-processed foods still showed elevated risks compared to those with minimal consumption, challenging the assumption that occasional intake is harmless.
Conversely, diets rich in minimally processed foods such as fruits, vegetables, and whole grains were associated with lower risks of both dementia and cognitive decline.
Adds to growing body of evidence
Although the study was observational and cannot establish direct causation, it aligns with a growing body of research pointing to potential neurological risks associated with ultra-processed diets.
Previous studies published in journals including Alzheimer’s & Dementia and The Journal of Prevention of Alzheimer’s Disease have similarly linked high intake of ultra-processed foods to reduced attention, memory impairment, and increased Alzheimer’s disease risk. Other research has also suggested possible effects beginning early in life, including associations between childhood ultra-processed food consumption and lower cognitive performance.
Public health implications
The researchers noted that improving access to healthier food options and promoting dietary education could help reduce long-term cognitive health risks at the population level.
For individuals, experts continue to recommend reducing reliance on heavily processed foods and increasing consumption of whole, minimally processed ingredients as part of a brain-healthy diet.
While further research is needed to establish causation, the findings add to growing evidence that long-term dietary choices may play a significant role in cognitive health and dementia risk.
