A new study has found that people who eat more ultra-processed foods—such as soft drinks, chips, cookies, and packaged breads—may face a greater risk of stroke and problems with memory and thinking.
The research, published in the journal Neurology, shows an association but does not prove that processed foods directly cause these health issues.
Ultra-processed foods are usually high in added sugars, unhealthy fats, and salt, while being low in protein and fiber.
Examples include sodas, ice cream, hamburgers, flavored cereals, canned baked beans, ketchup, mayonnaise, and packaged snacks. In contrast, unprocessed or minimally processed foods include fresh vegetables, fruits, and simple cuts of meat such as chicken, beef, or pork.
Dr. W. Taylor Kimberly of Massachusetts General Hospital, who led the study, explained that while healthy eating is known to support brain health, the most important food choices are still being identified.
This research adds to growing evidence that eating large amounts of ultra-processed foods may speed up cognitive decline and increase stroke risk. The effect was found to be even stronger among Black participants.
The study followed more than 30,000 adults over age 45, who identified as either Black or white, for an average of eleven years. None of them had stroke or cognitive problems at the start. Participants filled out detailed food questionnaires, and researchers calculated how much of their daily diets came from processed versus unprocessed foods.
The results were concerning. Among the group studied for memory and thinking, 768 people developed cognitive impairment during the study. These people got about 25.8% of their daily calories from ultra-processed foods, compared to 24.6% for those who stayed healthy.
After adjusting for factors like age, sex, and high blood pressure, the researchers found that every 10% increase in processed food consumption was linked to a 16% higher risk of developing memory and thinking problems. On the other hand, eating more fresh or minimally processed foods reduced the risk by about 12%.
Among the stroke group, 1,108 people had a stroke during the study. They ate about 25.4% of their diets from processed foods, compared to 25.1% for those who did not. Even small differences in diet mattered.
Greater intake of ultra-processed foods was tied to an 8% higher risk of stroke, while greater intake of unprocessed foods lowered risk by 9%. The link was strongest among Black participants, where eating more processed foods was associated with a 15% higher risk of stroke.
Dr. Kimberly emphasized that the degree of processing itself appears to matter for brain health. The study suggests that limiting packaged and highly processed items and eating more whole, natural foods could help protect memory and reduce stroke risk.
However, the researchers noted that more work is needed to confirm these results and identify which ingredients or processing methods are most harmful.
A limitation of the study is that it only included participants who identified as Black or white, so the findings may not apply to all populations. Still, with more than 30,000 participants followed for over a decade, the evidence is strong and raises important questions for public health.
This research highlights how everyday food choices can have long-term effects on brain and heart health. Choosing more fresh foods and fewer packaged items may be a simple but powerful step in protecting the body and mind as we age.
If you care about dementia, please read studies about Dizziness upon standing may be linked to dementia risk and findings of Scientists find the ties between high blood pressure and dementia.
For more about dementia, please read studies about Early heart rhythm problem linked to higher dementia risk and findings of Green leafy vegetables may help reduce Alzheimer’s risk.
The study is published in Neurology.
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