A recent study indicates that a high consumption of ultra-processed foods is associated with an increased risk of cognitive impairment and stroke, particularly among older adults and more significantly among black participants. This correlation prompts further investigation into how food processing impacts brain health.
Eating more ultra-processed foods may elevate the risk of cognitive issues and stroke, with the impact being particularly significant among black individuals.
People who eat more ultra-processed such as soft drinks, chips, and cookies may have a higher risk of having memory and thinking problems and having a stroke than those who eat fewer processed foods. This is according to a new study published today in the May 22, 2024, online issue of Neurology, the medical journal of the American Academy of Neurology. Note that the study only shows an association. It does not prove that eating ultra-processed foods causes memory and thinking problems and stroke.
Ultra-processed foods typically contain high levels of added sugars, fats, and salt while being low in protein and fiber. Examples of these foods include soft drinks, sugary and salty snacks, ice cream, hamburgers, canned baked beans, ketchup, mayonnaise, packaged bread, and flavored cereals. In contrast, unprocessed or minimally processed foods mainly consist of simple cuts of meats like beef, pork, and chicken, as well as fruits and vegetables.
Study Details and Findings on Diet Impact
“While a healthy diet is important in maintaining brain health among older adults, the most important dietary choices for your brain remain unclear,” said study author W. Taylor Kimberly, MD, PhD, of Massachusetts General Hospital in Boston. “We found that increased consumption of ultra-processed foods was associated with a higher risk of both stroke and cognitive impairment, and the association between ultra-processed foods and stroke was greater among black participants.”
For the study, researchers looked at 30,239 people aged 45 or older who self-identified as black or white. They were followed for an average of eleven years.
Participants filled out questionnaires about what they ate and drank. Researchers determined how much ultra-processed food people ate by calculating the grams per day and comparing it to the grams per day of other foods to create a percentage of their daily diet. That percentage was calculated into four groups, ranging from the least processed foods to the most processed foods.
Of the total participants, researchers looked at 14,175 participants for cognitive decline and 20,243 participants for stroke. Both groups had no history of cognitive impairment or stroke.
By the end of the study, 768 people were diagnosed with cognitive impairment and 1,108 people had a stroke.
Cognitive Decline
For those in the cognitive group, people who developed memory and thinking problems consumed 25.8% of their diet in ultra-processed foods, compared to 24.6% for those who did not develop cognitive problems.
After adjusting for age, sex, high blood pressure, and other factors that could affect the risk of dementia, researchers found that a 10% increase in the amount of ultra-processed foods eaten was associated with a 16% higher risk of cognitive impairment.
They also found that eating more unprocessed or minimally processed foods was linked with a 12% lower risk of cognitive impairment.
Stroke Risk Among Different Demographics
For those in the stroke group, people who had a stroke during the study consumed 25.4% of their diet in ultra-processed foods, compared to 25.1% for those who did not have a stroke.
After adjustments, researchers found greater intake of ultra-processed foods was linked to an 8% increase in risk of stroke, while a greater intake of unprocessed or minimally processed foods was linked to a 9% decreased risk of stroke.
The effect of ultra-processed food consumption on stroke risk was greater among black participants, with a 15% relative increase in risk of stroke.
Conclusion and Limitations of the Study
“Our findings show that the degree of food processing plays an important role in overall brain health,” Kimberly said. “More research is needed to confirm these results and to better understand which food or processing components contribute most to these effects.”
A limitation of the study was that only participants who self-identified as black or white were included in the study, so results may not be generalizable to people from other populations.
Reference: 22 May 2024, Neurology.
The study was funded by the National Institute of Neurological Disorders and Stroke, the National Institute on Aging, National Institutes of Health and Department of Health and Human Services.
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