Cognitive Decline Linked to Ultra-Processed Foods

A recent study that was published in the online edition of Neurology, the medical journal of the American Academy of Neurology, on May 22, 2024, suggests that people who consume more ultra-processed foods, such as cookies, chips, and soft drinks, may be at an increased risk of stroke, memory loss, and cognitive decline. The study does not establish a link between eating foods with high processing levels and memory loss or stroke. It merely displays a correlation.

Ultra-processed foods are poor in fiber and protein and heavy in added sugar, fat, and salt. These include flavored cereals, packaged breads, soft beverages, ice cream, hamburgers, canned baked beans, ketchup, and mayonnaise. Foods that are unprocessed or just slightly processed include fruits, vegetables, and meats such as lean cuts of beef, hog, and chicken.

While a healthy diet is important in maintaining brain health among older adults, the most important dietary choices for your brain remain unclear. 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.” – W. Taylor Kimberly, MD, PhD, study author of Massachusetts General Hospital in Boston

Researchers examined 30,239 Black and White individuals who self-identified as being 45 years of age or older for the study. They were observed for eleven years on average.

Questionnaires regarding their diet and hydration were completed by the participants. By measuring the grams per day and comparing it to the grams per day of other foods to produce a percentage of the daily diet, researchers were able to calculate how much ultra-processed food people ate. From the least processed foods to the most processed foods, that proportion was divided into four groups.

Researchers examined 20,243 patients for stroke and 14,175 participants for cognitive decline out of the total number of subjects. Neither group had ever experienced a stroke or cognitive impairment.

After the research, 1,108 persons had suffered a stroke and 768 people had been diagnosed with cognitive impairment.

Those in the cognitive group that experienced memory and cognitive difficulties ingested ultra-processed foods for 25.8% of their diet, while those who did not experience cognitive problems only consumed 24.6%.

Researchers discovered that a 16% increased risk of cognitive impairment was linked to a 10% increase in the amount of ultra-processed foods consumed, even after controlling for age, sex, high blood pressure, and other variables that may influence dementia risk.

Additionally, they discovered a 12% decreased risk of cognitive impairment was associated with eating a diet higher in raw or little processed foods.

Individuals in the stroke group consumed ultra-processed foods for 25.4% of their diet during the trial, while those without a stroke consumed 25.1%.

There was a 15% relative increase in the risk of stroke among Black participants who consumed more ultra-processed foods.

“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.”

The fact that the study only included participants who self-identified as Black or White presented a constraint, as results might not apply to individuals from other populations.

The Department of Health and Human Services, the National Institutes of Health, the National Institute on Aging, and the National Institute of Neurological Disorders and Stroke provided funding for the study.

For more information: Associations Between Ultra-processed Food Consumption and Adverse Brain Health Outcomes, Neurology, https://doi.org/10.1212/WNL.0000000000209432