Healthful diet linked to reduced risk of cognitive decline

The MIND diet, which merges key features of the Mediterranean and the DASH diets, may help slow cognitive decline. Serjio / Adobe Stock

Dementia—a loss of thinking, remembering, and reasoning skills that affects everyday life—is a growing concern. It’s often preceded years in advance by memory and thinking problems, including cognitive decline and mild cognitive impairment. Interventions that prevent or delay these problems might help to reduce the risk of dementia.

Some studies have linked healthy eating patterns to improved cognitive function. Examples include the Mediterranean diet, which emphasizes fruits, vegetables, and lean proteins, and the DASH eating plan, designed to treat or prevent hypertension.

The MIND diet merges key features of the Mediterranean and the DASH diets. MIND stands for Mediterranean-DASH Intervention for Neurodegenerative Delay. It aims to protect brain health. The diet features green leafy vegetables and other vegetables, prefers berries over other fruit, and endorses whole grains, beans, nuts, and at least one weekly serving of fish. It limits red meat, sweets, cheese, fast food, and fried foods.

A research team led by Dr. Russell P. Sawyer of the University of Cincinnati studied whether the MIND diet is linked to cognitive health. They also looked for potential differences between Black and White Americans and between genders. Many earlier studies of diet and cognitive health have underrepresented Black participants.

The researchers drew on data from a large ongoing NIH-supported study called REGARDS (REasons for Geographic and Racial Differences in Stroke). REGARDS is designed to assess why Black Americans and others have increased rates of stroke and related conditions that affect brain health. Of the 30,000 REGARDS participants, about 14,000 had sufficient data on their cognitive status and eating patterns to be included in the new analysis. Their average age was about 64 at the start of the study. About 57% were female, 70% were White, and 30% were Black. They were followed for about 10 years.

The research team created a score for each participant based on how closely their self-reported eating patterns adhered to MIND diet recommendations. Cognitive health was measured at the beginning and end of the study. Results were reported in Neurology on September 18, 2024.

Overall, the researchers found that, after adjusting for demographic and other factors, closer adherence to the MIND diet was linked to lower cognitive impairment and slower rates of cognitive decline. Participants with greatest adherence to the MIND diet had a 4% reduced risk of cognitive impairment compared to those with lowest adherence.

The team also found that closer following of the MIND diet was associated with an 8% lower risk of cognitive decline in female participants but no difference in males. And greater adherence to the diet was a better predictor of cognitive decline in Black than in White participants.

The researchers note that their findings generally align with earlier studies that examined associations between cognitive health and MIND and similar diets. But additional studies are needed to better understand the role that healthy eating may play in cognitive health.

“With the number of people with dementia increasing with the aging population, it’s critical to find changes that we can make to delay or slow down the development of cognitive problems,” Sawyer says. “These findings warrant further study, especially to examine these varying impacts among men and women and Black and White people.”

—by Vicki Contie