This diet may slow cognitive decline after stroke

After showing that the "MIND" diet can reduce the risk of developing Alzheimer's, researchers are now tackling stroke.

The MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diet was developed by Martha Clare Morris , a professor of epidemiology and director of the Section of Nutrition and Nutritional Epidemiology at Rush University Medical Center in Chicago, IL.

It uses elements of both the DASH (Dietary Approaches to Stop Hypertension) and the Mediterranean diets.

Aimed at promoting brain health, the MIND diet focuses heavily on consumption of vegetables, nuts, beans, fish, poultry, whole grains, olive oil, and a moderate consumption of wine. Foods to be avoided include red meats, butter and margarines, cheese, pastries, sweets, and fried or fast foods.

A research team from Rush, including senior study author Prof. Morris, have found a link between adherence to the MIND diet and a slower rate of cognitive decline in individuals who previously had a stroke.

The findings were presented at the American Stroke Association International Stroke Conference 2018 in Los Angeles, CA, on Thursday.

Stroke and dementia

"We know that stroke survivors are twice as likely to develop dementia compared to the general population," explains lead study Dr. Laurel J. Cherian, a vascular neurologist and assistant professor of neurological sciences at Rush University Medical Center.

Previous work by Prof. Morris showed that even moderate adherence to the MIND diet had a positive influence on cognitive decline; in one study, the risk of developing Alzheimer's was reduced by 35 percent.

"I was really intrigued by the results of a previous MIND study, which showed that the people who were most highly adherent to the MIND diet cognitively functioned as if they were 7.5 years younger than the least adherent group," says Dr. Cherian. "It made me wonder if those findings would hold true for stroke survivors."

Dr. Cherian's study included 106 participants, who had a history of stroke. Each participant was assessed once per year to test their individual level of cognitive decline, for an average of 4.7 years.

The study subjects recorded their diet using a food frequency questionnaire, which allowed the researchers to allocate the information into three categories: high, medium, and low adherence to the MIND diet.

The team then used a linear mixed model, which accounted for age and other possible factors that could influence cognitive decline, such as sex, education, genetics, late-life cognitive activity, calorie intake, physical activity, and smoking.

Slowing down cognitive decline

According to the study team, "high adherence to the MIND diet was associated with substantially slower rate of cognitive decline in stroke survivors."

These results held true whether the model was adjusted only for the participants' age or the additional factors.

However, participants whose diet most closely resembled the Mediterranean or DASH diets — rather than the MIND diet — did not experience a slower rate of cognitive decline.

Commenting on the findings, Dr. Cherian says, "the Mediterranean and DASH diets have been shown to be protective against coronary artery disease and stroke, but it seems the nutrients emphasized in the MIND diet may be better suited to overall brain health and preserving cognition."

"Our study suggests that if we choose the right foods, we may be able to protect stroke survivors from cognitive decline," she adds.

One of the limitations of the current study is its small size. The other one is that it is observational. A larger study to validate the team's findings and assess the long-term outcomes of the MIND diet is clearly needed.

However, the results provide an encouraging starting point for individuals who have been affected by stroke.

"This is a preliminary study that will hopefully be confirmed by other studies, including research looking specifically at stroke survivors. For now, I think there is enough information to encourage stroke patients to view food as one of their most powerful tools to optimize their brain health."

Dr. Laurel J. Cherian