Can Diet Prevent Alzheimer’s and Cognitive Decline? Study Hopes to Find Out

Researchers at Rush and Harvard universities are preparing a pioneering clinical trial to evaluate the impact of diet in preventing cognitive decline and Alzheimer’s disease (AD) in older people.

The randomized Phase 3 trial (NCT02817074), titled “MIND Diet Intervention and Cognitive Decline,” will test whether a healthy diet that the researchers devised — based on a mix of the Mediterranean and DASH diet plans — can protect people from neurodegenerative ills.

With support from a $14.5 million research grant from the National Institutes of Health (NIH), the study will follow  an estimated 600 people, ages 65 to 84, for three years. Planned participants will be overweight and tending to favor suboptimal diets, two factors making them vulnerable to Alzheimer’s.

The study will take place at two different sites: Rush University Medical Center, in Chicago, and Harvard School of Public Health, in Boston. It expects to begin recruiting soon.

“We hope to determine whether a specific diet affects or prevents the development of Alzheimer’s disease,” Martha Clare Morris, ScD, a nutritional epidemiologist at Rush University and the study’s principal investigator of the study, said in a press release.

The MIND diet includes nine “brain-healthy food groups,” like chicken, fish, green leafy vegetables, berries and nuts; and five “unhealthy food groups,” namely red meat, butter and stick margarine, cheese, pastries, sweets, and fried or fast food.

Morris and her colleagues developed the MIND diet in 2015 based on research highlighting those foods and nutrients thought to affect brain health. Both the Mediterranean and DASH (dietary approaches to stop hypertension) diets have been found to positively impact the risk of cardiovascular conditions.

“While we know that there is a strong link between diet and health, intervention trials to examine whether a change in diet will help prevent Alzheimer’s disease and other dementias have been largely neglected,” Morris said. “The results of this study should help us to improve brain health by developing new dietary guidelines for clinical use and for public health education.”

The trial will compare two different diet combinations and participants will be given personalized diet guidelines, with nutritional counseling throughout, and will receive regular phone calls to check their progress, as well as in-person consultations. Participants will also have access to occasional group sessions throughout the study period.

Participants will also be asked to make on-site visits five times during the study period to assess their mental state, blood pressure, diet, physical activity, general health, and medication use. Blood and urine samples will also be collected. Within the 600 patients, 300 will be randomly scanned with brain imaging (MRI) techniques at the study’s start and its end, to evaluate the impacts of the MIND diet on the brain.

Morris and her team found in 2015 that the MIND diet could slow cognitive decline and lower a person’s risk of developing AD, even if the diet was not strictly followed. These observational studies were based on self-reports and laid the groundwork for the MIND interventional trial that is about to start.

“We devised the diet and it worked in the Chicago study,” said Morris. “The results need to be confirmed by other investigators in different populations and also through randomized trials.”

Older people with family histories of dementia, a body mass index of 25 or greater, and a poorer diet may enroll in the study. Contact and enrollment information is available on its clinical trials.gov webpage.