Brain Food: Alzheimer's and Diet

By Jane Farrell

The MIND and Mediterranean diets — both of which are rich in vegetables, fruits, whole grains, olive oil, beans, and fish — are associated with fewer signs of Alzheimer’s disease in the brains of older adults. Green leafy vegetables were associated with less Alzheimer’s brain pathology. This study, funded by the National Institute on Aging and published in Neurology, suggests these diets may help protect the brain from damage caused by Alzheimer’s.

Primarily plant-based, the MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) and Mediterranean diets are rich in nutrients important for brain health. The MIND diet features vegetables, especially green leafy vegetables such as spinach, romaine lettuce and kale; berries over other fruit; and beans, nuts, and one or more weekly servings of fish. The Mediterranean diet consists of vegetables, fruit, legumes, nuts, and at least three servings of fish each week. Both diets also include olive oil, whole grains, small amounts of wine, and limit red meat.

Previous research has shown these diets may slow cognitive decline and reduce the risk for Alzheimer’s. In this study, researchers at Rush University Medical Center examined the association of these diets with brain changes linked with Alzheimer’s.

The study involved 581 participants who agreed to donate their brains at death for dementia research. On average, the participants began the study with a first dietary assessment at an average age of 84 years. Annually, for up to more than a decade, they completed questionnaires about the food they ate in various categories. After the participants’ deaths, the researchers examined the donated brains for amyloid plaques and tau tangles, two protein hallmarks of Alzheimer’s.

The researchers also used the questionnaire information to score adherence to the two diets. Higher scores were given to participants who reported eating foods that each diet defined as healthy and reduced scores for unhealthy foods, such as red meat, and high-sugar and high-fat foods.

The brains of participants who had higher diet scores showed fewer signs of Alzheimer’s. This was primarily due to lower levels of amyloid plaques. This trend was not influenced by other lifestyle factors, including physical activity and smoking, or vascular health. There was no correlation between the diet scores and the presence of tangles.

The study’s participants were mostly White, non-Hispanic, and older. Future studies are needed with more diverse populations and to examine how different foods affect the brain and the cellular processes involved, such as inflammation. Nonetheless, the findings suggest that diet is an important lifestyle factor that needs further research as an Alzheimer’s prevention strategy.