Human brains sometimes develop abnormal clumps of proteins, called amyloid clumps and tangles, as a result of the ageing effects on brain tissue. These proteins are the hallmark of Alzheimer’s disease and usually interfere with thinking and problem-solving skills. In a new study, published in the Journal of Alzheimer’s Disease, researchers from Rush University Medical Center have found that older adults may benefit from a specific diet, called the MIND diet, even when they develop these protein deposits.
MIND diet stands for the Mediterranean-DASH Intervention for Neuro-degenerative Delay Diet. It is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets and focuses on the intake of plant-based foods and limiting consumption of animal products and foods high in saturated fat. This diet was initially formulated to prevent dementia and slow cognitive decline that can happen with age. It has 15 dietary components, including 10 brain-healthy food groups and five unhealthy groups.
According to the researchers, for persons to benefit from a MIND diet, they should eat at least three servings of whole grains, a green leafy vegetable and one other vegetable every other day along with a glass of wine, snack most days on nuts, have beans every other day, eat poultry and berries at least twice a week and fish at least once a week, and limit intake of unhealthy foods such as red meat, butter or margarine, cheese, pastries and sweets, fried or fast foods.
“Some people have enough plaques and tangles in their brains to have a postmortem diagnosis of Alzheimer’s disease, but they do not develop clinical dementia in their lifetime. Some have the ability to maintain cognitive function despite the accumulation of these pathologies in the brain and our study suggests that the MIND diet is associated with better cognitive functions independently of brain pathologies related to Alzheimer’s disease,” said Dr Klodian Dhana, lead author of the study and an assistant professor in the division of geriatrics and palliative medicine in the department of internal medicine at Rush Medical College.
For the study, researchers examined the associations of diet (from the start of the study until death), brain pathologies and cognitive functioning in older adults who participated in the Rush Alzheimer’s Disease Center’s ongoing Memory and Aging Project, which began in 1977 and includes people living in the greater Chicago area. The participants were all without known dementia at the start of the study and had agreed to undergo annual clinical evaluations while alive and brain autopsy after their death.
A total of 569 participants were followed and were asked to complete annual evaluations and cognitive tests to see if they had developed memory and thinking problems. Starting in 2004, participants were given an annual food frequency questionnaire about how often they ate 144 food items in the previous year. Using the results of this questionnaire, the researchers assigned each participant a MIND diet score, based on how often the participants ate specific foods.
An average of this MIND diet score, from the start of the study until the participant’s death, was used in the analysis to limit measurement error. Furthermore, seven sensitivity measures were calculated to confirm accuracy of the findings.
“We found that a higher MIND diet score was associated with better memory and thinking skills independently of Alzheimer’s disease pathology and other common age related brain pathologies. The diet seemed to have a protective capacity and may contribute to cognitive resilience in the elderly,” said Dr Dhana.
“Diet changes can impact cognitive functioning and risk of dementia, for better or worse. There are fairly simple diet and lifestyle changes a person could make that help to slow cognitive decline with aging and contribute to brain health,” he further added.
Besides the cognitive benefits of MIND diet, it also known to be positively associated with many other diseases including diabetes, Parkinson’s disease, hypertension, digestive issues and even cancer, as other recent studies have shown.