People who followed either the Mediterranean or Mediterranean-inspired MIND diets were found to have fewer signs of Alzheimer’s disease in their brains at autopsy, according to a new study on nearly 600 elderly adults.
In the observational study, a team of scientists at Rush University in Chicago monitored the diets of 581 older adults until their death. The participants had an average age of 84 at the time of enrollment, with a great majority (73 percent) of them being women.
Each of the participants agreed to have their brains studied at Rush’s neurological research center after death. When examining those brains, the scientists specifically looked for two hallmarks of Alzheimer’s disease: amyloid plaques, which are buildups of protein fragments that can disrupt the communication between nerve cells; and tau tangles, which occur when a protein called tau become abnormally shaped and can no longer do its job to transport nutrients and other essential substances in nerve cells.
The scientists then compared the number of plaques and tangles in each participant’s brain to the person’s dietary information. The comparison, according to the study, points to an association between following the Mediterranean or MIND diets with fewer indicators of Alzheimer’s disease in the brain.
This association stands even after adjusting factors such as physical activity, smoking, and vascular disease and excluding those who had mild cognitive impairment or dementia at the time they enrolled, the scientists noted.
For the study, participants received higher scores if they adhered to the Mediterranean diet by eating whole grain cereals, fruits, vegetables, legumes, olive oil, fish, and potatoes. They were given lower scores if they ate red meat, poultry, and full-fat dairy products.
Meanwhile, participants were given higher scores if they ate brain-focused MIND foods like leafy green vegetables, other vegetables, nuts, berries, beans, whole grains, fish, poultry, olive oil, and wine. They lost points for eating foods deemed unhealthy, such as red meats, butter and margarine, cheese, pastries and sweets, and fried and fast food.
“People who scored highest for adhering to the Mediterranean diet had average plaque and tangle amounts in their brains similar to being 18 years younger than people who scored lowest,” the American Academy of Neurology said in a statement on the study. “People who scored highest for adhering to the MIND diet had average plaque and tangle amounts similar to being 12 years younger than those who scored lowest.”
On top of that, the brain tissue of people who ate seven or more servings of leafy green vegetables per week looked nearly 19 years younger in terms of plaque buildup than those of people who ate just one or fewer servings per week.
The study was published on March 8 in Neurology, the flagship journal of the American Academy of Neurology.
“These results are exciting—improvement in people’s diets in just one area—such as eating more than six servings of green leafy vegetables per week, or not eating fried foods—was associated with fewer amyloid plaques in the brain similar to being about four years younger,” said Dr. Puja Agarwal, a nutritional epidemiologist at Rush and the study’s lead author.
“Our finding that eating more green leafy vegetables is in itself associated with fewer signs of Alzheimer’s disease in the brain is intriguing enough for people to consider adding more of these vegetables to their diet,” the professor added.
The researchers did note that the findings don’t prove that following a healthy diet like Mediterranean or MIND results in fewer Alzheimer’s disease plaques and tangles in the brain. They acknowledged that further investigation is needed to better understand the potential mechanisms through which diet may have a protective effect on the brain.
Alzheimer’s disease is a progressive brain disorder that slowly destroys memory and thinking skills. According to the National Institutes of Health, there are about 5.8 million people in the United States living with Alzheimer’s and related dementia.