Mediterranean, MIND diets linked to fewer Alzheimer's signs in brain, study finds
People who follow a Mediterranean or MIND diet may have fewer signs of Alzheimer's disease in their brain tissue, according to a new study.
Published Wednesday in the online issue of Neurology, the medical journal of the American Academy of Neurology, the study found those who follow these plant-focused diets may have fewer amyloid plaques and tau tangles in their brain than people who don't eat this way.
A Mediterranean diet, patterned on the traditional cuisines of the region, emphasizes fresh fruits and vegetables, fish, legumes, nuts and whole grains.
The MIND diet stands for "Mediterranean-DASH Intervention for Neurodegenerative Delay" and combines many elements of the Mediterranean and DASH ("Dietary Approaches to Stop Hypertension") diets.
"These results are exciting," said study author Puja Agarwal, PhD, of Rush University in Chicago, in a press release. "While our research doesn't prove that a healthy diet resulted in fewer brain deposits of amyloid plaques, also known as an indicator of Alzheimer's disease, we know there is a relationship and following the MIND and Mediterranean diets may be one way that people can improve their brain health and protect cognition as they age."
After accounting for other factors in the 581 people they studied, researchers found "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." And for those who scored highest in following the MIND diet, their plaque and tangle amounts were similar to being 12 years younger.
While looking at specific diet components, researchers found leafy greens appeared to be the biggest asset.
"People who ate the highest amounts of green leafy vegetables, or seven or more servings per week, had plaque amounts in their brains corresponding to being almost 19 years younger than people who ate the fewest, with one or fewer servings per week," the release stated.
"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," said Agarwal.
Amyloid plaques and tau tangles in the brain are associated with the development of Alzheimer's disease, although their specific cause is not clear, and the researchers note they may also appear in some older people whose cognitive functioning was not impaired.
The Mediterranean diet focuses on "vegetables, fruit and three or more servings of fish per week," while the MIND diet prioritizes "green leafy vegetables like spinach, kale and collard greens along with other vegetables... prioritizes berries over other fruit and recommends one or more servings of fish per week," the release explains.
The study did have limitations. Participants were mostly White, non-Hispanic and older, so the results "cannot be generalized to other populations," the release states.
"Future studies are needed to establish our findings further," Agarwal added.
And while this latest study does not prove causation, it follows previous research finding a similar association between our diet and brain health.
In 2015, researchers found the MIND diet may reduce the risk of developing Alzheimer's disease by as much as 53%.
Even those who didn't stick to the diet perfectly but followed it "moderately well" reduced their risk of Alzheimer's by about a third, according to the study.