New evidence in the fight against Alzheimer’s sheds light on how specific diets might help protect the brain against some neurological characteristics associated with brain aging and Alzheimer’s disease.
New research published in Neurology, the peer-reviewed medical journal of the American Academy of Neurology, has found that people who follow the MIND and Mediterranean diets have fewer amyloid plaques and tau tangles than those who do not. Amyloid plaques are clumps of misfolded proteins between neurons, and tau tangles are abnormal clumps of tau proteins inside neurons. They are the two biggest brain changes associated with Alzheimer’s disease.
“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,” study author Puja Agarwal, Ph.D., of RUSH University in Chicago said in a release for the study.
The MIND and Mediterranean diet protocols are similar but not exactly the same. The Mediterranean diet calls for fruits, veggies, and nuts, with three or more servings of fish each week, while the MIND diet recommends leafy greens, berries instead of a variety of fruits, and one or more servings of fish per week. Both diets recommend a small amount of wine weekly.
For the new study, researchers at RUSH Hospital in Chicago examined data from 581 participants with an average age of 84 at study onset. Participants answered yearly survey questions regarding diet and agreed to donate their brains upon their death for study. Immediately before death, 39% of participants were diagnosed with dementia, and upon post-mortem examination, 66% were diagnosed with Alzheimer’s disease.
After reviewing the food questionnaires, researchers assigned each person a score based on rubrics specific to each of the two diets and grouped participants into three groups — highest scores, middle scores, and lowest scores. Researchers discovered that those in the high score group for the Mediterranean diet had brain ages 18 years younger than those in the low score group. High-scorers for the MIND diet had brain ages 12 years younger than those in the low-score group.
At autopsy, the research team found that those who consumed more leafy greens, roughly seven servings per week, exhibited the brain age of a person on average 19 years younger than those who reported one or fewer servings of leafy greens each week.
“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,” Agarwal said.
The majority of study participants were older white Americans, so additional research is necessary to determine if results are repeatable across demographics.
“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. “Future studies are needed to establish our findings further.”
Both diets have been associated with several health benefits. Recently, scientists found that couples who follow the Mediterranean diet have less trouble conceiving than those who don’t. Both diets have been linked to increased longevity, improved symptoms of depression, and fewer instances of chronic disease such as heart disease and cognitive decline.