A study found this particular diet is associated with lower rates of Alzheimer's disease. Here's why that might be the case.
Could the MIND diet — a healthy diet heavy on vegetables and whole grains and moderate on fish, poultry and wine — prevent your risk of developing Alzheimer’s disease? Scientists who developed the diet, which is a combination of a Mediterranean and a heart-healthy diet, think so. In a 2015 study of 923 participants aged in their late 50s to late 90s, they found that strictly adhering to the MIND diet may have lowered peoples’ risk of developing Alzheimer’s by up to 53 percent.
The MIND diet stands for Mediterranean-DASH Intervention for Neurodegenerative Delay. Developed by Martha Clare Morris and her team at Rush University, the diet is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets, which have both been shown to have protective effects against cardiovascular conditions that can impact brain health.
Morris and her team of researchers gave 19 cognitive tests each year to 923 people between the ages of 58 and 98 years old who did not have Alzheimer’s when the study began. The scientists rated how closely participants followed the MIND diet by tracking intake for 10 brain-healthy food groups in participants’ food logs: green leafy vegetables, other vegetables, nuts, berries, beans, whole grains, fish, poultry, olive oil and wine.
The MIND diet recommends two or more servings of berries and at least six servings of green leafy vegetables per week, eating nuts throughout the week, beans nearly every other day, three servings of whole grains per day, at least one fish meal and two poultry meals per week and one glass of wine per day. The scientists also looked for frequency of five unhealthy food groups: red meat, butter and stick margarine, cheese, pastries and sweets, and fried/fast food.
The MIND diet recommends limiting red meats, pastries and sweets; consuming less than one tablespoon of butter and stick margarine per day, and less than one serving of cheese and fast food per week.
“The MIND diet has been shown to be
good for heart disease and other things,
so if you’re reducing other risk factors,
that by extension reduces your
–Dr. Marwan Sabbagh
The study found that even moderately following the MIND diet seemed to have benefits that protected against Alzheimer’s. Scientists ranked how well people adhered to the MIND diet, giving them a score between 0 and 15, with 15 being the best ranking. They then analyzed the relationship between diet scores and how many years it took the participants who developed Alzheimer’s to receive their diagnosis, adjusting for other factors that might increase their likelihood of developing Alzheimer’s, such as sex, education or amount of physical activity. Participants who scored the highest (8.5 to 12.5) had a 53 percent reduction in the rate of Alzheimer’s, and participants in the middle third (7 to 8), who followed the diet part-time, had a 35 percent reduction rate.
So, how does the MIND diet compare to other food regimes that may prevent dementia? While a previous study found that people who followed the MIND diet had slower cognitive decline than those who followed the Mediterranean and DASH diets, this study found that both the MIND and Mediterranean diets have similar protective effects. Scientists are still divided about the influence of lifestyle factors on risk of dementia but many believe that diet does play an important role.
“In prevention, I think the Mediterranean diet tends to hold up scientifically,” said Dr. Marwan Sabbagh, M.D., a board certified neurologist, geriatric neurologist and one of the leading experts on Alzheimer’s. “The MIND diet has been shown to be good for heart disease and other things, so if you’re reducing other risk factors, that by extension reduces your neurodegenerative risk, and there’s some hints that that approach is directly beneficial,” he said.
Morris points out that even if people are skeptical about the effects of diet on brain health, there is a proven connection between heart and brain conditions, and clear evidence that diet influences heart health. “There is a huge connection between conditions and diseases of the heart and brain,” she says. Cardiovascular conditions such as hypertension, heart disease, diabetes, stroke and obesity are associated with Alzheimer’s, says Morris, and there is strong evidence that shows diet is an important risk factor for these conditions. “That is a very ironclad, established cause and effect,” she said.
A few large studies have also looked at the MIND diet among separate populations and found that the diet led to reduced risk of dementia, Morris says. “That was very exciting to have other people confirm our finding,” she adds. Her team’s most recent study looked at one component of the MIND diet—leafy greens—and found that eating greens like kale, spinach and lettuce slows cognitive decline.
Scientists believe additional studies are needed to determine the correlation between a healthy diet and Alzheimer’s prevention. While Sabbagh said that analyses of diet and Alzheimer’s prevention suggest certain foods are beneficial, scientists need to determine whether they can prove this finding in a clinical trial.
Morris’ study was observational, making it easy to draw associations between eating certain foods and dementia risk, but difficult to determine cause and effect. While the study offers evidence that following the diet may protect against developing Alzheimer’s, other factors could have affected the reduction in the rate of Alzheimer’s disease, including lifestyle or cardiovascular-related conditions.
So, can we ward off Alzheimer’s with a nightly glass of wine and extra servings of veggies? “I wish it was that simple, but it’s not,” says Sabbagh. “You have to embrace wellness in totality. You have to diet, you have to eat right, you have to exercise. The supplements haven’t been proven, but that doesn’t mean you shouldn’t think about supplements. You have to be engaged in cognitive simulation. You have to do it all. You can’t just say, ‘I’m going to eat a terrible diet, be sedentary, and then buy every supplement in the supplement aisle, and it’ll be fine.’ It doesn’t work that way. You have to do everything,” he said.
What else can you do to support brain health? Although there is currently not enough data to determine diet and supplements’ full impact on Alzheimer’s prevention, The National Academy of Sciences convened an expert panel and conducted a meta-analysis on every piece of data on Alzheimer’s disease to determine factors that are brain-health protective.
“People are always wondering, ‘Does it really matter?’ ‘Do these things actually work?’ ‘Can you prove that there’s any benefit in doing anything?’ And the answer, finally, is yes,” said Sabbagh. “For the first time ever, [the panel from the National Academy of Sciences] has three recommendations that are shown to be brain-health protective. They are physical exercise, cognitive stimulation and blood pressure management.”
“We want to all engage in wellness and brain health.
What’s the quickest thing you can do
to alter that? It’s your diet.”
–Dr. Marwan Sabbagh
Although the panel did not give specifics on activities (Sudoku vs. a crossword puzzle, or lifting weights vs. jogging, for example), evidence suggests the three factors they identified are beneficial in preventing Alzheimer’s. The panel had insufficient data for diet and supplements because the “diet concept is still evolving,” Sabbagh said. “It’s only because they are going to take all objective scientific data and weigh it against each other, and they’re just saying, ‘There’s not enough data around diet to recommend a specific diet for brain health prevention,’” he said.
Sabbagh stressed that the diet he recommends is not prescriptive, and people should focus on the overall importance of diet. “We want to all engage in wellness and brain health. What’s the quickest thing you can do to alter that? It’s your diet,” said Sabbagh.
In three years, Morris and her team will add more data to the current research. They are working on a large randomized control trial to test whether following the MIND diet has a causal effect on slowing cognitive decline and reducing brain neurodegeneration. The team will track changes in brain volume over a three-year period, focusing on the regions most affected by Alzheimer’s. “Those results will be ready in 2021, so that is our biggest endeavor,” she said. “We have much to learn, so hopefully we’re at the beginning of good research on this topic,” she adds.
The original MIND diet study was published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.