March 9, 2023 – Following the MIND or Mediterranean diet may hold back changes in the brain linked to Alzheimer’s disease by the equivalent of up to 18 years of aging, a new study suggests. Carefully following the entire diet plan wasn’t needed to get significant benefits – following just one part appeared to help keep the brain youthful.
“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 4 years younger,” study author Puja Agarwal, PhD, an assistant professor at Rush University Medical Center in Chicago, said in a statement.
For the study, researchers looked at how diet was linked to amyloid plaques and tangles in the brain, which are hallmark physical signs of Alzheimer’s. Amyloid plaques are toxic protein clumps that interfere with how brain cells communicate. Tangles refer to changes that disrupt how nutrients are transported in the brain, according to the Mayo Clinic.
Detailed in this week’s edition of the journal Neurology, the study examined the brains of 581 deceased people who had enrolled before they died and who had provided detailed information on their diets.
“When we examined the participants’ brains after autopsy, we found plaques and tangles in the brains of people with Alzheimer’s disease and older people with normal cognition,” Agarwal said. “But those who followed the diets more closely had less plaques and tangles.”
Alzheimer’s disease affects 6.5 million people ages 65 and older, the Mayo Clinic says. One early sign is forgetting recent events or conversations, but the progressive disease results in serious memory problems that limit a person’s ability to perform everyday tasks.
In the study, variations in people’s physical activity levels or whether they smoked or had circulation problems did not impact the health benefits of following the MIND or Mediterranean diet.
The Mediterranean diet refers to eating mostly fruits, vegetables, beans, nuts, healthy grains, olive oil, and fish, while limiting red meat and dairy. The MIND diet, a hybrid plan built from Mediterranean and DASH (dietary approaches to stop hypertension) diets, is a variation of the Mediterranean plan that focuses on whole grains, leafy greens and other vegetables, berries, beans, nuts, lean meats, fish, poultry, and olive oil. The MIND diet limits cheese, butter, fried foods, and sweets.
In the study, researchers found that the more green leafy vegetables someone ate, the fewer signs of Alzheimer’s disease were found in the brain. People who ate at least seven servings of leafy greens per week had brains that looked 19 years younger than the brains of people who ate greens once a week or never.
People who strictly followed the Mediterranean diet had plaque and tangle amounts in their brains similar to being 18 years younger than people in the study who had the least healthy eating patterns. Strict adherence to the MIND diet translated to plaque and tangle amounts similar to being 12 years younger than people who mostly ate unhealthy foods.
The findings are “enough for people to consider adding more of these vegetables to their diet,” said Agarwal. “Future studies are needed to establish our findings further.”
The authors cautioned that their findings fell short of proving that diet caused the slowed changes seen in people’s brains.
“While this isn’t a causal relationship, it does tell us that what we eat has an impact on our brain health, even if it’s a moderate amount” Agarwal said.