Mediterranean diet may reduce risk of dementia and Alzheimer’s disease, science shows

A diet rich in seafood, fruits, vegetables, nuts and olive oil may lower dementia risk, a new study suggests.

An analysis of data from more than 60,000 seniors revealed that choosing a Mediterranean diet cut a person’s chance of developing dementia by nearly a quarter, even in those with genes that put it at greater risk, according to the report published Monday in the medical journal. newspaper is published. journal BMC Medicine.

“The main message of this study is that, even for individuals at higher genetic risk, consuming a more Mediterranean diet may reduce the risk of developing dementia,” said the study’s lead author, Oliver Shannon, a lecturer in humanities. medicine. nutrition and aging at the University of Newcastle.

Among people whose food choices least resembled a Mediterranean diet, “about 17 in 1,000 individuals developed dementia during the study’s roughly nine-year follow-up period,” Shannon said in an email.

In contrast, among people whose food choices most closely resembled a Mediterranean diet, “only about 12 out of every 1,000 individuals developed dementia,” he added.

What is a Mediterranean Diet?

A Mediterranean diet is filled with healthy plant foods such as vegetables, nuts and legumes. It is rich in whole grains, fruits and olive oil and fish.

The people in the study also tended to eat less red or processed meats, sweets and baked goods, and drank fewer sugar-sweetened beverages, Shannon said.

Previous studies have been mixed on whether a Mediterranean diet can help prevent dementia. In fact, a study published in October that looked at the medical records of 28,025 Swedes found that the diet did not protect against dementia. In contrast, another study published in May that included nearly 2,000 older adults found that diets high in foods linked to inflammation — unlike the Mediterranean diet, which appears to be anti-inflammatory — were associated with faster brain aging, seen on MRI scans and a greater risk of developing dementia.

Choosing a Mediterranean diet reduces the risk of developing dementia by almost a quarter.Lauren Segal / The New York Times via Redux

To take a closer look at the impact of a Mediterranean diet on dementia risk, Shannon and his colleagues turned to the UK Biobank, which recruited men and women aged 4 to 69 from across England, Scotland and Wales from 2006 to 2010. The prospective study currently has more than half a million participants.

The recruits completed a touch screen questionnaire, participated in an oral interview, and provided biological samples and measures of physical function. Later, the recruits received scans, were assessed on multiple health outcomes, and provided information about their diet, some at multiple points during the study. The Biobank was able to keep track of the health of the participants via linked electronic medical records.

An added dimension to the new study was the inclusion of genetic information in the form of an Alzheimer’s risk score devised in previous research.

“The risk score is compiled from approximately 250,000 individual genetic variants that have been associated with Alzheimer’s disease, the most common form of dementia,” explains Shannon.

For the new study, the researchers focused on 60,298 participants who were in their 60s at recruitment. During an average follow-up of nine years, 882 individuals developed dementia.

When the researchers crunched their data, they found that individuals whose food consumption most closely matched the Mediterranean diet were 23% less likely to develop dementia over the years covered by the study.

The new research adds to mounting evidence that diet can affect dementia risk, even in people who are at higher risk because of their genes, said Dr. Thomas Wisniewski, professor of neurology, pathology and psychiatry and director of Alzheimer’s disease. Alzheimer’s. Research Center and Center for Cognitive Neurology at NYU Langone.

“This study with really good numbers and a fairly substantial effect size shows that it is indeed brain-protective to follow a Mediterranean diet,” Wisniewski said. “It is positive news and certainly something anyone can do with relative ease. So it is good news.”

Reducing the risk of dementia

Diet “is one of the lifestyle things I discuss with all my patients,” Wisniewski said. “The other thing we usually discuss with patients is the importance of staying physically and mentally active.”

Other important ways to reduce the risk of dementia include:

These are all interventions anyone can take to keep their brain healthy and reduce their risk of developing dementia,” says Shannon.

The new study found nearly a quarter reduction in dementia risk, Wisniewski said. “That’s a pretty big reduction in risk, doing something that’s not that challenging,” he added.

While it’s not known exactly how the Mediterranean diet may reduce dementia risk, it likely has multiple effects ranging from reducing antioxidants, helping reduce inflammation and improving the status of the microbiome, Wisniewski said.

Because there are no good drugs to treat dementia, experts have focused on lifestyle factors that may affect risk, said Dr. Emily Rogalski, a cognitive neuroscientist and professor of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine.

At this point, it’s unclear whether there will come a point when it’s too late to protect against dementia.

“But giving up and saying it’s too late is probably not the right attitude,” she said.

“We used to think that we were born with all the brain cells we would ever have and that the brain wasn’t as plastic, malleable or resilient,” Rogalski said. “We have learned over the decades that there is room for adaptation and change.”

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