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

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

An analysis of data from more than 60,000 older adults found that choosing a Mediterranean diet cut a person’s chance of developing dementia by a quarter, even among those with risk genes, according to a report published Monday in the medical journal. Journal of BMC Medicine.

“The main message of this study is that eating a Mediterranean-like diet can reduce the likelihood of developing dementia, even for people at high genetic risk,” said lead study author Oliver Shannon. Nutrition and Aging at Newcastle University.

Among those whose food choices least resembled the Mediterranean diet, “about 17 out of every 1,000 people developed dementia over the nearly nine-year study follow-up period,” Shannon said in an email.

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

What is the Mediterranean Diet?

The Mediterranean diet is full of healthy plant-based foods like vegetables, nuts, and legumes. It is rich in cereals, fruits, olive oil and fish.

People in the study typically ate less red or processed meat, sweets and pastries, and drank less sugar-sweetened beverages, Shannon said.

Previous research on whether the Mediterranean diet helps prevent dementia has been mixed. 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 of nearly 2,000 older adults published in May found that, unlike the seemingly anti-inflammatory Mediterranean diet, diets rich in pro-inflammatory foods were associated with faster brain aging seen on MRI. scan and increased risk of developing dementia.

Choosing a Mediterranean diet can reduce a person’s chance of developing dementia by a quarter.Lauren Segal / The New York Times via Redux

To look more closely at the effect of the Mediterranean diet on dementia risk, Shannon and colleagues turned to the UK Biobank, which recruited men and women aged 4 to 69 from across England, Scotland and Wales between 2006 and 2010. Currently, there are more than half a million participants in the prospective study.

Recruits completed a touchscreen questionnaire, participated in an oral interview, and submitted biological samples and measures of physical function. Later, recruits were scanned, assessed on multiple health outcomes, and provided information about their diets, some multiple times during the study. Biobank was able to track the participants’ health through linked electronic medical records.

An additional measure in the new study was the inclusion of genetic information in the form of an Alzheimer’s risk score devised in previous studies.

“The risk score was constructed using nearly 250,000 individual genetic variants associated with Alzheimer’s disease, the most common form of dementia,” explained Shannon.

For the new study, researchers focused on 60,298 participants who were over 60 years old at the time of recruitment. During an average follow-up of nine years, 882 people developed dementia.

When the researchers examined their data, they found that people whose food intake was more in line with the Mediterranean diet were 23% less likely to develop dementia over the years studied.

Dr. Thomas Wisniewski, professor of neurology, pathology and psychiatry and director of Alzheimer’s disease, says the new study provides evidence that diet can affect dementia risk even in people who are at high risk due to their genes. New York University Langone Research Center and Center for Cognitive Neuroscience.

“This study, with really good numbers and a significant effect size, shows that following a Mediterranean diet is brain-protective,” Wisniewski said. “This is good news and certainly something that everyone can easily do. So this is good news.”

Reducing the risk of dementia

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

Other important ways to reduce your risk of dementia include:

These are all interventions that everyone can take to keep their brains healthy and reduce their risk of developing dementia,” Shannon said.

A new study found that the risk of dementia was reduced by almost a quarter, Wisniewski said. “It’s a significant reduction in risk by doing something that’s not that difficult,” he added.

While it’s not clear how the Mediterranean diet reduces dementia risk, it may have many effects, from reducing antioxidants, helping to suppress inflammation and improving the state of the microbiome, Wisniewski said.

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

Currently, it is unclear whether there is a point at which it is too late to protect against dementia.

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

“We’ve always been born with all the brain cells we have, and we thought the brain wasn’t plastic, malleable or elastic,” Rogalski said. “Over the past two decades, we’ve learned that there’s room for adaptation and change.”