Nuts can improve cognitive function. Blueberries can boost memory. Fish oil supplements may lower the risk of Alzheimer’s.
You may have seen these phrases about “brain food” spread across social media feeds. social network and health articles online. But can certain foods or diets really prevent or prevent dementia?
Experts say that while nutritional studies are notoriously challenging, there is a compelling and growing body of research that suggests that some foods and diets may offer real benefits to an aging brain. So we talked to two dozen researchers and looked at the research to better understand the links between diet and dementia.
Pillars of a good brain diet
Scientists are still not sure what causes the Alzheimer, the most common form of dementia. And there is no medication that can reverse it, said Uma Naidoo, director of nutritional and metabolic psychiatry at Massachusetts General Hospital and author of This Is Your Brain on Food. “But,” she said, “we can impact the way we eat.”
Research shows that people with certain conditions, such as heart disease, high blood pressure, obesity and diabetes, are more likely to experience age-related cognitive decline. And the risks of developing these conditions can increase with a poor diet and lack of exercise, suggesting there are things you can do to lower your chances of developing dementia, Naidoo said.
Two diets in particular, the Mediterranean diet and the MIND diet – which encourage the consumption of fresh produce, vegetables and nuts, fish, whole grains and olive oil – have shown strong protection against cognitive decline in scientific studies.
A study published in 2017 analyzed the diets and cognitive performance of more than 5,900 elderly people in the United States. U.S. The researchers found that those who adhered the most to the Mediterranean diet or the MIND diet had a 30% to 35% lower risk of cognitive impairment than those who adhered to these diets least.
“Pretty much anything that helps keep arteries healthy will reduce the risk of dementia,” said Walter Willett, professor of epidemiology and nutrition at the Chan School of Public Health in Harvard. And Ronald Petersen, a neurologist and director of the Mayo Clinic’s Alzheimer’s Research Center, agreed: “What’s good for the heart is good for the brain.”
One big change you can make to your diet, Naidoo said, is to “improve the vegetables.” Leafy greens are packed with nutrients and fiber, and some solid evidence links them to slower cognitive decline.
In a randomized controlled trial carried out in Israel and published this year, researchers performed brain scans on more than 200 people who were divided into three diet groups. They found that after 18 months, those who followed a “green” Mediterranean diet — rich in Mankai (a nutrient-packed green plant), green tea and nuts — had the slowest rate of age-related brain atrophy. People who followed a traditional Mediterranean diet were close behind. Those following the regular healthy diet guidelines — which was less plant-based and allowed more red and processed meat than the other two diets — had greater declines in brain volume.
These neuroprotective effects were especially pronounced in people aged 50 and over.
Colorful fruits and vegetables
The more colorful your plate, the better for your brain, say several experts.
In a 2021 observational study, researchers followed more than 77,000 people for about 20 years. And they found that those on diets rich in flavonoids — natural substances found in colorful fruits and vegetables, chocolate and wine — were less likely than those consuming fewer flavonoids to report signs of cognitive aging.
The MIND diet specifically points to berries, good sources of fiber and antioxidants, as foods that bring cognitive benefits. A study published in 2012 looked at more than 16,000 people aged 70 and over for more than a dozen years. It found that older women who ate the most blueberries and strawberries had slower rates of cognitive decline, sometimes with up to 2.5 years of delay.
“I don’t think there are any miracle foods, but of course it’s very good to eat fruits and vegetables,” said Allison Reiss, a member of the Alzheimer’s Foundation of America’s Memory Science and Medical Advisory Board.
Many types of seafood, particularly fatty fish, are good sources of omega-3 fatty acids, which have long been associated with better brain health and reduced risk of age-related dementia or cognitive decline.
“Fish is brain food,” said Mitchel Kling, director of the memory assessment program at the New Jersey Institute for Successful Aging at the Rowan University School of Osteopathic Medicine.
A specific omega-3 fatty acid — docosahexaenoic acid, or DHA — found in fatty cold-water fish like salmon is “the most prevalent brain fat,” said Lisa Mosconi, director of the Alzheimer’s Prevention Program at Weill Cornell Medicine. .
Our bodies can’t produce enough DHA on their own, Mosconi said. “We have to provide it from the diet, which is a strong argument for eating fish.”
According to Willett, about two to three servings a week will provide “pretty much all the benefits.”
Nuts, whole grains, pulses and olive oil
Nuts and seeds have been repeatedly linked to slower cognitive decline.
In the year 2021, in a review of 22 studies on nut consumption involving nearly 44,000 people, researchers found that people at high risk of cognitive decline tended to do better when they ate more nuts. However, the authors acknowledged that there is inconclusive evidence and some inconsistency between studies.
Another study, published in 2014, looked at nearly 16,000 women aged 70 and older between 1995 and 2001. The researchers found that women who said they consumed at least five servings of walnuts a week had better cognitive scores than those who didn’t. nuts.
Whole grains, as well as legumes such as lentils and soy, also appear to have benefits for heart health and cognitive function. In a 2017 study of more than 200 people aged 65 and over in Italy, researchers found an association between consuming three servings of legumes a week and higher cognitive performance.
And olive oil, an essential component of the Mediterranean and MIND diets, has strong links with healthy cognitive aging. A 2022 study of more than 92,000 US adults found that higher olive oil intake was associated with a 29% lower risk of dying from neurodegenerative diseases — and an 8% to 34% lower risk of overall mortality — when compared with people who never or rarely consumed olive oil.
Supplements are not substitutes
According to the experts we spoke with, there is little to no evidence that dietary supplements — including fatty acids, vitamin B or vitamin E — reduce cognitive decline or dementia.
“Supplements cannot replace a healthy diet,” Mosconi said.
A large study of nearly 3,500 seniors, for example, concluded that taking omega-3 supplements, which are often marketed as brain health aids, does not slow cognitive decline.
When it comes to supplements like fish oil, Willett said, you don’t have to “eat like a seal.” Instead, Petersen of the Mayo Clinic said the important thing is to remember the saying, “If it comes from a plant, eat it. If made on a plant [industrial]Do not eat”. / TRANSLATION BY RENATO PRELORENTZOU