Forget the fads. Here's what the science says.
KEY POINTS
Brain health issues are rising around the world, including dementia and depression.
Our food choices may significantly influence our risk for brain health issues.
The Mediterranean and MIND diets are among the most research-supported for brain health.
Both diets emphasize minimally processed foods, including fruits, vegetables, fish, nuts, olive oil, whole grains, and minimizing added sugar.
Brain health is one of the most important things we can have. Yet millions around the world already experience poor brain health, and that number is predicted to grow dramatically in the coming years. For example, it's estimated that 5 million Americans have Alzheimer's disease. Worldwide, the number of people with dementia is expected to triple to over 152 million by 2050. Additionally, cases of mental health problems (which are also brain issues) like depression appear to be on the rise, with estimates of an almost 30 percent rise in depression cases reported.
How do we help lower our chances of developing brain issues? There are a number of variables to consider ranging from sleep to exercise to stress reduction. But increasingly, research shows that we may be able to promote better brain health by using our forks. The foods we choose are the building blocks of our brains, influencing our brain circuitry. So, it’s no surprise that certain dietary patterns have been scientifically linked to better brain function. Here are two of the best-studied diets for brain health.
1. The Mediterranean diet
You've probably heard about the Mediterranean diet, as it has rapidly become one of the most popular diets for heart and overall health (it was ranked the #1 diet in 2022, according to USA Today). Unlike many fad diets you'll read about in magazines, the Mediterranean diet has good research to support its benefits. Increasingly, these include its positive effect on brain health.
The Mediterranean diet isn't always clearly defined, but it's usually understood to be a diet rich in minimally processed plant and animal foods rich in polyphenols, omega-3 fats as well as vitamins and minerals like vitamin D, Vitamin C, and vitamin E. Generally, this means eating vegetables, fruits, fish, olive oil, as well as some whole grains and poultry, with an allowance for a bit of wine. This is a diet that tends to promote a lower consumption of red meat and sugary foods. A growing number of studies link this diet to healthy brain aging.
In a 2018 paper, researchers looked at brain scans from healthy 30-to 60-year-old people, tracked their diet, and then followed up with a second brain scan two or more years later. People who stuck to a Mediterranean style of diet had evidence of healthier brain metabolism compared to those who did not, as well as lower levels of the buildup of a protein linked to Alzheimer’s disease. In a more recent paper published in the journal Neurology in 2021, higher adherence to a Mediterranean diet was linked to less brain atrophy as well as better memory.
It’s notable that, in addition to dementia, the Mediterranean diet has shown promise in other brain conditions including depression. In a set of randomized controlled trials, diets based around the Mediterranean pattern of eating were linked to improvements in mood in people with depression (1, 2, 3). In a bigger analysis, higher adherence to a Mediterranean diet has been linked to protection against depression.
2. The MIND diet
Unlike the Mediterranean diet, the MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diet has only been around for a few years. In fact, the first research publication on the MIND diet was released 2015. With many similarities to the Mediterranean diet, the MIND diet recommends eating berries, whole grains, leafy greens, nuts, fish, beans, poultry, olive oil, and also a bit of wine. It recommends against using too much butter, pastries and sugary foods, fried foods, cheese, and red meat.
In the original research on the MIND diet, scientists found that people who ate in line with the above recommendations did much better on brain tests than those whose diets were least in line with the recommendations. The difference? People who closely followed the MIND diet had cognitive scores 7.5 years younger than those who didn't. Another study showed that people who ate a MIND diet had generally lower rates of developing Alzheimer's disease.
Like the Mediterranean diet, there’s also evidence that the MIND diet may be helpful in preventing mental health conditions, specifically depression. In a 2019 publication, people who ate closest to a MIND diet had a lower risk for depression, although a smaller study found conflicting results.
What about specific foods?
Overall, much of the research around brain health and food has been more supportive of long-term healthy diets than of specific foods. Finding a sustainable, brain-healthy diet that can be followed for years will likely provide a greater net effect on brain function than eating a “superfood” on occasion. However, the top diets for brain health do tend to be high in specific nutrients. These include polyphenols (plant molecules that have been studied for their effects on health), omega-3 fats (found in fish as well as nuts and seeds), and a host of vitamins and minerals, like vitamin B12, zinc, and magnesium. Modern-day diets tend to be low in all of these nutrients and high in added sugar, which has been linked to poor brain health.
Where are good places to start?
One of the key themes in the medical literature connecting diet and brain health is the avoidance of diets that are high in processed and pre-packaged foods. Both the Mediterranean and MIND diets emphasize choosing foods that have been minimally processed. That means looking for foods without added sugar or preservatives. It also means trying to avoid refined carbohydrates (like cookies, cakes or crackers) where many of the natural nutrients have been stripped away through processing. The moderate consumption of wine (which contains polyphenols) is a component of these diets as well, although new research using brain imaging suggests that alcohol consumption may be damaging to the brain in any amount.
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