- New research suggests that a certain diet may help your brain age more slowly.
- The diet is a tweak to the Mediterranean diet.
- The exact reason for this isn’t known, but here, experts share theories.
The past few years have seen a significant focus on slowing the aging process, and that includes trying to maintain brain health. New research suggests that following a certain diet can help slow down how the brain ages.
It’s called the green Mediterranean diet, and it’s a more plant-forward version of the classic Mediterranean diet. For the study, which was published in the journal Clinical Nutrition, researchers looked at data from 294 people who participated in a long-term study on diet and brain health called the DIRECT PLUS trial.
The study participants followed either a classic Mediterranean diet, a calorie-restricted Mediterranean diet, or the green Mediterranean diet, which included foods like walnuts, green tea, and Mankai, a leafy green. The researchers tracked several health metrics for the participants at the start of the study and 18 months later. They discovered that people who followed the green Mediterranean diet had lower levels of certain proteins called galectin-9 and decorin that are linked with brain aging.
Meet the experts: Iris Shai, Ph.D., study co-author, adjunct professor at Harvard University, and a professor of nutrition and epidemiology at Ben-Gurion University of the Negev; Heidi J. Silver, R.D., Ph.D., a research professor at Vanderbilt University Medical Center; David Cutler, M.D., a family medicine physician at Providence Saint John’s Health Center in Santa Monica, CA; Jessica Cording, R.D., C.D.N., author of The Little Book of Game-Changers; Scott Keatley, R.D., Ph.D., co-owner of Keatley Medical Nutrition Therapy
Ultimately, the researchers concluded that a green Mediterranean diet may slow down brain aging. Why might this be the case? Here’s what experts want you to keep in mind.
What is the green Mediterranean diet?
There are a few different interpretations of the green Mediterranean diet. But this study defined it as being low in meat and having 1,240 milligrams a day of polyphenols. (Polyphenols are plant-based compounds that help the body manage inflammation.)
The classic Mediterranean diet embraces lean meats and fish, while the green Mediterranean diet focuses more on whole grains, nuts, seeds, fruits, and vegetables.
Why might these foods help slow brain aging?
It’s not entirely clear why these foods may help slow brain aging, but there are a few theories.
A lot of it comes down to the polyphenols, according to Heidi J. Silver, R.D., Ph.D., a research professor at Vanderbilt University Medical Center. “Polyphenols are phytochemicals found in many fruits and vegetables. They have both antioxidant properties and anti-inflammatory processes,” she says. “Both of these processes have a major role in brain aging.”
The antioxidant properties of polyphenols help tamp down on oxidative stress on tissues and cells, which may lower the risk of age-related damage to cells in the brain, Silver says.
This study specifically called out polyphenol-rich foods like walnuts, green tea, and mankai, but there are plenty of other foods that are high in polyphenols. Those include berries, apples, broccoli, and dark chocolate.
Research has also found that foods rich in polyphenols may stimulate brain-derived neurotrophic factor (BDNF), which supports the growth of neurons (nerve cells) and connections between synapses in the brain. Both of those are associated with younger brains. Also worth noting: Higher BDNF levels have been linked with a slower rate of cognitive decline.
Scott Keatley, R.D., Ph.D., co-owner of Keatley Medical Nutrition Therapy, says these foods impact blood glucose, which has a big impact on the body. “Green tea, walnuts, and Mankai improve insulin sensitivity, stabilize post-meal glucose, and lower chronic inflammation. These are mechanisms that protect blood vessels in the brain and prevent the metabolic stress that accelerates neuronal loss,” he says. It’s important to note that more research is needed here to definitively say that these foods impact blood glucose management. Though some research finds polyphenols’ impact on blood sugars promising.
The foods called out in the study have their own benefits, too. “Green tea contains an amino acid called l-theanine that supports cognition and mood,” says Jessica Cording, R.D., C.D.N., author of The Little Book of Game-Changers. “For walnuts, they also contain omega-3s, which are essential for brain health.”
As for Mankai, it’s “uniquely dense in polyphenols, plant-based protein, vitamin B12, iron, and omega-3 fatty acids, and supports favorable gut microbiome and metabolic profiles,” says Iris Shai, Ph.D., study co-author, adjunct professor at Harvard University, and a professor of nutrition and epidemiology at Ben-Gurion University of the Negev.
Overall, our data suggest that adopting a green Mediterranean dietary pattern, prioritizing Mankai shakes or other leafy greens, walnuts, and several cups of green tea daily, while minimizing red and processed meat, may help preserve brain structure and function with age,” Shai says.
How else can you support healthy brain aging?
Brain health is complex and requires more than just eating a certain diet, points out David Cutler, M.D., family medicine physician at Providence Saint John’s Health Center in Santa Monica, CA.
Along with following a nutritious eating pattern, he recommends taking medications as prescribed to manage conditions like high blood pressure, diabetes, high cholesterol, and obesity. (Leaving these unmanaged may have a negative impact on your brain, Dr. Cutler points out.) “Regular exercise is also an important factor in preserving and protecting brain health,” he says.
Dr. Cutler suggests doing your best to avoid alcohol and recreational drugs like marijuana, too. Finally, he recommends staying social to keep your brain sharp.
Ultimately, Dr. Cutler points out that doing all of this isn’t just good for your brain health—it may help your overall health, too.
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