Like your stash of leftover Halloween candy and your reserve of willpower for the day, there are a few things in life you really don’t want to run out of.
Also at the top of that list: your gray (and white) matter. Obviously your capacity to remember things and process information—abilities bestowed upon us by the robustness of our physical brains—holds a prize spot way higher up than those fun-size Snickers (at least, let’s hope).
For a while now, researchers have known that following a Mediterranean diet—one heavy on whole grains, fresh produce, and fatty fish and lower in red meat and dairy—seems to ward off signs of looming cognitive decline. But in a new study published in the journal Neurology, researchers examined the effect of the diet “on the brain itself,” says lead author Yian Gu, PhD, assistant professor of neuropsychology at Columbia University, “rather than clinical symptoms.”
Gu and her colleagues wanted to find out how the Mediterranean diet confers its cognitive benefits, and in their research, the eating plan seems to be linked with a physically bigger brain. So much bigger, in fact, that sticking to the diet prevents the amount of decline researchers would expect to see naturally occur with 5 years of aging.
The researchers analyzed food questionnaires from 674 adults without dementia who, at 65 and older, were part of ongoing aging research. Each person was scored on their intake of 9 components of the Mediterranean diet: veggies, legumes, whole grains, fish, fruit/nuts, monounsaturated fats, little red meat, little dairy, and moderate alcohol consumption. They were awarded one point for each if they ate more of the good stuff or less of the bad stuff than the average person.
After MRI brain scans, the researchers found that the 304 people who scored from 5-9 had bigger brain volume than the 370 who scored from 0-4. Those Mediterranean eaters had on average 13.11 milliliter larger total brain volume, 5 milliliter larger gray matter volume, the part of our brains that contains all our synapses, and 6.41 milliliter larger white matter volume, which connects different areas of gray matter.
“Age so far is the most important factor contributing to brain shrinkage in older people,” Gu says. “The difference between the high- and low-scoring Mediterranean diet groups is similar to the brain size difference between a 70 year old and a 75 year old.”
Even just getting 3 to 5 ounces of fish a week and lowering red meat intake to 100 grams (roughly a quarter-pounder) a day or less offered a protective effect to the tune of 3 to 4 years of aging. “When gray and white matter shrinks, you basically can’t process information, you get more forgetful, memory starts to become impaired,” says cardiologist Michael Ozner, author of The Complete Mediterranean Diet . “As a result, your risk of Alzheimer’s disease increases.”
The Mediterranean way of eating is in stark contrast to the more traditional American diet. “I call it the ‘toxic American diet’—highly processed, calorie-dense, and nutrient-depleted,” Ozner says. While red meat’s not completely off the table in Mediterranean eating, he says, it should probably be reserved for special occasions. The traditional Mediterranean diet was low in red meat not because our ancestors knew one day it would be added to the World Health Organization’s list of carcinogens, but simply because they couldn’t afford it. “They’d have veal or lamb on birthdays or at weddings,” he says.
We don’t entirely understand how the Mediterranean di