The size of your brain—like your height, blood type, and eye color—is non-negotiable. And unlike what they say about a guy with small feet, size has no effect on functionality—you can still be a genius if you have a “small” brain.
That said, you want to keep as much of your noggin as possible. About 2 percent of brain volume is lost every 10 years as we age, but recent studies show behaviors including excessive drinking, untreated depression, and a vegetarian diet, which lacks B12 vitamins primarily found in meat, dairy, and fish, can accelerate the rate at which gray matter is lost.
And while brain shrinkage doesn’t guarantee dunce-like mentality, it’s linked to decreased motor function, memory loss, dementia, and Alzheimer’s disease.
It’s no surprise that heavy drinking and a poor diet harm the brain, but the toxic effects of sadness might be a little more surprising.
According to a study published in Archives of General Psychiatry, tissue loss in the hippocampus and prefrontal cortex seems to be associated with those who report severe depression but don’t seek treatment.
“The brain damage continues over time and gets worse if left untreated,” says Kathleen Erwin, Ph.D., a psychiatrist at Scripps Memorial Hospital in Encinitas, Calif. “The longer patients stay depressed, the more brain volume they lose.”
But the good news: This study found antidepressants and talk therapy protect patients from permanent brain damage.
“If you have medical reasons for depression, managing those early is important so you don’t pick up long-term effects,” says Bill Likosky, M.D, a neurologist in Seattle. “Depression carries with it certain liabilities, one of which is decreased abilities to think, [sometimes] even after it’s passed.”
Keep your brain healthy and intact: If you show signs of depression—sleep disruption, low energy, appetite changes, or a low mood—talk to your family doctor. If you consume more than 14 alcoholic drinks a week, protect your mind by cutting back—and remember, one glass of wine is heart-healthy and provides anti-aging effects. And if you’re a vegetarian, be smart and take vitamin B supplements.