In the longstanding debate about which gender ages better, there’s now evidence that in one regard at least, women have the edge. A new study in the Proceedings of the National Academy of Sciences finds that females have a “persistently lower metabolic brain age” than their male counterparts.

Is it hormones? Genetics? Could this be the reason that women often outlive men? Researchers aren’t exactly sure.

In plain English that means women’s brains appear younger than the brains of men of comparable age—by about four years, on average—no matter how old they actually are in chronological years. The study looked at 205 participants in all, ranging in age from 20 to 82.

What kind of advantage might having a younger brain give women? The study results may help explain why women tend to perform better on cognitive tests as they get older, lead researcher Manu Goyal, an assistant professor at Washington University School of Medicine in St. Louis, told US News. The findings also suggest that women may be better able to learn new skills and be creative later in life, Goyal told NPR.

A higher brain metabolism may also protect women from diseases like Alzheimer’s, Goyal suggested. However, some women experience a significant decline in glucose metabolism in the brain during menopause, making them more likely to develop early-onset Alzheimer’s, so the verdict is definitely still out on that one.

The brain-age findings were brought to light when a team of researchers, including Goyal, at the Washington University School of Medicine decided to see if a person’s age could be correctly determined by their brain metabolic activity. The team scanned participants to see how much oxygen and glucose were used in different parts of their brains. The levels were then used to guess the ages of the people in the study, and in most cases, the computer calculated correctly.

But the answers weren’t always precise—and when researchers separated the errors by gender, they discovered that women’s brains, on average, appeared four years younger than their actual age. This led researchers to conclude that women’s brains age more slowly than men’s.

Is it hormones? Genetics? Could this be a lot of the reason that women often outlive men? The researchers aren’t exactly sure.

But women, the next time someone asks your age and you feel like fudging it by about four years younger or so, it looks like science is on your side.

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