A new study from The Albert Einstein College of Medicine found that women’s brains are five times more vulnerable than men’s to injury from heading soccer balls.

Researchers performed MRI scans on 98 amateur soccer players, 49 men and 49 women, with an average of 25 years old. They measured for fractional anisotropy, which determines the movement of water molecules in one’s brain. A higher FA means better cognitive function. The study found that women showed lower FA levels across eight brain regions, compared to three in men.

“Women exhibit about five times as much microstructural abnormality as men when they have similar amounts of heading exposure,” Michael L. Lipton, professor of radiology at Albert Einstein College, wrote in a press release. “Our study provides preliminary support that women are more sensitive to these types of head impacts at the level of brain tissue microstructure.”

But more research needs to be done to establish guidelines on how to better protect female players.

“But by understanding these relationships how different people have different levels of sensitivity to heading — we can get to the point of determining the need for gender-specific recommendations for safer soccer play,” Lipton says.