If your food has bad fats, your body uses up its antioxidants fighting those instead of using them to protect your cells and help you live longer.

The study found that mice on a low-polyunsaturated-fat diet lived longer than those eating more unstable fats, even when all were calorie restricted. This fits with the idea that unstable fats use up the body’s protective resources, like antioxidants, leaving less for keeping cells healthy.

The study shows that antioxidants from olive oil help protect gut cells from damaged fats, which means the antioxidants are being used up to fight those bad fats—just like the claim says.