For many a fashion girl, high heels are a nonnegotiable accessory for a killer outfit. And sure, we all complain about our aching feet after spending a long day in pumps, but that hasn’t deterred us from growing our beloved footwear collection—until now. Accordingly to a new study by Stanford University, researchers found that skyscraping stilettos are actually causing women to prematurely age by about 20 years due to the pressure they put on your knees. By measuring how healthy women walked in various shoe styles compared to those who stroll in heels, researchers concluded that the strain put on knees after walking in heels can lead to more trouble down the road, especially for those who are overweight. “High heel use, especially when combined with increased weight, may contribute to increased [osteoarthritis] risk in women,” the study’s authors reported. So for those who have a tendency to forgo flats, it’s officially time to reconsider—for your health.