In recent years, multiple studies have touted the benefits of following a diet rich in antioxidant vitamins such as C and E. Now, new findings show that while antioxidant-rich foods are fine when eaten in large quantities, taking too many antioxidants in supplement form can put our health at risk.

Researchers at Cedars-Sinai Heart Institute report that many people take way too many vitamins, believing that if a little is good, a lot must be better—but that is not the case. “If you are taking 10 or 100 times the amount in a daily multivitamin, you may be predisposing your cells to developing cancer,” warns institute Director Dr. Eduardo Marbán, who led the study.