Despite the popular notion that antioxidants, such as vitamins C and E, offer health-promoting benefits by protecting against damaging free radicals, a new study in the August 10 issue of the journal Cell reveals that, in fact, balance is the key. The researchers show in mice that an overload of natural antioxidants can actually lead the heart to failure.There is plenty of evidence about the damaging effects of oxidative stress, but “there is another side to the coin,” said Ivor Benjamin of the University of Utah, Salt Lake City. “There has been so much emphasis on free radicals to the exclusion of the potential consequences of reductants. Our study provides the first bona fide example of the role that reductive stress can play in disease.”