It turns out that oxidation-related inflammation is responsible for the lack of anabolic response to leucine in older people. In the new study, which lasted seven weeks, old rats with defective leucine metabolism were given a mixture of dietary antioxidants containing rutin (a common bioflavonoid found in fruit), vitamin E, vitamin A, zinc and selenium. The refractory leucine metabolism in the old rats was completely reversed, probably because of the antioxidant supplements. The effect was independent of leucine intake, meaning that it worked with normal leucine intake. Other studies have shown that antioxidant supplementation in older animals seems to help preserve muscle, and the effect on leucine metabolism may explain that frequently observed reaction.