The present invention provides a method of preventing or treating cardiovascular dysfunction by administering a therapeutically effective amount of (a) one or more of (i) S-adenosylmethionine or a derivative or pharmaceutically acceptable salt thereof and (ii) N-acetylcysteine or a derivative or pharmaceutically acceptable salt thereof; (b) vitamin E or a derivative or pharmaceutically acceptable salt thereof; and (c) vitamin C or a derivative or pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier.