A study from the University of Dundee in Scotland shows that neither antioxidants nor aspirin pills prevent heart attacks in diabetics ( British Medical Journal, October 2008). Heart attacks occur when a plaque breaks off from the walls of a coronary artery and travels down an ever-narrowing artery to form a clot and block the flow of blood to the heart muscle. Aspirin helps to prevent clotting and therefore prevents heart attacks. Ibuprofen and other nonsteroidal pain medications block aspirin so they can increase clotting and heart attack risk in susceptible individuals.
One of the strongest risk factors for a heart attack is diabetes; 80 percent of diabetics die of heart disease. Diabetes could be such a strong risk factor for heart attacks that aspirin does not prevent it, or it may be that aspirin should be prescribed only for people with established symptomatic heart disease.
Other studies show that taking antioxidant vitamins (500 milligrams of vitamin C every day, 600 units of vitamin E every other day or 50 milligrams of beta carotene every other day) does not prevent heart attacks ( Archives of Internal Medicine, August 2007). As of today, there is no evidence that taking antioxidant pills helps to prevent heart attacks. Now many scientists think that you should aim to prevent your mitochondria from making excessive amounts of oxidants. The cells of your body have tiny chambers in them called mitochondria that help convert food to energy. When they do this, they knock of electrons from nutrients, and these extra electrons can eventually end up attached to oxygen. Electron-charged oxygen, called reactive oxygen species or free radicals, then attach to the DNA in cells to damage them and shorten life.
At this time, the only practical ways to reduce the amount of oxidants produced by mitochondria are exercise or calorie restriction with adequate nutrients. Both help the mitochondria burn food to produce fewer oxidants. In the future the same effect may be accomplished with chemicals, such as resveratrol or dichloroacetate, but studies of these substances in animals have not yet been successfully applied to humans.