Courtesy of the Gatorade Sports Science Institute

Figure 1. Exercise reduces the risk of death from Heart Disease

1 MET = Energy expended while resting    3-4 METs = Energy expended while walking very fast    5-6 Mets = Energy expended during slow running

Cardiovascular disease is a major cause of death throughout the world. Therefore, finding ways to reduce your risk of developing cardiovascular disease and protect your heart in the event of a heart attack is important. Regular exercise and dietary intake of adequate nutritional antioxidants are two lifestyle factors within our control that have been shown to provide protection for the heart (cardioprotection). Examples of activities that provide cardioprotection are running, walking, and cycling. Note in Figure 1 that exercise-related protection against cardiovascular disease follows a dose-response relationship; in other words, the risk of death from cardiovascular disease is progressively lower as exercise energy expenditure increases from 500 to 3500 kcal/week. Notice that
exercise of moderate to vigorous intensity provides the most protection against death from heart disease. Table 1 provides an overview of an exercise-prescription designed to provide cardioprotection.

Nutritional Antioxidants and Cardioprotection

Recent animal studies suggest that dietary supplementation with antioxidants (i.e., vitamin E and alpha-lipoic acid) can provide cardiac protection during a heart attack. Animal studies also show that antioxidant supplementation in drug form (i.e., unnatural antioxidants) slows the progression of coronary artery disease. Nonetheless, it is unclear if antioxidant supplementation can provide the same protection in humans. Further, given that very large doses of some antioxidants could have harmful side effects, the decision to use dietary antioxidant supplements should be approached with caution. Based on our current knowledge of antioxidants, a prudent dietary goal is to achieve the Reference Daily Intake (RDI) for major antioxidant vitamins (e.g., vitamins A, E, C) and minerals (e.g., zinc, copper, magnesium, and selenium) through a varied diet. In other words, the general rule is that most vitamin and mineral dietary requirements are best met by eating foods rather than by ingesting a supplement, and this rule should be followed for antioxidants as well. Hence, achieving the RDI for antioxidant vitamins and minerals through a diet rich in fruits and vegetables is a sound approach toward obtaining the maximum health benefits from antioxidants. Table 2 lists some important food sources of antioxidants.