Abstract
Background:
Antioxidant vitamin supplements are of benefit for those with vitamin deficiencies, but before recommending their use in healthy individuals, it is prudent for the practitioner to review the recommendations, guidelines, and policies of some of the major health leaders and medical organizations. Antioxidants, such as vitamin C, vitamin E, and beta-carotene, were purported to be a near panacea. For decades, people have been led to believe that these agents can prevent everything from cancer to heart attacks, and from strokes to cataracts, and that they can even stave off aging with a “fountain of youth pill.” Sycophants of the free radical theory have claimed that oxygen radicals can damage arteries, invoke cancer formation, blur the mind, cloud the eyes, and accelerate aging. Their conceptual solution was very appealing: cheap, readily available antioxidants would prevent or reverse aging and would stop or turn around the major diseases of mankind. It has been a number of decades since researchers started to put antioxidants through the same rigorous tests that are used to validate other theories. Under scientific conditions, the antioxidant vitamins have failed to meet the fulsome predictions of the free radical theorists. Extensive research has been compiled, and evidence from these trials is increasingly showing the lack of effectiveness of the antioxidant vitamins in retarding or reversing diseases, such as cancer, heart disease, diabetes, or Alzheimer's, and aging. A substantial number of medical organizational policy statements do not recommend the supplemental use of antioxidant vitamins, and some even recommend against their use, preferring instead a nutritious diet. The best advice appears to be to eat a balanced diet with fresh fruits and vegetables, to maintain a healthy weight, to avoid stress, and to exercise regularly.
Methods:
A systematic online review of the literature.
Results:
The following either do not recommend antioxidant vitamins or have found inconclusive evidence of their benefit:
The Swedish Council of Technology Assessment The Medical Letter National Academy of Sciences Food and Nutrition Board, Institute of Medicine The American Heart Association (AHA) Institute of Medicine of the National Academies National Heart Foundation of Australia's Nutrition and Metabolism Advisory Committee The American College of Cardiology The American Diabetes Association The American Academy of Family Physicians United States Preventive Services Task Force (USPSTF) The Oregon Health and Science University The American Cancer Society The Canadian Task Force on Preventive Health Care (CTFPHC) Food Standards Agency/The British Nutrition Foundation (BNF) The Nutrition Committee of the American Heart Association Council on Nutrition, Physical Activity, and Metabolism Quackwatch The National Cancer Institute (NCI) The AHA Scientific Position of the American Heart Association American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents The US Food and Drug Administration (FDA) The Food and Nutrition Board of the National Academy of Sciences The 2006 AHA Diet and Lifestyle Recommendations The American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention National Institutes of Health State-of-the-Science Conference The American College of Chest Physicians (ACCP) The American Heart Association Atherosclerosis, Hypertension, and Obesity in Youth Committee, Council of Cardiovascular Disease in the Young, With the Council on Cardiovascular Nursing The American College of Cardiology/American Heart Association Task Force on Practice Guidelines Scientific Statement From the American Heart Association and the American Diabetes Association The Physicians Health Study The 2008 VITAmins and Lifestyle (VITAL) study The Physicians' Health Study II Randomized Controlled Trial
Conclusions:
Until the effects of antioxidant vitamins have been proved in clinical trials that directly test their impact on major disease end points, tens of millions of Americans may be wasting their money or putting themselves at unnecessary risk. In patients who do not have a vitamin deficiency, consistent beneficial effects of the antioxidant vitamins have not been demonstrated in well-designed (randomized, placebo-controlled) clinical trials, and their widespread use by the general public is not recommended to prevent disease or to prolong the life span. Greater caution must be exercised before antioxidants are recommended to ill patients, especially those with immunosuppression, cancer, stroke, bleeding disorders, diabetes, or heart disease. Overall, a considerable number of major health organizations do not recommend the use of antioxidant vitamins, and many have issued cautionary notes regarding their casual, injudicious, or unnecessary use.