By Candace Chemtob, B.S. and M.S in Human Nutrition
Turning on the TV, opening a magazine, we are bombarded by images that suggest that we need more of this and more of that. More money, more designer shoes, more horsepower, more square footage. The “more is better” mentality has morphed into a “more of a good thing, must be better” approach towards nutrition and particularly nutritional supplements.
While this approach might work in some cases, one should use caution and make educated decisions. This article will focus on dietary supplementation of antioxidants.
Antioxidants are widely misunderstood. A simple definition of an antioxidant is “a substance that inhibits oxidation or reactions promoted by oxygen, peroxides, or free radicals” (Merriam Webster Dictionary). Nutrients with antioxidant properties include vitamins (Vitamin E, C, A, lycopene, and beta-carotene), minerals (selenium, cooper and zinc), and possibly coenzyme Q10. Antioxidants can react with, and neutralize, free radicals which are highly reactive oxygen molecules. Free radicals are a byproduct of energy metabolism and are found in the environment, such as pollution and and cigarette smoke.
In the 1970s, research found that free radicals were associated with accelerated aging and increased risk of disease, such as heart disease. Antioxidants emerged as the “good” nutrients that could fight off the damaging effects of free radicals.
From the beginning, athletes were keenly interested in free radicals and antioxidants due to their role in energy metabolism. Exercise ramps up energy metabolism and leads to an increase in free radical production. Increased free radicals had been thought to cause muscle damage. For this reason, despite the lack of concrete evidence, athletes became susceptible to taking large doses of antioxidants in the form of dietary supplements (Bloomer, J. of Int’l Soc. of Sports Nutr, 2007).
The initial research on antioxidants found positive health benefits associated with increased intake. These observational studies compared subjects with low vs. high intake of antioxidants from food, not dietary supplements. Despite this, antioxidants became heavily marketed in the form of dietary supplements with the message that “more must be better.”
Twenty years later, the New England Journal of Medicine (NEJM) published a large study (29,000 Finnish men) that contradicted earlier observational studies. In this study subjects taking supplements of Vitamin E, beta carotene, or both as compared to patients without supplements were more likely to die from lung disease or heart disease. Two years later, another large (19,000 subjects) study was published by NEJM comparing patients taking vitamin A and beta carotene supplements to a control group.
Shockingly, the supplements greatly increased the risk of death from any cause (17%), cardiovascular disease (26%), and lung cancer by 4-6% after five years. Researchers were so troubled by the data, that the study was halted prematurely.
In May 2012, the Cochrane Group analyzed data from 78 studies with almost 300,000 subjects taking supplements beta carotene, vitamin A, C, E, and selenium. Their conclusion was “we found no evidence to support antioxidant supplements… Beta-carotene and vitamin E seem to increase mortality, and so may higher doses of vitamin A. Antioxidant supplements need to be considered as medicinal products and should undergo sufficient evaluation before marketing.” The National Institutes of Health warns “high-dose antioxidant supplements may be harmful in some cases. For example, the results of some studies have linked the use of high-dose beta-carotene supplements to an increased risk of lung cancer in smokers and use of high-dose vitamin E supplements to increased risks of hemorrhagic stroke (a type of stroke caused by bleeding in the brain) and prostate cancer.”
Despite overwhelming evidence that antioxidant dietary supplementation increases risk for disease and premature death, these supplements continue to be marketed and consumed by many. Unfortunately, the consumer is not protected when it comes to nutritional supplements by either the FDA nor the USDA. Confounding this, nutritional misinformation is everywhere making it near impossible for Americans to make informed decisions.
The bottom line is the protective health benefits of antioxidants can only be achieved by eating foods rich in these nutrients (e.g., fruits and vegetables). Eating a poor diet cannot be mitigated by taking a handful of supplements. The other message is that to be healthy, our bodies need to be in a state of balance, called homeostasis. If this balance is disrupted, by taking anything in “mega” doses, whether it is nutritional supplements, alcohol, drugs, calories, or anything else, we will be out of balance, and ill health effects may ensue. The key to a healthy diet, and lifestyle, is moderation. More of some things may be better, but not when it comes to your health.