Dietary Supplements: Buyer Beware

By Candace Chemtob, B.S. and M.S. in Human Nutrition

The promise of improving athletic performance easily with the help of a pill makes athletes susceptible to the claims of dietary supplements. But athletes aren’t the only Americans taking supplements. The drive to improve one’s performance, appearance, or health has created a $26.7 billion industry with more than half of all Americans taking supplements. Health professionals find this rate alarming as most consumers are uninformed and are unknowingly subjecting themselves to potentially serious health risks.

In 1994, the Dietary Supplement Health and Education Act (DSHEA) was passed allowing dietary supplement manufacturers to put products on the market without any prior safety testing. The FDA “presumes” that the products are safe. As you might expect, as a result of this lenient governmental oversight, dietary supplements tainted with hazardous additives and undeclared active medicines have reached the shelves of our health food stores, gyms, and online stores. It has been estimated that more than 50,000 adverse effects from supplements occur every year with many more going unreported. The adverse effects range from high blood pressure, to organ failure, and death.

One of the most respected medical journals, the New England Journal of Medicine, has referred to dietary supplements as “American Roulette” in a 2009 article. The article goes on to state that “contaminated supplements are an emerging risk to public health…(in a) marketplace in which manufacturers can introduce hazardous new products with virtual impunity.” These concerns have been echoed by the NCAA whose statement on banned drugs includes “many dietary supplements are contaminated with banned drugs not listed on the label…and are taken at your own risk.” College players and coaches need to be aware that taking dietary supplements may jeopardize college squash ambitions. The NCAA takes a tough stance and if a player tests positive for a banned substance, even doing so unknowingly is not an accepted excuse.

Even if you are not a college squash player, beware of products targeting athletes. Products touting improved performance have been found to also contain hazardous substances and/or undeclared medicines. Specifically, one of these additives is Androstenedione, an anabolic steroid, which works by increasing testosterone levels. It has been linked to deleterious health effects such as coronary heart disease, high blood pressure and prostrate enlargement. Other supplements have been found to contain furosemide and other diuretics that can result in dehydration and low potassium levels, both of which can decrease performance, and in the extreme be life threatening. The list of contaminants is extensive and you can access this on the Food and Drug Administration website (

Knowing now that there is a risk associated with taking dietary supplements, don’t be fooled into thinking that if the label says all “natural” that this means that the product is safe. Many of the supplements being labelled as “natural” have been found to contain contaminates. Additionally, you must also be aware that there are many substances found in nature that have deleterious health effects. One of these substances is Kava, an herbal ingredient from the South Pacific. The FDA has warned that Kava has been linked to severe liver injury, including liver failure. Other western countries have banned this ingredient from dietary supplements. To make the issue more confusing for consumers, Kava can be listed as an ingredient under other names such as Sakau, Tonga, and Piper methysticum Forst. Even a Ph.D. in chemistry might have difficulty deciphering the ingredient list on many dietary supplements.

Realizing that the risks are significant to improve athletic performance using dietary supplements, what are the benefits? Most importantly, you must understand the laws governing the labeling of dietary supplements. The labels of dietary supplements can make unsubstantiated claims for non-therapuetic benefits such as improved performance with the caveat that the label also includes a FDA approved disclaimer statement. The implication is that consumers can not rely on the manufacturer’s claims, but instead need to look elsewhere for reliable information.

This statement is a generalization, but holds true in most cases: the overwhelming majority of dietary supplements on the market have not been found to have a positive effect on athletic performance in properly conducted research studies. Given that the benefit of most supplements is dubious and the risks can be significant, don’t take dietary supplements (with the exception of vitamins and minerals, which is another topic that will be covered in a subsequent article) to improve athletic performance, or for that matter, for any reason without consulting your physician.

The bottom line is that the secret to improving athletic performance is not found in a pill. The motto “if something sounds too good to be true, it probably is” holds true for sports nutrition. Dietary supplements are no short cut to improved performance on the court.