A supplement is any product that is added to an existing formulation to address a deficiency. In sports science, the expressions dietary supplements, nutritional supplements, sports supplements, and similar terms are often used interchangeably. Whatever expression may be used, supplements are consumed for one of two reasons: nutritional benefit or to enhance performance.
Nutritional supplements are sometimes added to a diet to ensure that the athlete is consuming the proper quantities of all of the dietary macronutrients (carbohydrates, proteins, and fats) and micronutrients (chiefly vitamins, minerals, and phytochemicals) essential to both general health and optimal physical performance. An athlete may also consume supplements to obtain a training or performance advantage.
The commercial market for sport-related dietary supplements is immense. It is expected that the global revenues from the sale of such products will reach in excess of $4.5 billion by 2007. The extent of this market, coupled with uneven regulation of manufacturers and distributors of supplements directed at the athletic market, is a significant contributing factor to the problems associated with supplement contamination.
Contamination of a supplement can occur in one of two general ways. Some manufacturers adulterate their product with what they know to be illegal performance-enhancing substances to create a seemingly greater beneficial impact of the supplement on the user. A common example of supplement adulteration has been the addition of unlisted or hidden stimulants such as caffeine or ephedrine to various herbal tonics to enhance supplement effect. In other cases, protein supplements, intended for purchase by athletes seeking to build muscle or to gain weight, have been contaminated by steroids.
The second type of contamination is through the carelessness of the manufacturer. Many supplement producers do not make any of the constituent ingredients of the supplement, but instead they purchase these substances in bulk and mix them into a desired formulation, with little or no testing beforehand as to the exact chemical composition of the mixture.
A number of international studies have confirmed the likely extent of supplement contamination and the consequent risks to athletes, both in terms of their health as well as the legal consequences of an inadvertent positive doping test. An International Olympic Committee-approved laboratory at the University of Cologne, Germany, determined in a 2004 study that between 14% and 25% of the supplements that were tested were contaminated with either steroids or other illegal performance-enhancing substances.
There is no question as to the efficacy of sports drinks that are directed to rehydration, mineral and electrolyte replacement, or carbohydrate source. Similarly, a number of supplements, such as those that contain creatine, vitamin and mineral complexes, or other well-defined nutritional compounds have been proven as either beneficial to general health or mildly helpful to athletic performance. Beyond these types of supplements, there is considerable difficulty in ever being certain as to the composition of the supplement formulation, due to an absence of strict labeling guidelines throughout the world. An example is the United States Dietary Supplement Health Education Act, 1994, which does not impose specific legal obligations on the manufacturers of supplements aimed at the sports market so long as no claims are made concerning the impact on athletic performance.
A lack of knowledge as to the presence of substances such as ephedrine or steroids poses a significant health risk to the consumer. Each of these substances has a significant effect on the function of the body. Stimulants such as ephedrine are intended to increase heart rate and blood volume; for such events to occur without the athlete intending them is a dangerous circumstance. If an athlete is not aware of an anabolic agent such as steroid being consumed, the athlete would be unprepared for the many side effects of those substances, including mood swings, weight gain, and decreased sexual function.
There are also significant competitive risks posed by contaminated supplements. The World Anti-Doping Agency (WADA) has identified supplement contamination as a serious concern in sport. WADA officially consider that athletes who counter a positive doping test with the defense that they were unaware of the precise contents of the supplement due to improper labeling or contamination are guilty. In the resolution of any dispute as to whether the athlete ought to have known the composition of the supplement, WADA will seek adherence to the legal principle of strict liability as the correct standard, entirely shifting to the athlete the responsibility for what he or she ingests.