Americans spend several billion dollars annually on nutritional supplements. Roughly one half of the U.S. population has used some form of nutritional supplement, often on an ongoing basis.1 Supplement use extends from infancy into old age and crosses lines of gender and ethnicity. Nutritional supplements are used in attempts to balance the diet, prevent disease, ward off fatigue, enhance looks and improve performance. Supplements are also being used to augment physical appearance, enhance sexuality, delay aging and increase vitality.
In this issue of American Family Physician, Ahrendt2 raises the particularly important issue of ergogenic supplements used to enhance athletic performance. The mnemonic SOLE (safety, outcomes, legal, ethical), derived from the model proposed by Williams,3 can help physicians effectively counsel patients about the safe and appropriate use of ergogenic supplements.
Is it safe? In 1994, Congress passed the Dietary Supplement Health and Education Act (DSHEA). This act was passed partly in response to public pressure calling for an increase in the availability of natural products designed to promote health and prevent disease. These dietary supplements are not subject to the arduous drug approval process of the U.S. Food and Drug Administration (FDA) and, therefore, do not have rigorous controls on claims of safety and efficacy.
While the risks of androgenic steroid use have been known for some time,4 safety data regarding most of the currently popular ergogenic supplements are purely anecdotal. Creatine was implicated in the deaths of several collegiate wrestlers, but the cause was difficult to prove. Gamma-hydroxybutyrate has been associated with seizures and mortality and has been placed under federal restriction as a controlled substance. Most accounts of adverse events associated with ergogenic supplement use have been reported as individual cases or small case series. Relatively little prospective data are available regarding the safety of most emerging ergogenic supplements.
What is the outcome? Studies of self-reported use show that 40 to 60 percent of young athletes have taken nutritional supplements to improve performance.5 A significant number of adolescents have also experimented with anabolic-androgenic steroid use.6 Most of the information that young athletes receive regarding the effectiveness of these products comes from the lay press, anecdotal evidence or word of mouth. Athletes are often reluctant to discuss ergogenic supplement use with their physicians. The medical community is to blame for any mistrust between athletes and physicians in this arena.
During the 1970s and 1980s, a credibility gap was established when physicians repeatedly told athletes that anabolic steroids did not improve strength or add muscle mass.7 Anecdote (and eventually science) proved the medical community wrong, and athletes have subsequently been reticent to approach physicians for information regarding the effectiveness of ergogenic supplements. While some supplements may be of some benefit to some individuals in some situations, there is little doubt that most products fail to meet purported claims of efficacy. Ahrendt1 provides a useful table that summarizes the ergogenic claims of current supplements and the evidence for or against their effectiveness.
Is it legal? The list of supplements banned by the International Olympic Committee is extensive.8 Sports authorities have banned substances ranging from androstenedione to ephedrine. The rules vary among sports, and athletes continue to play “cat and mouse” with drug testing facilities to avoid detection. Some substances (such as anabolic steroids and human growth hormone) are patently illegal and are indicated for use only under the specific supervision of an attending physician for an accepted medical indication.
Is it ethical? Athletes are particularly vulnerable to the pressures of victory and are often blind to the consequences of vanity when competing to win. The recent success of Mark McGwire in baseball's home run derby has fueled an ethical debate surrounding ergogenics and sports performance. Androstenedione has been banned by the National Collegiate Athletic Association, the International Olympic Committee and the National Football League, but not by Major League Baseball. (Interestingly, the office of Major League Baseball has recently funded a study to examine androstenedione supplementation and testosterone levels in young men.9) While technically “legal” in baseball, androstenedione is a steroid precursor and the ethics of its use as a natural supplement are debatable.10
To overcome the challenges presented by the haphazard or uneducated use of ergogenic supplements, physicians should be aware of what supplements young athletes are taking, how the supplements are being taken and why they are being taken. Physicians must also know what the supplement can do to the athlete or for the athlete. The preparticipation physical examination and routine health care maintenance examinations represent excellent opportunities for family physicians to inquire about the use of ergogenic supplements and counsel patients about potential risks and benefits of supplement use.