Unlike medicines, which are regulated by the Medicines Control Council, there is no governing body to control and regulate the supplement industry in South Africa. As a result, many supplements may contain banned substances and there is a chance that not all the ingredients are accurately listed on the label of a supplement product.
National and international sporting bodies place the responsibility of using supplements on the sportsperson. The legal clause ‘strict liability’ means that the sportsperson is responsible for any and all substances appearing in their urine and blood. Thus, to protect sportspersons from using banned substances and to help them in the correct use of nutritional supplements, this practical guide can equip sportspersons with the tools to make decisions about nutritional supplements.
Brand names (other than food-based products) are not given since an independent regulatory body is unable to guarantee the contents of any supplement products.
Supplements in perspective
Supplement use should be individual-specific and sport-specific. Certain nutritional supplements, if used correctly, can play a small but important role in enhancing sports performance. However, it is important that the use of nutritional supplements be based on a solid foundation incorporating other factors vital in achieving peak performance. If any of these factors are lacking, then any potential performance benefit from nutritional supplements will be lost.
Sport people can make use of a classification system to establish the benefit or risk to be gained from a nutritional supplement. This system is based on the weight of scientific evidence supporting that particular supplement and has been adapted from that currently used at the Australian Institute of Sport. Note: new scientific evidence may emerge which could shift supplements between groups in the classification system.
Group A and Group B supplements are legal supplements.
Group C consists of supplements that are prohibited for use by the International Olympic Committee. This list includes pro-hormone supplements and stimulants.
Dehydroepiandrosterone (DHEA); androstenedione; androstenediol
The effect of tribulus terrestris, herbal testosterone supplements, zinc magnesium antioxidant (ZMA), ecdysterone (suma) on drug testing results are unknown.
The ingestion of testosterone precursor hormones may result in a positive doping test. This is defined as a testosterone: epitestosterone (T:E) ratio > 6:1 and constitutes a positive test.
Research has found that supplements in categories A, B may be contaminated with testosterone precursors. If testosterone prohormones are ingested inadvertently, the T:E ratio may remain elevated for up to 24 hours.
Specific examples include:
Nandrolone precursor steroids may be found in small amounts in othercommonly used supplements. If a nandrolone precursor steroid is ingested,this may be converted to nandrolone by the body. The nandrolone is brokendown to 19-norandrosterone which can be found in the urine. The athletewill have a positive drug test if the concentration is greater than 2ng.ml-1 in males and greater than 5 ng.ml-1 in females. Theurine may remain positive for 7-10 days.
Ephedrine (Ma huang – Chinese ephedra); synephrine (Citrus aurantium); ephedra; strychnine; caffeine or caffeine-containing supplements or herbs (eg. Guarana, Paullinia cupana); green tea (Camilla sinensis); kola nut (Cola acuminata), and maté (Ilex paraguayensis).
These stimulants are often found in nutritional supplements claiming to be fat burners. Read the labels carefully, particularly when products openly claim to be ephedrine free, but may contain other stimulants like synephrine.
Note: ingestion of dietary supplements containing Sida herbs (e.g.Sida cordifolio) may contain ephedrine alkaloids and thus may cause apositive drug test result.
Performance enhancing effects of caffeine are found at caffeine intakes of 1-3 mg/kg (i.e. 50-200 mg of caffeine). There is no additional benefitfrom taking a larger caffeine dose. Larger doses are associated with greater risks of side-effects (e.g. nervousness, shakiness, anxiety, heart palpitations, flushing, headaches) and urinary caffeine concentrations> 12µg.ml-1 although this may vary between individuals. Therefore keep caffeine intakes to less than 3mg/kg body weight remembering that caffeine is found in a range of foods, beverages (e.g. energy drinks, sports drinks, tea and coffee); many sports gels and drugs.
Adapted from the Australian Institute for Sport Supplement Classification System.
Conclusions and recommendations
Supplements should only be taken when there is proof that the diet cannot provide the quantities of nutrients needed. A nutritional evaluation by a dietician (with sports nutrition experience) should determine if any deficiencies are present in the diet and supplements can be supplied accordingly. This evaluation should take into account body composition goals, dietary and medical history, food practices and preferences, training and competition nutrition requirements and budgetary constraints.
Dosages of supplements need to be calculated to avoid overdose.
Individuals may respond differently to supplements and this needs to be taken into consideration. For example, 30% of athletes may not respond to creatine supplementation and supplements may be tolerated differently by different persons. Try and test diet and supplement changes well before a major competition.
Supplements required in clinical situations require a proper medical diagnosis and again should only be prescribed by the sports physician and dietician in writing. Athletes are also reminded to request written prescriptions for supplements. Fitness coaches and conditioning staff should not prescribe any supplements.
No persons under the age of 18 should take any sport-specific supplements without the advice of a sports physician or dietician.
All supplement labels should be carefully studied and the ingredients noted. Look for hidden relationships between ingredients (e.g. caffeine and guarana), unstated ingredients (e.g. fat-burning supplements that may contain hidden banned stimulant products) and avoid the prohormone supplements that are banned by sporting federations.
We recommend that for every supplement purchased the athlete request the supplier to provide a quality control certificate (this should demonstrate that the product has been tested at an independent IOC accredited laboratory and has been shown to be free of prohibited substances). The supplier should also provide legally binding documentation listing all contents of ALL the different products that they produce and should accept full liability for a positive doping test as a result of the use thereof. This guarantee document should:
Be on a company letterhead.
Be signed by management and dated.
Include contact details for the person responsible for issuing the guarantee.
Address the athlete directly by name, and not generally e.g. "To whom it may concern".
Compiled by Dr Ryan Kohler, Mrs Shelly Meltzer RD (SA), Dr Ismail Jakoet and Professor Tim Noakes for sarugby.net.
(Picture: Banned substances from Shutterstock)