The desire to win can be a strong one. Athletes often start looking for ways to enhance their performance, and the use of dietary supplements is one way of doing this.
However, the supplement industry is not well regulated, leading to the use of banned ingredients in many products. Moreover, these banned ingredients are not always clearly marked on the label.
The 2001 International Olympic Committee tested of 634 supplements and found that of these, 94 (14.8%) contained substances not labelled that would result in a positive doping test. Of these 94 samples, 23 contained banned, pro-hormones (building blocks), which metabolise to both nandrolene and testosterone in the body. In addition to there 94 samples, 66 others (10.4%) returned borderline results for various unlabelled substances.
A survey done on Olympic athletes at the Sydney Olympics in 2000 shows equally worrying results. 2758 of the 10 300 athletes tested for doping were questioned on their use of supplements. Here are the results:
- 569 reported nil use in 3 days before being tested
- Vitamins were used 1996 times: 880 times as individual vitamins; 73 times by injection. 1116 times as multivitamins (+ extra supplements); 17 times as injections
- Minerals were used 499 times 9253 times as multiminerals
- Proteins were used 18 times. Amino acids were used 396 times (95 times as injections). Creatin was used 316 times (911 times by injection), HMB (beta-hydroxy beta-methylbutyrate) was used 24 times
- Herbal extracts were used 345 times (95 times as ginseng)
- One athlete took 25 separate items on one day
What makes a substance prohibited?
The World Anti-doping Agency (WADA) deems a substance or method to be on the List of Prohibited Substances and Methods if it meets any two of the following criteria:
- Medical or other scientific evidence that the substance or method has the potential to enhance sports performance
- Represents an actual or potential health risk to the athlete
- Use of the substance or method violates the spirit of sport as described in the WADA code
Substances or methods are also included if WADA determines there is medical or other scientific evidence that it has the potential to mask the use of other prohibited substances and methods.
Any of the following ingredients, banned by WAD and the International Olympic Committee (IOC), can be found in supplements:
- Ephedrine/ma huang/nor-pseudoephedrine
- Pro-hormones: dehydroeiandosterone (DHEA)
- Androstenedione, androstenediol
- 19- norandrostenediol
Supplement risks versus benefits
Supplements are not always harmful. Certain supplements, if used correctly and in certain situations, can play a small but useful role in performance and could be the difference between winning and losing. Supplements should only be used to fine-tune or top-up an already optimal diet.
Why food first?
It is unlikely that supplements will ever be able to replace the value of a well-planned sports-specific diet. Here are some reasons:
- Many foods and fortified foods can be used as supplements without all the risks and expense associated with supplements. For example, skim milk powder is a good, economical source of protein, carbohydrate and calcium, and can be added to enrich or fortify different foods. Breakfast bars are another example of a real food that is practical, portable and a good source of nutrients.
- Foods contain thousands of compounds that may be biologically active, including hundreds of natural antioxidants, carotenoids, and flavonoids.
- The bio-availability (absorption and metabolism) of nutrients is generally greater in food than in supplements.
- Compared to supplements or drugs, there is no risk of toxicity or of exceeding the Upper Limits.
- Supplements are often expensive.
Who should take supplements?
If your diet is adequate, supplementation is unlikely to improve performance. Athletes who require supplementation are those whose diets are deficient in certain nutrients, vegetarians, athletes participating in aesthetic sports and following restrictive diets, athletes with medical problems and athletes exercising in extreme environments. A thorough assessment of your current diet is needed to establish any nutrient deficiencies.
However, a general multivitamin and mineral supplement would benefit most sports people, providing it constitutes no more than 100-150% of the Recommended Dietary allowance (RDA). There may be certain situations (travel or injury, for instance) when it is practical to use a short-term supplement.
Supplements than make a practical difference to the diet include meal replacement formulae, which can be included as snacks or recovery snacks (these should contain more carbohydrate than protein), carbohydrate powders (such as glucose polymers), skim milk powder, sports bars, drinks and gels.
All athletes taking supplements should ensure that each specific batches of a product has been tested for banned substances, and that each batch is certified free of illegal substances.
Source: Adapted from "Eating for Sport" by sports nutritionists Shelley Meltzer and Cecily Fuller. This new book will soon be available in leading book stores.