CJ Swaby

This article appeared in Fitpro Magazine April 2008

Do supplements work? of course they do. Do all supplements work? of course not. Are supplements preferential to a healthy diet? It would be first prudent to define exactly what a supplement is. The Food Supplementations (England) Regulations 2003 (Statutory Instrument 2003 No. 1387) defines a food supplement as:

While a supplement may claim to have health benefits, it cannot legally claim to diagnose, cure, mitigate, treat or prevent a disease. Within the fitness industry common perceptions of food supplements are as ergogenic aids, which claim to enhance performance, muscle size or strength. Ergogenic aids can come in many forms. For example, carbohydrate supplements (energy drinks, gels, powders) often combined with electrolytes, are designed to enhance blood glucose levels during exercise, and sustain metabolic activity, prolonging endurance capacity. Clinical research has shown Carbohydrate ingestion during prolonged exercise effective (Claassens et al 2002).

Caffeine has developed a considerable body of research around its ergogenic effects. 3 - 6 mg/ kg caffeine ingested 1 hour prior to endurance cycling improved the time it took to fatigue at a fixed intensity (Graham and Spriet 1991; Spriet et al 1992). Caffeine has also been shown to elicit a 1.5% to 1.7% improvement while running 1500m (Wiles et al 1992; MacIntosh and Wright 1995). Caffeine has also been shown to improve force production in maximum voluntary contraction by approximately 3% (MVC; Kalmar and Caferelli 1999).

Creatine can enhance adaptation to weight training. The amount of muscle mass, muscle fiber size, and training volume performed in a single session, was shown to be greater in those that ingested creatine during training (Volek et al 1999). The majority of studies show that the performance enhancing benefit of creatine comes into its own with repeated bouts of high intensity exercise (Noakes, 2003). With regards to protein, depending on the sources you read, there is no evidence to suggest that intake greater than 1.7g/kg, has any benefit as such , even in power and strength athletes (ACSM Review 2006). This is not to say that supplementation is not beneficial, however the grade and type of protein, and activity demands may prove more significant, then excessive loading (which could induce weight gain by an increase in total calorie intake).

Multivitamins and Mineral supplements, while readily available in most food shops, are also often used medically to correct clinical deficiencies. Clinical examples of supplementation include iron preparations for anemia, and folic acid vitamin supplements in pregnancy to cite but a few. While there are toxicity issues associated with excessive intake of particular vitamins and minerals, appropriate supplementation can be safe an effective. During bone remodeling studies, calcium supplementation has shown to increase BMD (bone mineral density) by 2% (Dawson, Hughes et al 1991). When vitamin D was taken in addition to calcium supplementation, there was a reduced risk of osteoporotic hip fractures (Feskanich et al 2003). This is potentially significant for the elderly and frail who are at risk of falls and may not be getting the adequate RDA of calcium and vitamin D through their diet.

In establishing the effectiveness of supplementation, its worth considering the desired outcome of taking the supplement and suitability. Extensive analysis of all supplements is outside the scope of this debate, and is available elsewhere in other sources. Supplements can provide a measured, and convenient way to obtain macro and micro nutrients, which may not be easily obtainable through 'healthy diet', whether due to lifestyle demands, nutritional imbalances or medical conditions. While not without their side effects, supplements can enhance sport or athletic performance. Clearly supplements, are not intended to replace a 'healthy diet', indeed, one of the restrictions on sales of supplements relating to labeling in the UK stipulates that it should contain, 'a statement to the effect that food supplements should not be used as a substitute for a varied diet'(Supplementations (England) Regulations 2003 (Statutory Instrument 2003 No. 1387). Supplements are not under the same stringent controls as pharmaceutical drugs, and the effectiveness of individual supplement products and quality may vary. For anyone who wishes to supplement, it might prove prudent to seek the advice of a qualified nutritionist, to establish how best to utilize the supplement for their requirements, and any potential side effects.