The Supplement Series: Contamination

The Supplement Series: Contamination

The use of nutritional supplements is widespread throughout both athletic and general populations, with a predicted worth of £301m in the UK last year. Despite the vast volume of supplements bought and consumed everyday, the sale, production and monitoring of ingredients in supplements remains largely unregulated. Unfortunately, this has lead to many supplements containing banned substances not declared on the label, and manufacturers exchanging expensive ingredients for cheaper fillers or substitutions.

A study conducted in 2004, by the International Olympic Committee (reference 1 below), purchased 634 non-hormonal/steroidal nutritional supplements from shops in a wide range of countries, including the UK, USA, Austria and Netherlands, and from several online shops/websites. Out of the 634 supplements tested, 94 (14.8%) contained prohormones, which are precursors to steroids, not declared on the label. From the 94 supplements that did test positive, 18.8% of those were from companies in the UK. Additionally, 9.6% of the 94 supplements that tested positive were bought from company’s that do not sell prohormones, therefore one must assume these companies obtain their products from a prohormone producing manufacturer.

A more recent study in 2013, by Newmaster and collegaues, (reference 2 below) tested 44 herbal supplements sold by 12 different companies in Canada and the USA.  They found that 59% of the herbal products contained species of plants and herbs not stated on the label. Additionally, 33% of the supplements contained contaminants and/or fillers not listed on the label. The most worrying finding was that some of the contaminants the researchers found pose serious health risks to consumers.

Both athletes and the general population should be aware that nutritional supplements may contain ingredients, such as banned substances, that are not declared on the label. Additionally, that supplements may not contain any ingredients stated on the label and instead may contain cheaper fillers, substitutes or contaminants.

Batch testing involves testing a supplement, its ingredients and manufacturing facilities, for prohibited substances and manufacturing quality standards. If possible, purchase supplements that have been batch tested through quality assurance programs, such as Informed Sport, and from trusted, recognised companies, which do not produce prohormone or unregulated supplements.




About the Author

Mark Funnell holds a BSc (Honours) degree in Sport and Exercise Science and an MSc in Sport and Exercise Nutrition from Loughborough University. He is currently working as a Performance Nutritionist for the England and Wales Cricket Board with both the England Women’s Academy and Midlands Regional Disability Cricket squads. Additionally, Mark is a graduate member of the Sport and Exercise Nutrition Register (SENr), an ISAK Level 1 Anthropometrist and a UK Anti-Doping advisor.