dr gary slater - supplement use in sports - ongoing controversies

Sports Supplements…

Current Controversies

Gary Slater PhD APD Adv. ASD

Senior Lecturer (Masters of Sports Nutrition) University of the Sunshine Coast

National Performance Nutrition Coordinator ARU

Session Overview

• The current environment

• Product formulation…

– Evidence based vs marketing hype

• Inadvertent doping risk

• A help or hindrance…

– Could supplement use be impairing training

Sports Supplements

• 88% using supplements

• ‘Polysupplementation’ common

Dascombe et al. Int J Sport Nutr Exerc Metab. 13:274-280, 2010.

Majority of athletes did NOT know… •Supplement active ingredients (62%)

•Mechanism of action (57%)

•Potential side effects (57%)

•Recommended dosage (54%)

Dascombe et al. Int J Sport Nutr Exerc Metab. 13:274-280, 2010.

Dascombe et al. Int J Sport Nutr Exerc Metab. 13:274-280, 2010.

Majority of athletes used supplements for… •Health benefits

•Ergogenic potential

•On peer recommendations

Within commercial gyms… •Supplement use remains very common (85%)

•Supplementation practices vary by age & training objectives

Goston et al. Nutr. 26:604-611, 2010.

Goston et al. Nutr. 26:604-611, 2010.

Within commercial gyms… •Info primarily from readily accessible sources such as magazines

& other media, friends, health food store

• Athletes seek supplement information from readily accessible sources… – Magazines, on-line

– Fellow athletes, coaches

• Leaves athlete vulnerable to… – Ineffective protocols

– Doping

– Health implications

FitzSimmons & Kidner. J Accid Emerg Med. 15:196-197, 1998. Giampreti et al. Clin Toxicol. 47:827-829, 2009.

Prosser et al. Hum & Exper Toxicol. 28:259-262, 2009. Cons Rep. 75:24-27, 2010.

Session Overview

• The current environment

• Product formulation…

– Evidence based vs marketing hype

• Inadvertent doping risk

• A help or hindrance…

– Could supplement use be impairing training

‘Boron supplementation markedly elevated the

serum concentrations of estradiol & testosterone…’

Nielsen et al. FASEB. 1:394-397, 1987.

BSc

Session Overview

• The current environment

• Product formulation…

– Evidence based vs marketing hype

• Inadvertent doping risk

• A help or hindrance…

– Could supplement use be impairing training

Geyer et al. Int J Sports Med. 25:124-9, 2004.

Geyer et al. Int J Sports Med. 25:124-9, 2004.

Supplements & Doping

• Risks associated with supplement use are very real

• Athletes now have access to a much wider array of products domestically & internationally

• Athletes & coaches require global understanding of supplement regulation – Standards controlling labeling laws differ between countries.

In the USA, legislation allows supplement manufacturers to…

• Make claims regarding the effect of a product on the structure/ function of the body, as long as they do not claim to ‘diagnose, mitigate, treat, cure or prevent’ a specific disease

• Make claims for enhanced performance – be they valid or not

Supplements & Doping

• WADA Statement on nutritional supplements… – The ingestion of nutritional supplements pose a

special risk as they may contain or be contaminated with substances that are specifically banned

– As long as the production & sale of such supplements cannot be impeded & their purity cannot be guaranteed, the risk of testing positive in a doping test must be borne by the consumer

– ‘It was reaffirmed that the principle of an athlete’s strict liability for all substances found in his or her system needs to be maintained to protect the integrity of sport & the doping control process’

Session Overview

• The current environment

• Product formulation…

– Evidence based vs marketing hype

• Inadvertent doping risk

• A help or hindrance…

– Could supplement use be impairing training

Gomez-Cabrera et al. Am J Clin Nutr. 87:142-9, 2008.

Vitamin C supplementation

decreases training efficiency because

it prevents some cellular adaptations

to exercise

Gomez-Cabrera et al. Am J Clin Nutr. 87:142-9, 2008.

These results suggest that inhibition

of ROS attenuates some skeletal

muscle cell signalling pathways and

gene expression involved in

adaptations to exercise.

Petersen et al. Acta Physiol. 204:382-92, 2012.

Based on the contradictory evidence regarding the

effects of higher intakes of vitamin C and/or E on

exercise performance and redox homeostasis, a

permanent intake of non-physiological dosages of

vitamin C and/or E cannot be recommended to

healthy, exercising individuals.

Nikolaidis et al. Oxidat Med Cell Long. 2012.

…loading the cell with high doses of

antioxidants leads to a blunting of

the positive effects of exercise

Training…. We recommend that an

adequate intake of vitamins and

minerals through a varied and

balanced diet remains the best

approach…

Athletes should be cautioned about

taking Vitamin C chronically,

however, blackcurrant juice may

improve performance in the elite

Braakhuis et al. Eor J Sports Sci. 2013.

Athletes should be cautioned about

taking Vitamin C chronically,

however, blackcurrant juice may

improve performance in the elite

Braakhuis et al. Eor J Sports Sci. 2013.

Sports Supplements

• Athletes now have access to a much wider array of products domestically & internationally – Require global understanding of supplement regulation

• Engage significant others in education process • Consider establishment of supplement policy

– Base guidance on evidence based practice – Package & promote your system

• Recommendations may vary depending on athlete & resources available, specific goals, dietary intake etc.

• Be prescriptive…What, When, How much & Monitor

• Remain well informed – Talk with athletes – Visit supplement stores – Read both scientific & lay articles