Wednesday, January 30, 2013

Deer Antler Velvet, Banned Substances and Performance

If you’ve followed yesterday’s sports news, you probably read or heard about article in Sports Illustrated that highlighted a supplement company called SWATS (Sports With Alternatives to Steroids). The article titled, “Deer antler spray, radio waves and the strange lab that lured Ray Lewis and others: The zany story of two self ordained sports science entrepreneurs”, by David Epstein and George Dohrmann. This article raises some important issues about the sports supplement industry, the ways in which products are marketed and how the underlying science is used and misused. It has also thrown a prominent athlete into controversy on the eve of one of America’s biggest sporting events.

Sports supplements are nothing new. Competitors in ancient times often ate lion’s hearts in the belief that they could gain more courage, strength and stamina. Over the years, the supplement industry has grown tremendously. From companies selling safe and legal nutritional aids to websites marketing in illegal drugs, it is hard for athletes to avoid what seems to be a constant barrage of very persuasive advertising. This makes it extremely difficult for athletes to decide if these products deliver on their claims and if they can be used safely and legally.

The Sports Illustrated story emphasizes this problem. It also raises the possibility that Baltimore Ravens linebacker Ray Lewis may have used a compound purchased from SWATS known as deer antler velvet to help him rehabilitate a torn triceps tendon (he may have also used other products too but we’ll stick with the deer antler velvet story for now). While many question the benefits of supplements like deer antler velvet, using it is normally not a problem. However, deer antler velvet contains the hormone, insulin-like growth factor (IGF-1), which is on the NFL’s banned substance list. On Tuesday, Ray Lewis was confronted by accusations of doping.

Deer antler velvet is taken and extracted from the antlers of New Zealand deer. Why would anyone want to take this as a performance-enhancing supplement? Here’s the rationale. New Zealand deer regenerate their antlers at an incredible rate. The claim that these antlers grow faster than any other tissue in the animal kingdom may be a stretch but it’s probably not far from true. It seems logical if these antlers grow at a rapid rate, taking antler extract should help muscles and other tissues grow at a rapid rate, improve performance and help recover from injuries. In fact, there are several hormones found in antler velvet that may stimulate growth such as IGF-1, fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF). And, these hormones are known to be key players in tissue growth and generation. So the logic makes sense.

However, as a former coach and commentator often says, “not so fast my friend”. In the case of deer antler velvet, the amounts of IGF-1, EGF and VEGF contained in the extract are very small. The greatest amounts of these hormones are found in the blood of the deer. There, they bind to receptors on the antler cells and cause growth and replication. Only a small amount remains in the extract. Also, most hormones cannot simply enter the body by being sprayed under the tongue or digested from a pill. There are “hormone patches” (prescription medications) that deliver hormones such as estrogen through the skin. However, these patches chemically combine the hormone with a “delivery molecule” that allows it to pass through the skin, fat, and blood vessel walls to enter the blood. Without this delivery system, most hormones applied to the skin of ingested can not enter the body to exert any biological effect.

Update: From the Baltimore Sun, "Johns Hopkins professor Dr. Roberto Salvatori, however, told The Sun that even if Lewis did use deer antler velvet spray, his body would not have absorbed IGF-1." And,"there is no scientifically accepted way to deliver IGF-1 orally."

Given this, it is not surprising to find that there are no credible research studies showing any beneficial effects of deer antler velvet on performance. For example, in 2005, Canadian researchers looked at deer antler velvet supplementation combined with training in rowers and concluded, “From a practical perspective, the short-term EVA supplementation used in this study, when coupled with training does not appear to give athletes a physiological advantage to rowing performance.”  Late last year, a group from New Zealand published a review of deer antler velvet effects on a variety of supposed benefits and found, “Claims made for velvet antler supplements do not appear to be based upon rigorous research from human trials…” It should be pointed out that there are a few studies supporting this supplement. However, these studies are all critically flawed and suffer from numerous complications such as the placebo effect.

The bottom line, using deer antler velvet extract as a supplement or ergogenic aid has no research backing. While advertisers may make what seems to be a logical case for the product, the underlying assumptions are invalid and the use of science is misleading at best. Yes, deer antlers grow at a very rapid rate and yes, their extracts contain various growth factors. However, getting the very small amounts into the body and having them exert a beneficial effect is probably unlikely.

Back to Ray Lewis... It is difficult to watch an athlete who has undergone a dramatic recovery and looks to end his career on a high note, being charged with use of PEDs. This is especially true when the supplement he is accused of taking probably had no effect on his performance or the recovery of his torn triceps tendon. Stick to training and a solid diet and, in the case of injuries, follow the advice of credible medical professionals.

References

Gilbey A, Perezgonzalez JD (2012) Health benefits of deer and elk velvet antler supplements: a systematic review of randomised controlled studies, New Zealand Medical Journal, 125:80-86.

Syrotuik DG, MacFadyen KL, Harber VJ, Bell GJ (2005) Effect of elk velvet antler supplementation on the hormonal response to acute and chronic exercise in male and female rowers, International Journal of Sport Nutrition and Exercise Metabolism, 15:366-385.