Deer Antler for Sport Performance?
Similar to the case of androstendione found in Mark McGwire’s locker, the media surrounding Ray Lewis’ miraculous recovery of a normally season-ending injury, due to a simple spray of deer antler extract, once again has stimulated huge attention to a performance supplement. In the case of McGwire, the prohormone was likely being used to mask the later admitted steroid use as research indicated no efficacy and actually an unintended side effect of increased estrodiol among males. Currently the jury is still out on whether the deer antler provides any benefit as a performance enhancing agent, purported to heal cartilage and tendon injuries more quickly while boosting strength and endurance.
The supplement is derived from male deer antlers harvested during the annual regeneration cycle. The antlers in this stage are covered in what looks like a soft fuzz. Deer antlers are the only mammalian organs that can fully grow back if lost during a fight or accident. From a performance standpoint, the ability of mammals to regenerate tissue is an exciting proposition and underscores the recent investigations with platelet-rich plasma and stem cell injections. Regenerating antlers contain sensory axons growing through the modified skin that envelopes the antler, referred to as velvet. According to PLoS One, the velvet contains growth promoters including NT-3, NGF or IGF-1 that can cause the tissue to grow one centimeter per day. Due to the high levels of growth factor in the tissue it has long been viewed in Asia as an agent with regenerating powers.
New Zealand is likely the leading exporter of deer velvet, shipping tens of millions of dollars worth of the substance to Asia and the U.S. each year. The velvet is harvested from an estimated million plus deer in New Zealand alone for its growth factor. In humans, growth hormones are naturally produced by the brain and liver, serving to regulate how the body grows. Insulin-like growth factor (IGF-1) is an anabolic hormone released in response to hypertrophy-based strength training, and is commonly associated with morphological adaptations. In supplemental form, IGF-1 has also been linked to improving cartilage damage in joints due to repetitive trauma, but studies related to growth factors are still preliminary. Furthermore, excess IGF-1 may cause tendons to rupture when muscles become too strong.
In a study published in the New Zealand Medical Journal last December, several randomized clinical trials that evaluated velvet antler supplements under varied conditions were examined. Researchers critically reviewed seven (7) trials which satisfied all inclusion criteria. The reviews analyzed the effectiveness of velvet antler for rheumatoid arthritis, osteoarthritis, sexual function, and sport performance enhancement. Methodological quality of the different studies ranged from 3-5, as measured on the Jadad scale. Of all the randomized trials only two reported any positive effects of velvet antler supplements, but researchers cited the evidence as “unconvincing”. The remaining five trials found no effect of velvet antler supplements. While more research is necessary to make formal conclusions, claims made for velvet antler supplements do not appear to be based upon rigorous research from human trials. Of all the investigations, the findings for osteoarthritis though, may hold some promise.