Monday, 26 November 2012

Taking drugs in the cause of public engagement in science

A prophet is welcome in his own country! This is just a belated note to thank everyone who turned up at the Café Scientifique event in Colchester a couple of weeks ago. Café Scientifique run great popular science events and it was brilliant to give a talk in my current hometown after traipsing all over the country promoting the book. And what better place than the Love Bistro? As usual a great array of questions  - though it is always a danger when they let the clinicians in as they think they know more than the rest of us (OK in many cases they actually do, but I like to keep an aura of my own scientific mystique). Anyway I advertised live performance enhancing drug taking though pseudoephedrine, caffeine and alcohol may not have been quite what the audience was expecting. Still my demonstration of blood doping using red wine seemed to go down well. Next time I’ll inject, but drinking is so much more fun…..

So what about the science? Well taking all those drugs led me to think I really have got to see if they work. One of my undergraduate students is doing a meta-analysis on the performance benefits – or not – of pseudoephedrine, the stimulant that was banned, unbanned and then re-banned by WADA. The scientific reviews I cited in my book were not convinced of its efficacy; let’s see if the most recent data is more convincing. I’ll report back when I have the data. 

Sunday, 25 November 2012

Should veteran age grouper athletes be allowed to take testosterone?

I was recently asked to give an interview to a US web page – a link to the podcast can be found at the bottom of this blog [1]. In part their interest was in a scientific view about testosterone doping in veteran athletes. A triathlete – Kevin Moats – had failed a drug test for testosterone. Moats claimed that he was taking the drug on his doctor’s advice due to his low testosterone levels. However, he had no therapeutic use exemption (TUE) so was banned.

This is an area I should have perhaps covered more in my book. Although there is no general clinical agreement on when – or indeed if - testosterone therapy should be given to older men, it is clear that in many countries reporting to your doctor with fatigue, depression and low sex drive can get you a prescription for anabolic steroids with relative ease.

This raises a number of issues:

1 Is there a clinical need for testosterone replacement therapy?

In females there is a clear menopause and hormone replacement therapy is a commonly accepted treatment to alleviate some of the associated symptoms (though the risk/reward ratio of such a therapy is controversial). In males there is no clear menopause. It is true that sex hormone levels decline with age. However, there is no clear indication that this is associated with adverse symptoms, not whether there can be reversed by testosterone administration.  But there is clear anecdotal evidence of benefit. To get to the bottom of this, the US National Institute on Aging has recently funded a large-scale clinical trial (the T-Trial) involving 800 men age 65 and older with low testosterone levels [2].

So to answer the first question testosterone may be of clinical benefit as people get older, but the evidence is not yet clear cut.

2 Should athletes on testosterone therapy be given a therapeutic use exemption (TUE)?

In sports drug testing the absolute testosterone levels are not measured, as urinary excretion of the drug is so variable. Instead the ratio of Testosterone:Epitestosterone in the urine is measured (epitestosterone is an inactive form of the hormone that does not increase muscle mass). This ratio is normally close to 1. Steroid doping will increase the T levels, but not the E. If the T/E ratio then rises above 4 it triggers a positive test. Carbon isotope ratio (CIR) testing can then confirm whether artificial testosterone had been used (as the synthetic drug is synthesized from plant sources it behaves differently to normal human testosterone in this test). Someone on testosterone replacement therapy could therefore easily trigger a positive test even if his absolute testosterone levels were not abnormally high as he would have a high T/E ratio due to the presence of the synthetic plant-derived testosterone.

So surely a TUE would be justified? Maybe so, but there are two good arguments against this. First if raising your testosterone levels to “normal” means raising them to those of a young person, is not this in itself cheating compared to rival veteran athletes who choose not to supplement? In which case allowing a TUE might put pressure on all athletes to supplement in order to compete on a level playing field. Second, once you have the exemption it would be a simple matter to increase the amount of steroids you take. This could give rise to supraphysiological levels of anabolic steroids of the kind used  - and abused - by younger athletes. Yet the doctor’s note would forgive all. I suspect this second pragmatic, practical reason is why TUE’s in this field will be rarely – if ever – permitted.

3 Can older athletes raise their testosterone levels without failing a doping test?

A quick look at any nutritional web site will reveal a whole host of products that claim to be able to increase testosterone levels “naturally”. Maca and Tribulus are two of those in current vogue. It is true that increasing the body’s own metabolic pathways should not fall foul of the testers. However, there are two problems with this approach. First athletes should beware as many supplements contain other banned substances, either by accident or design. But secondly, and equally as important, there is no evidence that these products have any affect at all on testosterone levels. Anecdotal evidence and personal testaments are no substitute for scientific studies, which invariably show negative results [3, 4].

So to summarize: we don’t know whether testosterone is clinically necessary, using it will get you banned and there are no validated supplements that can help. As a 49-year-old fatigued male with a somewhat lower sex drive than I had as a teenager, I am tempted to say “It happens to us all as we get older: just get over it and enjoy your sport”. Or of course take the therapy and compete for fun.

(these sentiments are not of course aimed at those with very low testosterone levels caused by pathology or injury, where therapy is clearly necessary and important).

[2] The Testosterone Trial - Can testosterone treatment improve unwanted effects of aging in older men?
[3         Srikugan, L., Sankaralingam, A., and McGowan, B. (2011) First case report of testosterone assay-interference in a female taking maca (Lepidium meyenii), BMJ case reports 2011
[4]        Gauthaman, K., and Ganesan, A. P. (2008) The hormonal effects of Tribulus terrestris and its role in the management of male erectile dysfunction--an evaluation using primates, rabbit and rat, Phytomedicine : international journal of phytotherapy and phytopharmacology 15, 44-54.

Tuesday, 6 November 2012

Drugs and mixed martial arts at the Manchester Science Festival

Last week I talked at Blackwell's bookshop as part of the Manchester Science Festival (hence the dodgy photo). As usual a very keen and knowledgeable audience. Some interesting questions about drug use in pro. boxing and mixed martial arts. Here I am on side with Victor Conte, for once, about the need for more effective testing. His view is to focus on the pre fight period. For sure some consistency here would be good. But, as noted here,  as long as there is no off season testing even this might not be enough. It was a shame to see some unsubstantiated rumours about famous athletes getting an airing in the Q and A. But I guess not really surprising in the wake of the Lance Armstrong story. 

Next week on Nov 14 I get to do a hometown event in Colchester at the Minories Cafe as part of the Cafe Scientifique popular science movement. Should be fun.