GM SPORTSMEN

The recent Olympic games were a notable success for Great Britain, who placed fourth overall with 47 medals. Perhaps it is unsurprising that doping (the use of foreign substances by an athlete in order to improve their performance) has always been a problem in the competitive world of professional sports, and despite increasing the frequency of random drug tests, athletes continue to dope in full knowledge of the severe penalties should they be caught. Out of 4,500 samples taken from athletes participating at the 2008 games, six athletes tested positive and were banned from competing. With the advent of gene therapy techniques (originally developed to treat muscle wasting diseases like muscular dystrophy), it is becoming ever more likely that some athletes will experiment with gene doping, a method that is potentially harder to detect than conventional drug doping.

Under the World Anti-Doping Code, a substance is prohibited if it fulfils at least two of the following three criteria: it enhances performance, endangers health, or ‘violates the spirit of sport’. The list of banned substances is extensive, and includes steroids (used to build muscle and recover faster from training sessions), painkillers (which allow the athlete to train harder for longer before feeling the effects of muscle stress), and stimulants (which raise the heart rate and may improve performance). There are also restrictions on prescribed drugs such as corticosteroids (used to treat asthma), as well as some natural health remedies such as nutritional supplements.

Erythropoietin (EPO), a natural hormone found in the body, is widely abused in sports in order to improve aerobic performance. It acts by increasing the production of red blood cells, helping to deliver oxygen to the exercising muscles. At the moment, athletes that dope with EPO can expect only a temporary advantage over their competitors, as the glycoprotein has a short half-life and therefore requires frequent injections. If the EPO gene could be inserted into humans (it has already been successful in mice and baboons) it could potentially result in a significant and lasting increase in the expression of EPO. Another potential target is the insulin-like growth factor gene, IGF-1, which induces muscle growth when injected locally. However, not all trials have been such a success: one trial which used gene therapy for x-linked severe combined immunodeficiency disease resulted in two of the participants developing leukaemia, because the gene was inserted close to a proto-oncogene, which became activated and resulted in tumour growth and cancer.

There are of course moral and ethical concerns associated with both pharmaceutical and genetic manipulation. Athletes who fail doping tests are regarded as being cheats, and as having acted in an unsportsmanlike fashion. However, people who live at high altitudes naturally have elevated levels of EPO, which as previously discussed improves aerobic performance. So already there is a selective advantage for those living at higher elevations, and it could be argued that allowing athletes from low-lying areas to artificially increase their EPO levels would merely level the playing field. The issue of doping is clearly a complex one, and there is no simple answer as to whether testing should be even more thorough than at present, or whether the laws should be relaxed to give disadvantaged athletes a break. The development of gene therapy techniques will only exacerbate these problems, unless novel ways of testing for doping are swiftly evolved.

Tags: athletes, doping, Drug testing, Features, Olympics