In the next few months over 14,000 Olympic and Paralympic athletes will converge on my home city for the London 2012 Olympics. The Olympic spirit stresses mutual understanding, friendship, solidarity and fair play. Yet by some estimates as many as 1,000 of these competitors could have used performance enhancing drugs to smooth their progress to the games. Some people even feel that the games are not worth watching because of this, believing that most, if not all, of the gold medals will have been gained by cheating.
What is the truth behind these fears and where are we heading in the future? To find out the answers to these questions, I made my own humble Olympic contribution. "Run, Swim, Throw, Cheat" [Oxford University Press, $29.95] is a biochemist's take on the state of sports doping. Informed by an expert, but accessible to all, or at least that is what it would say if I got to write my own book review.
Where does the 1,000 number of London Olympic cheats come? About 1% of urine and blood samples test positive for performance enhancing drugs. However, research studies indicate that about seven percent of elite athletes will admit to having doped at some point in their career, as long as the question is framed in a way that guarantees anonymity. Interestingly this is the same percent who admit to recreational drug use. Despite these alarming statistics, I am still going to be cheering on the athletes with as much fervor as ever. Nor do I feel that most athletes at the games will have gained an unfair advantage by doping. Why is this? Well of course we should all presume innocence until proven guilty. And I have some faith in the £20 million spent by the anti-doping agencies at the games. For example the introduction of "biological passports" in cycling and athletics has created a seed of doubt in these two high profile Olympic sports. The passports individualize testing and can measure a doping offence by changes in blood parameters even if the banned action itself (e.g. blood transfusion) is not detectable. These passports are not foolproof; they are also very expensive to implement and thus limited to wealthy sports. However, they have succeeded in creating a climate of fear in many where this did not exist before. Athletes and cyclists still dope, but much more carefully and therefore, probably, less effectively.
The effectiveness (or lack thereof) of many drugs is another reason why I will watch the games with relative relaxation. There are really only a few methods that are clearly performance enhancing, in that they enable athletes to perform at a level unobtainable without doping. One is the use of anabolic steroids, most especially for female athletes competing in power events. The other is blood boosting, where artificial enhancements are used to increase the amount of oxygen that can be carried by the blood. Many of the huge variety of compounds tried by athletes, including some that they swear by such as human growth hormone, seem to have relatively little performance benefit - at least at the doses that ethical review committees allow us to use on willing volunteers.
This is not to say that there are not drugs that can significantly enhance human performance. With the trained eye of the biochemist, I can identify many biochemical pathways that could in principle be manipulated to enhance performance. Many other pathways have been discovered by scientific serendipity, most notably some of the gene doping techniques that have resulted in laboratory mice that can perform supernormal feats of strength or endurance. I discuss many of these possibilities in the book, though perhaps for obvious reasons I do not go into the fine details.
So, to quote the much quoted Donald Rumsfeld, in doping there are some known knowns, many known unknowns and, I suspect, very many unknown unknowns. The question we should perhaps be asking is not why does so much doping go on, but instead why so little? Or perhaps better put, why are so few doping agents real game changers? To answer this we have to follow the money. Every single doping agent that is even remotely successful has been a prescription medicine, or minor variant thereof. However, there is no guarantee that the same molecule that enables a deficient patient to perform normally will also allow a normal person to perform supernormally. So whilst this seems to be the case for blood transfusions - topping up with extra blood really makes you run faster for longer - it does not seem, to be the case with human growth hormone therapy. Compared to cancer, vascular disease and dementia, there is relatively little pharmaceutical interest in developing treatments that increase muscle mass. So new drugs are developed rarely. Science also works best in the open. So even if the dopers had the millions of pounds to invest in trying to create a new performance-enhancing drug, the secrecy required for developing such a compound would mitigate against success.
I will leave you with an example of a success that illustrates the openness that is science at its best. Nitrate is an unlikely performance-enhancing drug. But a Swedish research group based in Stockholm recently discovered that it could increase the efficiency of aerobic running. A British group from Exeter, aware of the implications, then wanted to test whether there was a real performance benefit. They weren't able to give nitrate pills to their volunteers, but instead settled for a food rich in the compound, namely beetroot juice. The juice worked. The result is that many of the athletes competing at the London 2012 Olympics will be taking shots of concentrated beetroot juice; these are likely to be as effective as many of the drugs that are on the banned list. When taken in high doses beetroot juice turns urine a shade of purple, an interesting sight for the drug testers. It amuses me that, whilst other Olympics might be called the steroid games, London 2012 might instead gain the moniker of the beetroot juice games.