Cracking Down on Cheating Athletes
Chris - Someone who's been working on ways to detect if people are cheating is John Danaceau. He joins us from the Sports Medicine and Testing Lab at the University of Utah. Hello John.
John - Hello, how are you?
Chris - Very well, thank you. Welcome to the Naked Scientists. What sorts of agents have you been looking at?
John - You just mentioned on the show some of the ones that are typically looked at. We test for things like anabolic steroids both natural and synthetic. We look for stimulants, we also look for masking agents which include things like diuretics which increase urine production - help people flush out their systems if they've taken something illegal. Also, for example, there's a compound called finasteride. It's included in the masking agents but it's a steroid and metabolism regulator. It decreases the production of a compound called DHT which produces some secondary side-effects of testosterone. Those are the main ones we look for. Our lab's also working on developing a method to look at homologous blood transfusions, human growth hormone and things like that. Most of what you've been talking about we're working on in our laboratory right now.
Chris - The problem is if you take a drug which is something that's naturally found in the body anyway how do you determine that person has taken it illicitly and it's not just that they've got very high levels of that anyway?
John - There's a couple of ways. For example, if you look at testosterone. You mentioned you couldn't get it from your diet but there are synthetically produced versions of testosterone. The big difference is that almost all synthetic hormones are produced from plant material. Plant material has a difference ratio of carbon-12, which is the most abundant carbon isotope, to carbon-13. It's a naturally-occurring carbon isotope. One of the ways that you can test for that is using a carbon isotope ration mass-spectrometer. It's a method we're developing right now that most other anti-doping labs in the world have up and running. We're very close to getting our up and running right now.
Chris - What if I suddenly binged on testosterone to bulk up my muscles? What could you find and tell that I'd definitely taken something from outside my body?
John - One of the things we look at for the CIR test. We take something called the testosterone to epi-testosterone ratio or the TE ratio. Epi-testosterone is an isomer of testosterone. It has the same chemical formula but it's arranged a little differently. It comes out at a different time in the mass-spectrometry system. Most people have a TE ratio of around 1:1. They have equal amounts. There have been studies shown that some people have a little higher and a little lower but the World Anti-Doping Agency has set the TE ratio at 4:1 as a cut-off. If you have four times more testosterone than epi-testosterone that raises alarm bells and we can take that sample and investigate a little further.
Chris - What would happen if I took both? You can make both and then the ratio would be normal.
John - Exactly. You can take both however there is an upper limit, a ceiling, for epi-testosterone where I believe it's 100-200ng per ml. You can't just take both because your epi-testosterone level will be high enough that will also trigger a presumptive positive finding. Again we can further investigate to see if you've taken a synthetic version of testosterone or epi, for that matter. In addition to that you get some of the metabolites of testosterone. If we see those are elevated some of the naturals like DHT - that's another way that we'll say, 'ah this sample looks a bit suspicious.' We always see a little bit of DHT but if we see a lot that could tell us they may have been taking something and further investigate.
Chris - What proportion of athletes do you think at some time in their career have probably used something?
John - I'm not sure I'm qualified to say exactly. We have positive findings around 2% of those that come through us. One of the cornerstones of our lab is the confidentiality of the athletes so I can't really say. Obviously I can't divulge what are the exact tests that we get or what are the results that we get. They are in the low, I'd say, 1-2%. If you look on the WADA's website you'll see other laboratories have a similar percentage of positive findings. I should emphasise these are the positive findings found by the laboratory. Somebody could be doping, if they're very sophisticated, at a level where they've tried to get around the system. That happened with the THG that was developed at Balco.