Who will win the drugs race?Catching drug cheats is essential if sports are to be conducted on a level playing field – and if deleterious health effects are to be avoided.
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Key textTo compete in the modern Olympic Games, to win gold, to stand on the rostrum as the flag is raised and the national anthem played is the dream of many. But it will come true for only a few. Only the gifted, only the dedicated, only the best will win.And maybe a few drug cheats? Modern sport is plagued by suspicions that many top athletes resort to drug-taking – doping – to enhance their performance. They use anabolic steroids, human growth hormone, erythropoietin (EPO), beta-blockers, stimulants or diuretics. While drugs such as these get a lot of publicity, they are perhaps not well understood. What do they do? What are the health risks in the short or long term? Can the drugs be detected? Here we look at three of the better known drugs in sport – anabolic steroids, human growth hormone and EPO. All are members of a family of chemicals called hormones – naturally occurring chemical messengers that regulate many of the body's functions. The main hormones are produced by glands and are transported around the body in the bloodstream. Because of their importance in the growth and development of organs and tissue, hormones are the main target in the development of performance-enhancing drugs. But, as we will see, the fact that the drugs occur naturally in the body sometimes makes detecting drug abuse difficult.
Anabolic steroids Anabolic steroids are drugs that resemble testosterone, a hormone which is produced in the testes of males and, to a much lesser extent, in the ovaries of females. Testosterone is partially responsible for the developmental changes that occur during puberty and adolescence and is also involved in controlling the rates of buildup and breakdown of the main biochemical components of all tissues, including muscle. Because testosterone and related drugs affect muscle growth, raising their levels in the blood could help athletes increase muscle size and strength. Athletes who use anabolic steroids also claim that they reduce body fat and recovery time after injury. But the androgenic (masculinising) side-effects – such as increased body hair and a deepening of the voice – are not always desirable, particularly in women. To counteract these side-effects, scientists manufacture steroids that retain their anabolic effects but have a lower androgenic effect (eg, androstenedione and nandrolone). Androstenedione was used by East German Olympic swimmers and other athletes in the 1970s and 1980s to improve their performances. It was banned by the International Olympic Committee in 1997, but is currently permitted by some other sporting bodies, such as Major League Baseball in the USA. Mark McGuire, who set a baseball home-run record in 1999, has admitted to using androstenedione (as well as the controversial food supplement creatine). Nandrolone was allegedly detected in a urine sample provided by British sprinter and Olympic gold medallist Linford Christie in 1999.
Health risks of anabolic steroids Medical experts see significant dangers in the use – and particularly the gross over-use – of anabolic steroids. Some of the effects are minor or only last while the drug is being taken; others are more serious and long-term. For example, anabolic steroids can cause high blood pressure, acne, abnormalities in liver function, alterations in the menstrual cycle in women, decline in sperm production and impotence in men, kidney failure and heart disease. They can also make both men and women more agressive.
Human growth hormone
Human growth hormone (hGH; also called somatotrophin or somatotrophic hormone) promotes physical development – particularly the growth of bone – during adolescence. It stimulates the synthesis of collagen, which is necessary for strengthening cartilage, bones, tendons and ligaments, and also stimulates the liver to produce growth factors. In adults, hGH increases the number of red blood cells, boosts heart function and makes more energy available by stimulating the breakdown of fat. It’s quite easy to see why it might enhance athletic performance. Because hGH is a protein hormone, it is possible to manufacture large amounts of hGH using recombinant DNA technology. Like anabolic steroids, hGH has a legitimate role in medicine, but it is also misused by athletes.
Health risks of human growth hormone If you believe all the hype – emanating mainly from drug manufacturers – hGH is a wonder drug that will remove wrinkles, reverse the ageing process, restore vitality and improve sleep. Nevertheless, there are some health risks. For example, too much hGH before or during puberty can lead to gigantism, which is excessive growth in height and other physical attributes. After puberty, inflated levels of hGH can cause acromegaly, a disease characterised by excessive growth of the head, feet and hands. The lips, nose, tongue, jaw and forehead increase in size and the fingers and toes widen and become spade-like. The organs and digestive system may also increase in size, which may eventually cause heart failure. Acromegaly sufferers often die before the age of 40. Excessive hGH in adults may also lead to diabetes.
Erythropoietin (EPO)
Erythropoietin – EPO – hit the headlines in 1998 when the Festina-sponsored team in cycling’s Tour de France was disqualified after being caught red-handed with large quantities of it and other banned substances. Manufactured naturally by the kidneys, EPO stimulates the production of red blood cells in bone marrow and regulates the concentration of red blood cells and haemoglobin in the blood. This is useful for athletes, since red blood cells shuttle oxygen to the cells, including muscle cells, enabling them to operate aerobically. EPO is a peptide hormone and can be produced using recombinant DNA technology. By injecting EPO, athletes aim to increase their concentration of red blood cells and, consequently, their aerobic capacity.
Health risks of EPO If EPO levels are too high the body will produce too many red blood cells, which can lead to blood clotting, heart attack and stroke. In fact, EPO has been implicated in the deaths of several athletes.
How different drugs can be detected
The issue of detection is critical to minimising the use of drugs in sport. If the regulations imposed by sporting bodies are impossible to police, we can expect that some athletes will ignore them. Alternatively, if drug-testing is quick, easy and reliable, we stand a much better chance of catching drug cheats. Unfortunately, as the science of detection advances, so too does the science of ‘masking’, or hiding, the evidence of drug abuse. A complicating factor in drug detection is that many performance-enhancing drugs occur naturally in the body. For this reason, sporting bodies usually set benchmarks – if the amount of the substance detected is above the benchmark, the athlete is said to be guilty of doping. The issue of how reliable benchmarks might be determined is addressed in Box 1: Statistical profiling – setting better benchmarks?.
Winning the drugs race? Historians point out that drugs have probably been used to enhance sporting performance for more than 2000 years, so it’s unlikely the problem will ever go away. Some commentators are even calling for the legalisation of such drugs so they can be dispensed, administered and monitored more closely. Others say the only way to ensure the health of our athletes is to stamp out drugs altogether. For now, performance-enhancing drugs are illegal, so athletes who use them are cheats. And, given the health risks associated with drug abuse, we can safely say that the race to beat the drug tests is a race nobody wins.
One possible solution is called ‘statistical profiling’. This involves gathering data on the levels of different substances in the body, during and after exercise. It would mean obtaining samples from a large number of athletes but it would also need ‘longitudinal’ data, which involve samples from the same athletes over time. With large quantities of such data, it should be possible to construct a population profile of natural levels of various substances in the body and how they vary under different exercise and dietary regimes. Such a profile would have a distribution that can be represented in a graph – a normal distribution, for example, can be represented as a bell-shaped curve, with most values occurring around the centre of the distribution, tapering off towards the upper and lower ends. From this, a probability can be attached to particular levels of substances in the body, which would help in setting reasonable benchmarks above which an individual would almost certainly be a drug cheat. Australian scientists have been developing ‘blood profiles’ for the detection of EPO use. This involves administering either EPO or a placebo to volunteer athletes and then tracking changes in the blood over time. Those athletes administered with EPO may be expected to show increased numbers of red blood cells, including a higher number of new or maturing red blood cells. The study, which initially involved 27 Canberra-based volunteers, is now being extended worldwide so that an international statistical profile can be developed.
Australasian Science March 2006, pages 17-18 Gene cheats (by Simon Grose) Looks at the possibility of genetically modified athletes competing at the Beijing Olympics.
New Scientist 10 March 2007, page 18 Cheating athletes will soon be rumbled by insulin test Describes the development of a test for synthetic insulin.
19 August 2006, pages 18-19 Only drugs can stop the sports cheats (by Michael LePage) Argues that drugs could make sport fairer and safer.
5 August 2006, page 8 Does drug testing tell the whole story? (Michael LePage) Discusses the testosterone to epitestosterone ratio test failed by two prominent US athletes.
11 February 2006, page 10 Hormone cheats risk it all for gold (by Rowan Hooper) Looks at the use of growth hormone by athletes and the risks they take to win.
2 October 2004, page 17 No cheating in the blood test (by Christie Aschwanden) A report on new drug tests that can identify athletes who have received blood transfusions in an attempt to enhance their performance.
14 August 2004, pages 6-7 Cheating is easier than you think (by David Cohen) Discusses the effect of injected testosterone on athlete performance over a short time period
1 November 2003, pages 8-9 Race on to clean up athletics (by Andy Coghlan) Describes a UK initiative to routinely test sports supplements before they go on sale.
4 October 2003, page 23 How not to stop the drug cheats (by Robert Dawson) Looks at the standardised rules on doping in sport that come into effect in 2004.
25 August 2001, page 17 Last lap (by Andy Coghlan) Describes a new lab-on-a-chip system that would make it possible for all competitors to be screened for drugs.
11 August 2001, pages 4-5 Race to the death (by Andy Coghlan) Describes the use of insulin to boost athletic performances.
16 September 2000, pages 44-46 Drugbuster (by Rachel Nowak) An interview with the director of the Australian Sports Drug Testing Laboratory.
3 June 2000, page 18 Caught red-handed (by Rachel Nowak) Australian researchers have developed a blood test to detect erythropoietin.
18 March 2000, page 6 A fair bet (by John Bonner) Australian scientists have developed a test for somatotrophin, a bodybuilding hormone that can detect artificial levels in horses, but not in humans.
15 January 2000, pages 25-29 Gene cheats (by Christie Aschwanden) Discusses the potential for genetic engineering to create 'super-athletes'.
RTD info November 2003, page 19 Sports doping: Chasing the cheats
Scientific American April 2008, pages 60-67 The doping dilemma (by Michael Shermer) Describes game theory as a means of explaining the use of drugs in sport.
July 2004, pages 36-43 Gene doping (by H. Lee Sweeney) Asks whether gene therapy could be used by athletes to enhance performance.
February 2004, pages 12-13 Doping by design (by Steven Ashley) Explains why new steroids used for performance enhancement are easy to create yet hard to detect.
Discusses why some athletes use drugs, what the major classes of drugs and their side effects are, and how drug use is tested.
Facts about substances (Australian Sports Anti-Doping Authority)
Provides information about substances including side-effects and status in the World Anti-Doping Code Prohibited List.
Drugs in sport research (National Measurement Institute, Australia)
Describes research on the detection of erythropoietin, human growth hormone, anabolic steroids and administered endogenous steroids.
Australian Broadcasting Corporation (transcripts)
Olympic challenge: transcript (28 March 2000, Frontline Scotland, BBC news, UK)
A program about the increase in positive drug tests for the banned anabolic steroid, nandrolone. Includes comments from athletes, coaches, sports administrators, manufacturers of sports supplements, medical doctors and scientists.
Do anabolic-androgenic steroids enhance sporting performance? (Medical Journal of Australia, 1997)
Reports the evidence showing that anabolic steroids increase muscle size, and probably strength.
There are 20 common amino acids: alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine. anabolic steroids. Compounds that promote the growth or synthesis (anabolism) of tissue, especially muscle. More information can be found at What are anabolic steroids? (National Institute on Drug Abuse, USA). creatine. A naturally occurring compound produced by the body, which combines with phosphate to form creatine phosphate. The combination of creatine and phosphate stores energy that can then be used for muscle contraction. hormone. A substance produced in one part of the body and carried by the blood to another part of the body where it causes a response (eg, insulin, produced by the pancreas, that promotes the uptake of glucose by body cells). For more information see The hormones of the human (Kimball's Biology Pages, USA) and The hormones (Center for Bioenvironmental Research, Tulane and Xavier Universities, USA). isotope. One of the different kinds of an atom of the same element. All atoms of an element have the same chemical properties, but the different isotopes have different weights. The different weights are because the isotopes have a different number of neutrons. For more information, see Isotopes (Carlton Comprehensive High School, Canada) mass spectrometry. A method of determining the types, and relative amounts, of ions in a sample. In a mass spectrometer, atoms or molecules in a sample are ionised by an electric beam. The ions are accelerated by an electric field and then deflected by a powerful magnet. Different ions are deflected to different degrees, so the composition of the sample can be determined. More information can be found at An introduction to mass spectrometry (University of Leeds, UK). peptide. A molecule consisting of a short chain of amino acids. Longer chains of amino acids are called proteins. placebo. An imitation of a medical treatment. This can be an inactive substance (eg, a sugar pill) or some other form of treatment which simulates a medical treatment, but should have no physiological effect. A placebo is given to a person, often as an experimental control, to enable comparison with the effects of a real drug or treatment. protein. A large molecule composed of a linear sequence of amino acids. This linear sequence is a protein's primary structure. Short sequences within the protein molecule can interact to form regular folds (eg, alpha helix and beta pleated sheet) called the secondary structure. Further folding from interaction between sites in the secondary structure forms the tertiary structure of the protein. Proteins are essential to the structure and function of cells. They account for more than 50 per cent of the dry weight of most cells, and are involved in most cell processes. Examples of proteins include enzymes, collagen in tendons and ligaments and some hormones. More information can be found at Protein structure and diversity (Molecular Biology Notebook, Rothamsted Research, UK). recombinant DNA. Genetically engineered DNA that is prepared in a laboratory by cutting up DNA molecules and splicing together specific DNA fragments. Usually the DNA that is combined is from more than one species. The spliced DNA can then be used to synthesise proteins. More information can be found at Speaking the language of recombinant DNA (Access Excellence, USA). transferrin. A type of protein that acts as the vehicle for transporting iron between different sites in the body.
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