Sports stars risk more than disgrace when they attempt to enhance their performance with drugs. Some atheletes have paid the ultimate price. Eoin Burke-Kennedy reports
The main argument against the use of drugs in sport is that it harms athletes unnecessarily.
But advocates of more liberal doping laws claim that modern performance-enhancers, if used responsibly, have only temporary side-effects, at worst.
They say that using synthetic hormones like EPO (Erythropoietin) may be no different than training at altitude or that commonly abused stimulants like ephedrine are found in over-the-counter cold remedies.
Even the level of testosterone found in Ben Johnson's Seoul sample was substantially less than doctors have prescribed as a male contraceptive. The argument goes that in a world inured to drug use the war on doping is unwinnable and the laws should be liberalised accordingly.
But does the balance of medical evidence back up this up?
In February 2004 Italian cyclist Marco Pantani was found dead in his hotel bedroom after suffering a heart attack. Although an autopsy result showed the former Tour de France winner died from a cocaine overdose he was the eighth professional cyclist in 13 months to suffer a heart attack. Four of them were under the age of 24.
While conclusive epidemelogical evidence is thin on the ground medical experts overwhelmingly blame the increased use of performance enhancing drugs like EPO.
By stimulating the formation of red blood cells in the body, EPO increases the supply of oxygen to muscles - useful in endurance events like cycling. But at certain levels it causes blood thickening which affects the rate of blood flow causing, in some instances, strokes and heart attacks.
In his most recent book, French cycling expert Jean-Francois Quinet estimates that up to 80 professional cyclists may have died from doping during the 1980s and 1990s.
Dr Joe Comiskey, consultant physician at the Blackrock Clinic, says the notion that athletes using drugs are getting away with little or no side-affects is simply not true.
He says EPO is most typically used in the clinical management of anemia associated with chronic kidney problems. "The problem is you can get an overshoot on the haemoglobin which can cause strokes or heart attacks. We believe this is what is happening to cyclists," he says.
Comiskey, who is on the International Olympic Committee's Medical Commission, says an obvious indicator of EPO use is the hematocrit level - the percentage of blood that is composed of red blood cells.
"In cross-country skiers we have observed the average hematocrit level rise from 14.6 to 16.5 grammes in the last 10 years.
"We cannot say for definite that this is solely down to EPO but the suspicion is there," says Comiskey.
If positive dope tests are anything to go by the most commonly abused substances by athletes are synthetic testosterones.
The latest designer variant THG (tetrahydrogestrinone) is at the centre of a major investigation in the US involving 100 metres world record holder Tim Montgomery and triple Olympic gold medallist Marion Jones.
The steroid first came to light in 2003 after a syringe containing traces of the steroid was sent anonymously to the US Anti-Doping Agency. The substance closely resembles trenbolone, a controlled substance used to bulk up cattle.
Testosterone works as an anabolic agent driving the development of muscle tissue and is typically associated with power events such as sprinting and weight-lifting.
In 2000 two former East German sports officials were charged with the "bodily harm" of 142 women who were given anabolic steroids unknowingly.
The women testified to having suffered hormonal disturbances, developed secondary sexual characteristics such as excessive body hair, acne and deep voices, as well as liver and kidney problems. Several women claimed they were still suffering from menstrual and gynaecological problems. In one case Heidi Krieger, the 1986 European shot-put champion, said she had been forced to undergo a sex change operation because of the male hormones given to her during training in the 1980s.
In the same year the former doctor of the East German swimming team was convicted of giving drugs to athletes without telling them.
Two former swimming champions said the drugs led to congenital birth defects, including clubbed feet, among their children.
Comiskey says: "We are now finding an abnormality of serum lipids in the blood of athletes exposed to high levels of testosterone.
"This is resulting in premature vascular disease with increased cholesterol laid down in ex-athletes - some of whom are still in their 30s," he says.
Dr Conor O'Brien, former head of the Irish Anti-Doping Committee and a consultant physician in the Blackrock Clinic, says while anabolic agents increase muscle bulk they also inadvertently expand the size of the heart, since the heart itself is a muscle.
O'Brien says an anabolically-abused heart is much "bigger and floppy" than a normal heart and exhibits a pathology similar to hypertrophic cardiomyopathy where the wall of the heart thickens.
This condition is more commonly associated with long term alcohol abuse, he says.
O'Brien believes the majority of people peddling performance-enhancers do not have any detailed knowledge of the "pharmacology or the side effect profile of these substances".
Often the substances are contaminated because they have not gone through an appropriate pharmaceutical process, he says.
In the early 1980s, several cases of Creutzfeldt-Jakob Disease (CJD) developed because of contaminated Human Growth Hormone (HGH) taken from the pituitary glands of cadavers.
O'Brien cites the case of US Football star Lyle Alzado who died in 1992 from a rare brain tumour aged 43. Alzado admitted to taking large amounts of growth hormone. An autopsy showed the tumour that killed him contained not only human tissue but animal tissue from cats and dogs which had been growing inside his head.
"To suggest that these agents do not have serious side-effects is pretty much nonsense," O'Brien says.
In 2004 the World Anti-Doping Agency (WADA) took caffeine, pseudoephredrine and the majority of other stimulants off its banned substance list. In the words of one member the agency was "chasing shadows" in looking for these substances when the focus should have been on the drugs that are killing people like EPO, anabolic steroids and HGH.
But the move to delist stimulants comes at a time when new research suggests that they may have an arrhythmogenic effect on the body or in other words cause alterations in the natural electricity of the heart.
Just last week the WADA said it was going to consider putting caffeine tablets back on the banned substance list after several Australian athletes, including national rugby captain George Gregan, admitted to taking them. A therapeutic dose of caffeine for instance would be the equivalent of 12 cups of percolated coffee over a short period and would need to be taken in tablet form.
A 2003 study published in the Italian Heart Journal found that performance enhancing drugs including stimulants disrupted the normal rhythm and rate of the heart and may be associated with sudden death in athletes.
O'Brien says: "If you are taking these agents and then doing vigourous exercise - now you have a major problem of something happening when you are out on the field."
Comiskey suspects the widespread use of anti-inflammatories which enable athletes to take to the field when injured may be a factor in the increasing instances of sudden death.
Although sudden death is usually linked to pre-existing cardiac conditions, Comiskey believes conditions may be exacerbated by the use of these medicines.
Last September the anti-inflammatory pill Vioxx was withdrawn from the market after a study showed the drug doubled heart attack and stroke risk in patients who took it for at least 18 months.
Anti-inflammatories were implicated in a study on the premature deaths of soccer players from Lou Gehrig's disease by Italian anti-drug magistrate Raffaele Guariniello.
In a normal population of 24,000 - the number of soccer players in Italy's Serie A and Serie B from 1960-1997 - doctors might find one instance of the fatal neurological disease but the study pinpointed 40 cases.
Guariniello concluded the high incidence may simply be work-related. But he suspected the widespread use of anti-inflammatories, in particular corticosteroids, may have been a factor.
O'Brien believes the current situation with performance enhancing drugs is similar to that which surrounded smoking prior to the famous Hill and Doll study which linked smoking to cancer and heart disease.
"We had for many years Madison Avenue advertisers telling us smoking was safe when it was obvious people were dying."