Runner Who Died During Marathon Took DMAA During Race

February 04, 2013

LONDON — The death of Claire Squires, a 30-year-old hairdresser who died one mile from the finish line of the 2012 London Marathon, was likely caused by consuming Jack3d (USPlabs), a performance-enhancing supplement that contained the amphetaminelike stimulant 1,3-dimethylamylamine (DMAA).

Jack3d was banned by the Medicines and Healthcare Products Regulatory Agency (MHRA) four months after Squires's death. DMAA has been linked to psychiatric disorders, MI, and stroke and is banned by the World Anti-Doping Agency (WADA), as well as banned in Australia, Canada, and the US. In 2012, two US soldiers taking the supplement died of cardiac arrest while performing military exercises. Despite these bans, it is still widely available online.

According to a report in the Guardian, Squires purchased Jack3d online. Her boyfriend, Simon Van Herreweg, told the newspaper that Squires took the supplement "a couple of times" before the marathon but "didn't really get on with it." She was hoping to break her previous marathon best of four hours and planned to take one scoop of the mixture in a drink to see if it could push her through to the end of the marathon.

Complicating the picture slightly is that Squires also had an irregular heartbeat, which might have made her particularly vulnerable to the supplement. However, the coroner does not believe that the arrhythmia played a role in her death. Dr Jon van der Walt, the physician who conducted the postmortem, said the "balance of probability" suggested that the cause of death is cardiac failure caused by extreme physical exertion complicated by DMAA. Squires, according to van der Walt, had been active for many years, something he regarded as a stress test. "She had been able to do all this before; therefore, it is unlikely that she had fatal arrhythmia."

Speaking with heartwire , Dr Aaron Baggish (Massachusetts General Hospital, Boston) said the situation is somewhat tricky because the presence of DMAA in Squires's system doesn't establish that this was the cause of her death but added that the product can fairly be described as a health risk. He said that DMAA is also banned by the US Anti-Doping Agency and the International Olympic Committee (IOC) because it is considered performance enhancing. Taken during intense exercise, DMAA not only would increase heart rate but also contractility, which has the overall effect of increasing the heart's workload.

"If somebody was teetering on the edge of having a rhythm problem, and I know there was some concern about the young lady having an irregular heartbeat, for what that's worth, this could be the final straw," said Baggish.

As the cardiologist for the Boston Athletic Association, the organizers of the prestigious Boston Marathon, Baggish said the medical directors are preparing to send out a mass email to registered runners training for the April race encouraging them to become aware of these banned substances and to avoid any stimulants, such as DMAA. "Without any clear evidence that this is what killed this woman, it still makes sense for people to stay away from it and other similar products."