CAMP FOSTER, Okinawa -- The parents of a soldier who died after taking a fitness supplement containing the ingredient DMAA will continue with a lawsuit against the manufacturer and retailer despite a recent Defense Department probe that found no significant link between the man's death and the stimulant.
Pvt. Michael Sparling's parents still believe DMAA contributed to their son's death at Fort Bliss, Texas, in 2011 and that the substance can kill or seriously injure some users even at recommended doses, according to their attorney Anne Andrews.
In a report published last month, a DOD safety review panel concluded that the once-popular fitness supplement -- also known as methylhexanamine -- posed an elevated health risk for tens of thousands of military users but that it did not appear the supplement was responsible for the deaths of Sparling, 22, or three other servicemembers who all collapsed while exercising.
The DOD says the findings are not conclusive, leaving unanswered questions over whether the stimulant could be deadly in rare cases.
"We are marching forward," Andrews said. "This is by no means a definitive study."
Sparling's parents filed suit in California in February against USPlabs, the maker of the DMAA supplement Jack3d, and retail giant General Nutrition Centers, claiming they had knowingly sold a dangerous product. An armed forces medical examiner ruled that Sparling died of accidental heat stroke. The examiner also found DMAA from the supplement Jack3d in his bloodstream.
Both USPlabs and GNC have repeatedly claimed that DMAA products are safe when used as recommended.
Joseph Fortunato, GNC's chairman, president and CEO, said the company was "delighted" that the DOD safety review found "products containing DMAA do not cause adverse medical events," according to a company press release this month.
However, the U.S. Food and Drug Administration last year ordered the supplements removed from the market and pressured the companies to destroy remaining stocks.
The DOD panel's report said the lack of any high levels of DMAA in the blood of the servicemembers who died suggest that DMAA did not play a significant role in the deaths. But Andrews said the reported blood levels only prove that Sparling died while taking the dosage recommended by the manufacturer. The stimulant still could have contributed to his death, she said.
The review panel also found servicemembers who took DMAA supplements for 80 days or longer were about three times more likely than other users to die or suffer heat injury, irregular heartbeat, seizures, muscle breakdown, brain hemorrhage or kidney failure. Andrews said that applies to Sparling's case because he had been taking the DMAA supplement Jack3d for longer than 80 days when he collapsed during his first physical training run with his new unit at Fort Bliss.
DOD spokeswoman Lt. Col. Cathy Wilkinson said the medical examiner opinions published in the report is its best assessment of the link between DMAA and the deaths based on a careful examination of the evidence.
But the findings should not be considered conclusive, according to Wilkinson.
"Many of the panel members remained personally concerned or persuaded that DMAA may have been a factor in the deaths with its stimulant properties, combined with other environmental and personal health factors," she wrote in an email. "We will not say that DMAA played no role. That question cannot be answered -- but the panel retained sufficient concern to recommend that sales of these products be permanently banned."
Pieter Cohen, an assistant professor of medicine at Harvard Medical School who has studied DMAA and stimulant use in the military, said the DOD review panel could not show DMAA caused the servicemember deaths but did not rule it out as a factor.
"And they do not address the question that we would want to know, ‘If the soldier had not taken DMAA, would they still have died?' " Cohen wrote in an email to Stars and Stripes.
He said the panel's findings are not surprising because it is much easier for researchers to show a substance like DMAA poses health risks to all consumers than prove it played a significant role in an individual death.
"The rare but real risk of DMAA is very similar to how adverse drug reactions work. Ephedra [a similar stimulant banned by the federal government] is the same way -- millions of consumers took ephedra without adverse effects, but some had strokes and some died," Cohen said.