A study of data from poison control centers shows the controversial supplement ephedra is by far the most dangerous herbal product on the market, San Francisco researchers claim.
While ephedra accounted for less that 1 percent of herbal supplement sales in 2001, it was responsible for 62 percent of all the herbal-related reports made to poison control centers that year, says a study that will appear in the March 18 issue of the Annals of Internal Medicine.
The study was immediately called worthless by Wes Siegner, legal counsel for the Ephedra Education Council, an industry group.
“If you start with garbage and analyze garbage, you end up with garbage,” Siegner says.
Ephedra, also known as ma-huang, has been used for hundreds of years and now is promoted as an aid to weight loss and an energy booster, among other things. Side effects attributed to it include anxiety, insomnia, increased blood pressure and increased heart rate, and its use has been associated with an increased risk of heart attack and stroke. The U.S. Army bans it from commissaries and post exchanges, and the National Football League forbids players from using it.
The Bush administration has commissioned a RAND Corp. study to determine whether ephedra should be regulated by the U.S. Food and Drug Administration(FDA), a move denounced as a delaying tactic by consumer groups that have demanded an ephedra ban. The RAND report is expected in March or April.
“We hope that our paper will add information to inform this decision,” says study author Dr. Michael Shlipak, a staff physician at the San Francisco Veterans Affairs Medical Center who is also an assistant professor of epidemiology and biostatistics at the University of California, San Francisco (UCSF).
Shlipak did the study with Dr. Stephen Bent, another UCSF physician who is interested in herbal medicine and alternative medicine. Together, they went through the data published by the American Association of Poison Control Centers, most of whose information originates from calls from the general public.
Their paper lists 1,178 adverse reactions attributed to ephedra, compared to 664 for all other herbal products. The most recorded for any other product was 69, for echinachea. The researchers calculate that ephedra poses a risk 200 times greater than all other herbal supplements combined, with individual relative risks of 100 times greater than kava and 720 times greater than ginkgo biloba.
“We were very struck by our results,” Shlipak says.
Until now, almost all of the evidence implicating ephedra as a health risk has come from individual case reports, which made it difficult to determine the magnitude of the risk, he says. “This was not an unprecedented method, but we thought it creative,” he says.
However, Siegner’s word for the method is “worthless.”
“It is universally agreed that you can’t base risk on adverse event reports,” he says. “You can’t compare adverse event reports of one product to another product and assess risk.” For example, people are more likely to report adverse events concerning a highly publicized product such as ephedra, Siegner explains.
In Siegner’s view, the report is further compromised by the fact that one of its authors, Thomas N. Tiedt, has been “actively working with plaintiffs who are suing” about ephedra. Tiedt, a consultant, freely admits testifying in various lawsuits against the substance, but adds that the Ephedra Council just “throws a brick” with that accusation because its experts have testified for the other side in those same lawsuits.
“You have to do more clinical work to estimate whether there is a risk,” Siegner says. “That will be the definitive review.”