Echinacea might reduce chances of becoming ill, researcher says

According to a meta-analysis, Eginacea might reduce the chances of catching a cold by 58 percent, according to the latest in a long line of confusing and contradictory studies.

Better yet, echinacea might reduce the length of a cold by an average of 1.4 days -- a substantial savings, because colds cause 40 percent of the nation's lost work time, the authors of a recent study say.

The study, conducted by scientists from the University of Connecticut, is published online today in The Lancet Infectious Diseases, a British medical journal.

Over the years, studies of echinacea have shown "a trend of improving colds," but none involved enough patients to be statistically significant, said the author of today's article, Dr. Craig Coleman of the University of Connecticut's School of Pharmacy.

Other studies have shown just the opposite. In 2000, German scientists reported that echinacea could help treat colds but not necessarily prevent them. In 2005, a study of more than 400 patients published in the New England Journal of Medicine indicated that echinacea had no effect on colds at all.

Coleman's team performed a meta-analysis, combining the results of 14 independent studies involving more than 1,600 patients.

Some experts say that's still not good enough. They argue that Coleman's meta-analysis combines too many studies with different combinations of drugs.

"Some of the patients were also taking Vitamin C, rosemary, thyme ... you really don't know what's going on," said Dr. Adriane Fugh-Berman, associate professor of complementary and alternative medicine at Georgetown University.

To compensate for this problem, Coleman said, his team did a "sensitivity analysis" to determine whether echinacea worked on its own.

"There was still reduction in cold duration," Coleman said, but not enough to be statistically significant.

Steve - we treat meta-analysis of dietary supplements exactly as we do medications...very cautiously. This means that we are not going to blanketly start recommending echinacea just because of this review study. Echinacea has and always will be a mixed bag. It is low on the totem pole of our recommendations for immune boosters.

While some benefit from its positive effect on immune function, others do not. How one responds to echinacea, we believe, is due to one's genetic makeup. In addition, echinacea contraindicates with other herbs and some medications. We also never recommend taking it for more than two weeks at a time.