Ginseng for the Common Cold?
Drugs promising a cure for the common cold abound usually draw a healthy skepticism, but one drug - COLD-fXÂ®- is now surprisingly well backed up by a clinical trial.
In a peer-reviewed double-blind clinical study, COLD-fX (which contains an extract of North American ginseng) was tested for its ability to prevent upper respiratory tract infections. The study was published in the Canadian Medical Association Journal and reported by Time online's The Daily RX.
Clinical Trial Results
Researchers Predy et al. wrote, "Upper respiratory tract infections are a major source of morbidity throughout the world. Extracts of the root of North American ginseng (Panax quinquefolium) have been found to have the potential to modulate both natural and acquired immune responses.
"We sought to examine the efficacy of an extract of North American ginseng root in preventing colds."
The randomized, double-blind, placebo-controlled study included 323 adults, aged 18-65 years, and was conducted over four months during winter 2003-04 (the height of influenza season). Participants had a history of at least two colds in the previous year and were recruited from the general population in Edmonton, Alberta.
Participants took were instructed to take two capsules daily of either the North American ginseng extract or placebo over a four-month period. The primary outcome-measure was the number of Jackson-verified colds, and secondary outcome-measures included symptom severity, duration of symptoms, and duration of colds. Participants scored their cold symptoms using a 4-point scale.
Results showed that participants who took COLD-fX had 25% fewer upper-respiratory infections, compared with those taking placebo. Moreover, those who developed infections reported lower symptom severity, on average.
The study appears to confirm previous smaller-scale studies showing treatment with COLD-fXÂ® reduces cold- or flu-virus levels in patients' systems.
A cure for the common cold? Michael Lemonick, The Daily Rx, Time online, 24 October 2005.
Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infections: a randomized controlled trial. Gerald N. Predy et al., Canadian Medical Association Journal, volume 173 (9), 25 October 2005.
Posted: November 2005