|Date: December 15, 2005||HC# 110452-294|
Re: Trial Finds American Ginseng Extract Effective in Treatment of Colds
Songisepp E, Kals J, Kullisaar T, et al. Evaluation of the functional efficacy of an antioxidative probiotic in healthy volunteers. Nutrition J. 2005; August:1-10.
On average, Americans get 2-6 colds each year. Finding ways to reduce the frequency of the common cold is important. Botanicals that stimulate the immune system have been used to combat the common cold, but clinical studies have been inconclusive. North American ginseng (Panax quinquefolius) has immunomodulatory effects. A patented poly-furanosyl-pyranosyl-saccharides- rich extract of North American ginseng (COLD- FX, CV Technologies Inc, Edmonton, Alberta, Canada) has been shown in vitro to stimulate the immune system. An increase in immune activity may decrease susceptibility to colds. The purpose of this study was to test this extract as a prophylactic treatment for upper respiratory tract infections.
Healthy subjects (n = 323) who had at least 2 colds in the past year participated in this randomized, double-blind, placebo-controlled study conducted at the University of Alberta, Edmonton, Canada. Subjects took either placebo or 400 mg per day of a standardized extract formulated from the roots of North American ginseng (80% poly-furanosyl-pyranosyl-saccharides and 10% protein) for 4 months. Treatment began just after the onset of influenza season. Subjects were instructed not to take any other cold medication unless advised by their physician. Every evening the subjects completed a diary detailing the severity of cold-related symptoms. A 2-day total symptom score greater than 14 was considered to indicate a Jackson-criteria verified cold. The Jackson score is one of the most restrictive definitions of a cold because it quantifies cold symptoms. By contrast, other studies use the absence or presence of a runny nose to define a cold.
There were no significant differences in baseline characteristics between the groups. Compliance was rated high in both groups and blinding was maintained (77% of the patients taking placebo thought they were taking ginseng). There was a 13% reduction in the absolute risk of getting recurrent colds meeting the Jackson criteria. The mean number of Jackson-verified colds per person was significantly less in the ginseng group than in the placebo group (P < 0.017). Fewer subjects in the ginseng group than in the placebo group reported contracting at least 1 cold during the study, but the difference was not statistically significant. However, there was a significant difference in the recurrence of colds, with 10% in the ginseng group having more than one cold compared with 23% in the placebo group (P = 0.004). Ginseng treated subjects had less severe symptoms (P = 0.002) and were sick for fewer days (P < 0.001). The interventions were well tolerated. There was no significant difference between the groups in the use of NSAIDs or antibiotics.
The authors concluded that the ginseng extract is a safe and effective treatment for reducing the absolute risk of recurrent colds and the mean number of colds per person. They do point out that the findings only apply to healthy adults and studies in children and immunocompromised adults are needed. This study had excellent methodology and reporting, which provides additional credibility to the findings. Unfortunately, a 13% reduction in the risk of getting a cold does not seem particularly clinically valuable. However, more promisingly, "the total symptom score was 31.0% lower and the total number of days symptoms were reported 34.5% less in the ginseng group than in the placebo group over the 4-month intervention period."
Also, the activity of this N. American ginseng extract seems to compare favorably with that of common antiviral drugs such as rimantadine, amantadine, zanamivir and oseltamivir (Tamiflu®). The N. American ginseng extract was reported in an earlier study with elderly people, to reduce the relative risk of laboratory-confirmed influenza infections by 89%, an effectiveness similar to that of zanamivir and oselltamivir2; these antiviral agents have been reported to reduce the severity and duration of illness by 1.5-2.5 days3, while this ginseng treatment reduced the duration of a cold by 2.4 days.
The authors of this study further assert that "This North American ginseng extract has a broader ranger of activity (than common antivirals) and hence is potentially more effective in combating different strains of virus."
—Heather S. Oliff, PhD
1.McElhaney JE, Gravenstein S, Cole S, Davidson E, O’Neill D, Petigean S et al. A placebo-controlled trial of a proprietary extract of North Amercan ginseng (CVT – E 002) to prevent acute respiratory illness in institutionalized older adults. J Am Geriatr Soc 2004; 52:13-19.
2.Turner D, Wailoo A, Nicholson K, Cooper N, Sutton A, Abrams K. Systematic review and economic decision modeling for the prevention and treatment of influenza A and B. Health Technol Assess 2003; 7:1-170.
3.Stiver G. The treatment of influenza with antiviral drugs. Can Med assoc J 2003; 168(1): 49-57.