RT Journal Article SR Electronic T1 Complementary and alternative medicine for prevention and treatment of the common cold JF Canadian Family Physician JO Can Fam Physician FD The College of Family Physicians of Canada SP 31 OP 36 VO 57 IS 1 A1 Richard Nahas A1 Agneta Balla YR 2011 UL http://www.cfp.ca/content/57/1/31.abstract AB Objective To review the evidence supporting complementary and alternative medicine approaches to treatment and prevention of the common cold in adults. Quality of Evidence MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched from January 1966 to September 2009 combining the key words common cold or influenza with echinacea, garlic, ginseng, probiotics, vitamin C, and zinc. Clinical trials and prospective studies were included. Main Message For prevention, vitamin C demonstrated benefit in a large meta-analysis, with possibly increased benefit in patients subjected to cold stress. There is inconsistent evidence for Asian ginseng (Panax ginseng) and North American ginseng (Panax quinquefolius). Allicin was highly effective in 1 small trial. For treatment, Echinacea purpurea is the most consistently useful variety; it was effective in 5 of 6 trials. Zinc lozenges were effective in 5 of 9 trials, likely owing to dose and formulation issues. Overall, the evidence suggests no benefit from probiotics for prevention or treatment of the common cold. Conclusion Vitamin C can be recommended to Canadian patients for prevention of the common cold. There is moderate evidence supporting the use of Echinacea purpurea and zinc lozenges for treatment. Ginseng and allicin warrant further research.