North American (Panax quinquefolius) and Asian Ginseng (Panax ginseng) Preparations for Prevention of the Common Cold in Healthy Adults: A Systematic Review

Table 1

Characteristics of included studies.

Reference, country	Study design, duration, funding	Population (age, gender, setting)	Intervention (proprietary name, extract, dose)	Control (agent, dose)	Outcomes reported	Author's conclusions	Jadad score
McElhaney et al. [8], trial A, USA	RCT Parallel, 8 weeks, Manufacturer	82 years (mean), 20% male, Long-term care facility	𝑁=40, COLD-fX, North American ginseng, 2 × 200 mg day^−1	𝑁=49, Placebo, Microcrystalline cellulose, 2 × 200 mg day^−1	Clinically confirmed ARI, severity and duration of respiratory illness, laboratory-confirmed respiratory illness, severity and duration of influenza illness, AE.	COLD-fX was demonstrated to be potentially effective for the prevention of ARI, as well as safe and well tolerated	2/5
McElhaney et al. [8], trial B, USA	RCT Parallel, 12 weeks, Manufacturer	83.5 years (mean), 26% male, Long-term care facility	𝑁=57, COLD-fX, North American ginseng, 2 × 200 mg day^−1	𝑁=52, Placebo, Microcrystalline cellulose, 2 × 200 mg day^−1	Clinically confirmed ARI, severity and duration of respiratory illness, laboratory-confirmed respiratory illness, severity and duration of influenza illness, AE.	COLD-fX was demonstrated to be potentially effective for the prevention of ARI, as well as safe and well tolerated	2/5
McElhaney et al. [11], Canada	RCT Parallel, 16 weeks, Manufacturer	69 years (mean), 49% males, Community	𝑁=22, COLD-fX, North American ginseng, 2 × 200 mg day^−1	𝑁=21, Placebo, Microcrystalline cellulose, 2 × 200 mg day^−1	Incidence of ARI symptoms, duration of symptoms, AE.	COLD-fX reduced the relative risk and duration of respiratory symptoms, and is safe for daily use in immunocompetent seniors.	5/5
Predy et al. [10], Canada	RCT Parallel, 16 weeks, Manufacturer	43 years (mean), 40% males, Community	𝑁=130, COLD-fX, North American ginseng, 2 × 200 mg day^−1	𝑁=149, Placebo, Rice powder, 2 capsules day^−1	Incidence of colds reported and Jackson-verified, severity and duration of symptoms, AE.	Use of COLD-fX reduced the incidence of colds, proportion of subjects experiencing ≥2 colds, the severity and duration of colds.	5/5
Scaglione et al. [9], Italy	RCT Parallel, 12 weeks, Funding ND	48 years (mean), 58% males, Community, Multicenter	𝑁=114, Ginsana G115, Panax ginseng, 2 × 200 mg day^−1	𝑁=113, Placebo, ND, 2 capsules day^−1	Incidence of common colds and influenza, NK activity, specific antibody titres, AE.	Ginsana G115 helps improve human immune response and is able to protect against common cold and influenza.	2/5

AE: adverse events; ND: not described; NK: natural killer cells; RCT: randomized controlled trial.