Ginkgo biloba Does—and Does Not—Prevent Acute Mountain Sickness

• Published in: Wilderness & environmental medicine Vol. 20; no. 1; pp. 66 - 71
• Main Authors: Leadbetter, Guy, Keyes, Linda E, Maakestad, Kirsten M, Olson, Sheryl, Tissot van Patot, Martha C, Hackett, Peter H
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA Elsevier Inc 2009; SAGE Publications; Elsevier Limited
• Subjects: acute mountain sickness; Adolescent; Adult; altitude; Altitude Sickness - epidemiology; Altitude Sickness - pathology; Altitude Sickness - prevention & control; BRIEF REPORTS; Dose-Response Relationship, Drug; Double-Blind Method; Emergency; Female; ginkgo; Ginkgo biloba - chemistry; Humans; hypoxia; Male; Middle Aged; Mountaineering; Phytotherapy; Plant Extracts - analysis; Plant Extracts - pharmacology; Severity of Illness Index; Treatment Outcome; Young Adult; altitude; hypoxia; ginkgo; acute mountain sickness
• ISSN: 1080-6032; 1545-1534
• DOI: 10.1580/08-WEME-BR-247.1

Objective.—To determine the efficacy of 2 different sources of Ginkgo biloba extract (GBE) in reducing the incidence and severity of acute mountain sickness (AMS) following rapid ascent to high altitude. Methods.—Two randomized, double-blind, placebo-controlled cohort studies were conducted in which participants were treated with GBE (240 mg·d−1) or placebo prior to and including the day of ascent from 1600 m to 4300 m (ascent in 2 hours by car). Acute mountain sickness was diagnosed if the Environmental Symptom Questionnaire III acute mountain sickness–cerebral (AMS-C) score was ≥0.7 and the Lake Louise Symptom (LLS) score was ≥3 and the participant reported a headache. Symptom severity was also determined by these scores. Results.—Results were conflicting: Ginkgo biloba reduced the incidence and severity of AMS compared to placebo in the first but not the second study. In the first study, GBE reduced AMS incidence (7/21) vs placebo (13/19) (P = .027, number needed to treat = 3), and it also reduced severity (AMS-C = 0.77 ± 0.26 vs 1.59 ± 0.27, P = .029). In the second study, GBE did not reduce incidence or severity of AMS (GBE 4/15 vs placebo 10/22, P = .247; AMS-C = 0.48 ± 0.13 vs 0.58 ± 0.11, P = .272). The primary difference between the 2 studies was the source of GBE. Conclusions.—The source and composition of GBE products may determine the effectiveness of GBE for prophylaxis of AMS.