Ginkgo biloba has a remarkable ability to increase blood flow throughout the body, enabling it to cope better with decreased atmospheric oxygen levels. The leaf extracts have antioxidant properties which increase vasodilation and peripheral blood flow in the capillary vessels. It also decreases blood viscosity and helps regulate cerebral energy metabolism.
The first study cited below is the most compelling data to date supporting the efficacy of Ginkgo biloba in prevention of altitude mountain sickness. A group taking Ginkgo biloba had no increase in their AMS score (which is remarkable), while acetazolamide and placebo groups showed increases of 36% and 54%, respectively. The authors concluded that their study provided evidence supporting the use of Gingko biloba in the prevention of AMS, demonstrating that 24 hours of pre-treatment with Gingko biloba and subsequent maintenance during exposure to high altitude are sufficient to reduce the incidence of AMS in participants with no previous high-altitude experience.
Wilderness Environ Med. 2007 Winter;18(4):251-7.
Ginkgo biloba decreases acute mountain sickness in people ascending to high altitude at Ollagüe (3696 m) in northern Chile.
Moraga FA, Flores A, Serra J, Esnaola C, Barriento C.
Laboratorio de Fisiología, Escuela de Medicina, Universidad Católica del Norte, Coquimbo-Chile.firstname.lastname@example.org
OBJECTIVE: To determine the prophylactic effect of Ginkgo biloba (doses 80 mg/12 h, 24 h before high-altitude ascension and with continued treatment) in preventing acute mountain sickness (AMS) at 3696 m in participants without high-altitude experience.
METHODS: Thirty-six participants who reside at sea level were transported to an altitude of 3696 m (Ollagüe). The participants were divided into 3 groups and received G biloba (n=12) 80 mg/12 h, acetazolamide (n=12) 250 mg/12 h, or placebo (n=12) 24 hours before ascending and during their 3-day stay at high altitude. The Lake Louise Questionnaire constituted the primary outcome measurement at sea level and at 3696 m. A Lake Louise Self-Report Score greater than 3 was indicative of AMS. Oxygen saturation, heart rate, and arterial pressure were taken with each evaluation for AMS.
RESULTS: A significant reduction in AMS was observed in the group that received G biloba (0%, P<.05) comparison with the groups receiving acetazolamide (36%, P<.05) or placebo (54%). No difference was observed in arterial oxygen saturation in the G biloba (92+/-2) vs the acetazolamide (89+/-2) groups. However, a marked increased saturation in arterial oxygen was seen in comparison with the placebo group (84+/-3, P<.05). No statistically significant differences were observed in mean arterial pressure or heart rate.
CONCLUSIONS: This study provides evidence supporting the use of G biloba in the prevention of AMS, demonstrating that 24 hours of pretreatment with G biloba and subsequent maintenance during exposure to high altitude are sufficient to reduce the incidence of AMS in participants with no previous high-altitude experience.
High Alt Med Biol. 2002 Spring;3(1):29-37.
Ginkgo biloba for the prevention of severe acute mountain sickness (AMS) starting one day before rapid ascent. Gertsch JH, Seto TB, Mor J, Onopa J. The University of Hawaii, John A. Burns School of Medicine, and the Kapiolani Clinical Research Center, Honolulu, Hawaii 96813, USA.
Previous studies suggest that 5 days of prophylactic ginkgo decreases the incidence of acute mountain sickness (AMS) during gradual ascent. This trial was designed to determine if ginkgo is an effective prophylactic agent if begun 1 day prior to rapid ascent. In this double-blind, randomized, placebo-controlled trial, 26 participants residing at sea level received ginkgo (60 mg TID) or placebo starting 24 h before ascending Mauna Kea, Hawaii. Subjects were transported from sea level to the summit (4205 m) over 3 hours, including 1 hour at 2835 m. The Lake Louise Self-report Questionnaire constituted the primary outcome measure at baseline, 2835 m, and after 4 h at 4205 m. AMS was defined as a Lake Louise Self-report Score (LLSR) >/= 3 with headache. Subjects who developed severe AMS were promptly transported to lower altitude for the remainder of the study. The ginkgo (n = 12) and placebo (n = 14) groups were well matched (58% vs. 50% female; median age 28 yr, range 22-53 vs. 33 yr, range 21-53; 58% vs. 57% Caucasian). Two (17%) subjects on ginkgo and nine (64%) on placebo developed severe AMS and required descent for their safety (p = 0.021); all recovered without sequelae. Median LLSR at 4205 m was significantly lower for ginkgo versus placebo (4, range 1-8 vs. 5, range 2-9, p = 0.03). Ginkgo use did not reach statistical significance for lowering incidence of AMS compared with placebo (ginkgo 7/12, 58.3% vs. placebo 13/14, 92.9%, p = 0.07). Twenty-one of 26 (81%) subjects developed AMS overall.