Ginkgo biloba for the Prevention of Severe Acute Mountain Sickness (AMS) Starting One Day before Rapid Ascent

Abstract

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. This is the first study to demonstrate that 1 day of pretreatment with ginkgo 60 mg TID may significantly reduce the severity of AMS prior to rapid ascent from sea level to 4205 m.

Ginkgo Biloba Extract Prevents High Altitude Pulmonary Edema in Rats

“…Although controversial, ginkgo has been shown to benefit patients suffering from cardiovascular disease (Mahady, 2002) and peripheral arterial disease (Pittler and Ernst, 2000). In addition, ginkgo reduces the severity of acute mountain sickness (Roncin et al, 1996;Leadbetter et al, 2001;Gertsch et al, 2002) when administered before high altitude exposure, but, interestingly, looses protective ability when given to subjects residing at altitude (14,000 ft) (Gertsch et al, 2004). This suggests that ginkgo exerts its protective effect early in the course of HAPE.…”

“…I NVESTIGATIONS HAVE SHOWN that Ginkgo biloba reduces the severity of acute mountain sickness in humans (Roncin et al, 1996;Leadbetter et al, 2001;Gertsch et al, 2002). The mechanism(s) of protection have not been identified, but may be associated with ginkgo's ability to quench free radicals (Louajri et al, 2001) or inhibit hypoxia-induced decreases in ATP generation (Janssens et al, 1995).…”

Amelioration of rCBF and PbtO2 following TBI at high altitude by hyperbaric oxygen pre-conditioning

“…Ambient PO 2 and arterial PO 2 is about 97 and 56 mmHg, respectively. The incidence rate of acute mountain sickness in the general tourist population is reported at 40-50% among trekkers and climbers near 4000 m 18 and increases to more than 90% when an ascent to about 4000 m occurs over a number of hours rather than days 19 . Because rodents are somewhat less susceptible to high altitude hypoxia than humans at the same altitude, the altitude of 4000 m was chosen as a simulated high altitude for rats in this study to avoid the effects of high altitude illness on TBI.…”

Prevention and treatment of high-altitude illness in travelers

“…Gingko 120 mg twice daily taken for 5 days before exposure reduced the incidence and severity of AMS during ascent from 1400 to 4300 m over 2 hours [38]. In a third study, gingko 60 mg three times daily starting 1 day before rapid ascent from sea level to 4205 m reduced the severity (but not incidence) of AMS compared to placebo [39]. Gingko's effects may be because of its antioxidant activity.…”