reviewed by X. Li, Ph. D.
(credential)
When people climb high mountains or ski at high altitudes, they commonly experience a shortage of
oxygen due to reduced oxygen concentrations in the air. Some people may further experience
headache, poor appetite, nausea, fatigue, dizzy, poor sleep. In severe cases, they may have to
lay down on bed. These and other similar physiological reactions are collectively called acute
mountain sickness (AMS). AMS disappears after returning to lower altitudes.
As ginkgo biloba has been shown to improve circulation to the brain and to the extremities of the body
and to protect cells from damages due to the under-supply of oxygen or blood, some researchers
wonder if ginkgo would help preventing acute mountain sickness.
A group of French scientists conducted a trial to study if ginkgo can prevent the occurrence
of acute mountain sickness in 44 people who were on a Himalayan expedition1. All the participants
had experienced acute mountain sickness previously. They were randomly divided to two
groups. One group started to receive 160 mg standardized ginkgo biloba extract per day in two
divided doses 5 days before the climbing. The other group received placebo. The climbers
ascended from 1800 m to 5200 m over 10 or more days. The result is quite astonishing.
3 climbers (14%) in the ginkgo group developed one or more mild symptoms of acute mountain sickness,
compared to 18 climbers (82%) in the placebo group. In addition, none in the ginkgo group
experienced full symptoms of acute mountain sickness. However, in
the placebo group, 41% of climbers had developed full symptoms of acute mountain sickness.
This trial result suggests that taking ginkgo 5 days before climbing can effectively prevent
the occurrence of acute mountain sickness.
A second study in USA tried to confirm the finding of the French study2. This time the researcher
chose Mauna Kea of Hawaii where road transportation is available to ascend people from sea level to
4205 m in just 3 hours. 26 people were involved in the study who had no recent hospitalization,
no chronic illness, did not ascended to over 2000 m, and did not take ginkgo. They were randomly divided to two
groups. One group took 60 mg standardized ginkgo biloba extract three times per day
just 1 day before the ascending and on the ascending day. The other group received placebo.
Neither participants nor researchers knew who is taking ginkgo or placebo before the end of
study to ensure the objectiveness of evaluation. As the result, 2 out of 14 participants in the ginkgo group
(17%) developed acute mountain sickness, whereas 9 out of 14 participants in the placebo group
(64%) developed acute mountain sickness. The difference is statistically significant and suggestive again
of the effectiveness of ginkgo in prevention of acute mountain sickness just one day before the
ascent.
In summary, although the trial sizes are relatively small both trials provided positive results supporting the
effectiveness of ginkgo in preventing acute mountain sickness in mountain climbers. Taking
ginkgo just one day before ascending may be good enough for the prevention. While future larger studies
are needed to further confirm the results of these two studies, the good
safety profile and inexpensiveness of ginkgo make it a good recommendation for climbers or skiers
to prevent adverse physiological reactions to high altitudes.
Reference
1. Roncin JP, Schwartz F, D'Arbigny P. EGb 761 in control of acute mountain sickness and vascular reactivity to cold
exposure. Aviat Space Environ Med. 1996 May;67(5):445-52.
2. Gertsch JH, Seto TB, Mor J, Onopa J. Ginkgo biloba for the prevention of severe acute mountain sickness (AMS)
starting one day before rapid ascent. High Alt Med Biol. 2002
Spring;3(1):29-37.
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