Your secret weapon against Acute Mountain Sickness?

Ginkgo Biloba may be the oldest seed plant in the world, midway between a fern and a conifer. It traces its ancestry almost unchanged via Ginkgo Adiantoides, which flourished in the Tertiary Period (56 million years ago) all the way back to the Permian period, 270 million years ago.

Now recent trials among mountaineers have indicated that extract of Ginkgo Biloba seems to help alleviate symptoms of altitude sickness. I tried it on a recent climbing trip to Bolivia. And yes, I think it did help. I will be using it again next time I go climbing.

Buy your supplies of Ginkgo Biloba here

Note: I have no interest in any herbalist or seller of Ginkgo Biloba. In fact, I'm a well-known sceptic when it comes to alternative "medicine".

Note: Ginkgo is also spelled Ginko, and even Gingo. I wouldn't care, but if I didn't mention it, mis-spellers might not find this page when they search the web.

Background - Altitude, Acute Mountain Sickness, HACE and HAPE

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Pequeno Alpamayo, Bolivia. Altitude - 5369m (17,618 ft). 5 August 2003. Ginkgo Biloba refreshes the parts other herbs cannot reach. Photo Michael Liebreich.

There is much confusion about the effects of altitude on health. If you don't know about altitude sickness (Acute Mountain Sickness, HACE and HAPE) and you are going mountaineering, please see the links below and spend some time informing yourself. Your life or that of your buddies could depend on it!

Ginkgo Biloba will not help prevent HACE or HAPE, but it does seem to help against Acute Mountain Sickness (AMS). Anyone venturing to altitudes above 2000m (6560ft) runs the risk of this debilitating condition. If your trip takes you above an altitude of 4000m (13100ft) it is almost inevitable you will suffer from one or more of its symptoms at some point.

AMS is a spectrum disorder: it runs seamlessly from feeling a bit off-colour to being really very ill. In order to monitor it in yourself, you can use following AMS scorecard:

AMS Scorecard
Symptom Score Headache 1 Nausea or loss of appetite 1 Sleeping problems (insomnia) 1 Giddiness/Dizziness 1 Headache that remains after aspirin 2 Vomiting 2 Difficult breathing at rest 3 Abnormal or intense fatigue 3 Decreased urination 3	Total Score AMS Degree Treatment 1-3 Light Aspirin or paracetamol 4-6 Moderate Aspirin or paracetamol; rest, prevent ascent > 6 Acute Descend, Descend, Descend!
Note: this scorecard only covers AMS - it does not predict the onset of HACE or HAPE (see below)!

There are two other conditions about which you need to know if you are venturing into high mountains: High Altitude Pulmonary Edema (HAPE) and High Altitude Cerebral Edema (HACE). These are very serious, immediately life-threatening diseases which require immediate medical attention. See links for more information.

PLEASE NOTE - No one is claiming that Ginkgo Biloba has any protective effect against the onset of HACE or HAPE. Its potential effects are restricted to AMS. If you don't know about HACE and HAPE, find out before you ascend to altitude!

Although AMS is a potentially life-threatening condition, its worst effects can be mitigated by undertaking a proper acclimatisation programme. If you are travelling with a qualified guide and/or a reputable trekking company, then they should have designed your itinerary with this as a primary concern. The key is to ascend to altitude in stages, probing higher altitudes during the day but retreating at least a few hundred metres to sleep, and building in rest days at lower altitudes for the body to recover.

Sadly, in many high mountain ranges unscrupulous locals try to ensnare unsuspecting backpackers into expeditions to high local peaks. Often they only charge $100 or so, offering tents, clothing, ropes, guides etc all in. The problem is, they either don't know, or don't care about altitude sickness. Nor do they care whether or not you summit: they get paid either way; if you feel ill at altitude, you'll probably recover on the way down; if you abandon, they get home early. So even if you have been trekking at 4000m for a month, don't try a 6000m mountain unless you have a plan for acclimatisation.

So that's a brief introduction to altitude sickness. It's the bane of high altitude mountaineers, everyone suffers from one or more of its symptoms at some point. So if Ginkgo Biloba has a positive effect, it will be a welcome weapon in the climber's armoury.

Ginkgo and medicine - a short history

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The distinctive leaves of Ginkgo Biloba, used as a medicine in China for thousands of years. Munch and climb!

The venerable Ginkgo Biloba has long been thought to have medicinal powers; indeed it was cultivated as long ago as 1100 AD by Buddhist monks in China, whose actions may have saved it from extinction.

Perhaps inevitably for a plant with such a politically correct heritage, Ginkgo Biloba is now revered by afficionados of alternative medicine. They believe it is a cognitive enhancer - they swear it improves memory and speed of thinking, and can cure Alzheimer's Disease.

Personally, I tend not to trust pharmaceutical claims made by people with dreadlocks, at least until they have been verified by people without. What has been proven is that Ginkgo can increase blood flow to the extremities - enough so that its potential medical benefits have begun undergoing serious and rigorous testing.

In 1996 a French team investigated the use of Ginkgo at altitude. If it could increase blood-flow, they reasoned, it might help keep climbers warm. The found that not only did it help with altitude sickness, but also that it kept climbers warm.

Then in 2000, an American team conducted a proper, though small, double-blind trial of Ginkgo on 40 student volunteers. Half of them were fed the drug (120mg twice a day), the other half a placebo. Neither the subjects nor the testers knew until afterwards who was on the drug and who not. The results were statistically significant: the team concluded that Ginkgo Biloba does indeed help.

In 2002, a team in Hawaii investigated the use of Ginkgo Biloba one day before a rapid ascent from sea-level to over 4000 metres. They concluded that Ginkgo was useful in avoiding the onset of acute AMS in those circumstances, but few climbers are going to ascend to that altitude so rapidly (unless, that is, you are flying in to La Paz!).

The centre of gravity of Ginkgo and Altitude Sickness research has recently shifted to the Pheriche Medical Centre, where Everest Base Camp treckers can be experimented on in large numbers. But in August 2003, the Wilderness Medical Society concluded that none of the studies to date included sufficient numbers or gave Ginko for a sufficient duration before ascent to prove conclusively that it has a benefit.

It is hoped that studies to be undertaken in Pheriche in spring 2004 will establish once and for all whether Ginkgo is effective against symptoms of AMS, whether it is better than Acetazolamide (Diamox) and if so what is the optimum doseage/frequency/duration.

Interestingly doctors are now looking at using Sildafenil, otherwise known as Viagra, in the treatment and prevention of HAPE. Try explaining that to the Nepalese helicopter pilot as you get evacuated from Everest Base Camp!

My own Ginkgo/AMS experience

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In the past, I have suffered very badly from AMS while acclimatising. I felt there was enough scientific information to indicate that Ginkgo Biloba might help, so I decided to give it a go on my recent climbing trip to Bolivia.

I decided to go for the same doseage as the Pike's Peak trial: 120mg twice a day. There has not yet been enough research into optimum doseages, so that seemed as good a guess as any. I started one week before departure, and kept going without missing a capsule until the morning of my last climb.

The capsules seem to be full of a kind of beige powder, and they taste like something you might find behind the radiator in a store-room at the Natural History Museum. They wash down pretty easily with a couple of sips of water, and are less unpleasant to take for an extended period than most malaria tablets.

Over the week before departure I monitored my cognitive abilities carefully. Sadly, there seemed to be no change, I was unable to beat the high-score at Snake on my mobile phone. Damn - one myth exploded.

Over three weeks in Bolivia, however, I concluded that the Ginkgo almost certainly helped me:

My AMS experience by trip and medication status over the years
Trip	Max height reached	Year	Medication	AMS outcome
Kinabalu	4093m	1996	None	Splitting headache, insomnia
Kilimanjaro	5895m	1998	None	Splitting headache, nausea, vomitting spaghetti on summit day morning
Elbrus	5642m	1999	None	Splitting headaches throughout
Ecuador	6050m	2001	None	One splitting headache, severely disrupted sleep over 4500m
Bolivia	6200m	2003	Ginkgo Biloba	Occasional mild morning headaches, mild sleep apnea over 5000m

Conclusion: I certainly suffered less from AMS in Bolivia, taking Ginkgo, than I have done on previous high altitude mountaineering trips. I can only say it 'almost certainly helped', of course, because it is impossible to conclude from one person's experience whether or not a drug is helping - the only way is through a proper double-blind trial.

The Pike's Peak Study, 2000

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Despite all the interest in Ginkgo and AMS, the single best source of proper (i.e. scientific) information remains the Pike's Peak study. So here is what it said:

Summary: Double-blind, placebo-controlled study study; 40 college students who lived at 1400m (4,597 ft) were taken rapidly to 4300m (14,110 ft) on Pike's Peak, two hours by vehicle, and spent the night. Compared to those taking placebo, subjects taking ginko had half the incidence of AMS symptoms, and those on ginkgo who did become ill had far milder symptoms. Protocol: Ginkgo Biloba 120 mg orally twice a day, starting 5 days prior to the ascent, and continuing at altitude. Results: AMS defined as ESQ-III score > 0.7 and Lake Louise Score > 3 Subjects with AMS: 7 of 21 on ginkgo vs. 13 of 19 on placebo Mean Lake Louise Scores 3.9±0.6 on ginkgo vs. 6.2±0.9 on placebo; mean ESQ-III scores 0.77±0.20 on ginkgo vs. 1.59±0.32 on placebo Conclusion: Ginkgo Biloba taken five days prior to rapid ascent to 4300 m reduced both incidence and severity of AMS. References: Maakestad K, Leadbetter G, Olson S, Hackett P. Ginko biloba reduces incidence and severity of acute mountain sickness.(Abstract) Proceedings Wilderness Medical Society Summer Conference, Park City, Utah. August 9-12, 2000. Speculation (by Dr Peter Hacket, MD, President of the International Society of Mountain Medecine): Ginkgo biloba inhibits inducible nitric-oxide synthase (iNOS) and also scavenges oxygen radicals; one of these actions might explain its effectiveness in preventing AMS.

Evidence II - The Hawaii Study, 2002

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

Previous studies suggest that 5 days of prophylactic ginkgo decreases the incidence of acute mountain sickness (AMS) during gradual ascent (see above, the Pike's Peak Study.

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.

Evidence III - Himalayan study, 1996

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Roncin J, Schwartz F, D'Arbigny P: Acute Mountain Sickness (AMS)/Vascular Reactivity to Cold. Aviation, Space, and Environmental Medicine 67, 445-452, 1996.

• 44 healthy subjects who had previously experienced AMS (minimum score of 2 on AMS questionnaire)
• Randomized parallel study of preventive effect of GBE on AMS and vasomotor changes of the extremities during a 30-day Himalayan trip (altitude at the base camp was 4900 meters)
• One group (22) received GBE (2x80 mg/day) while the other group (22) received a placebo
• Principle assessment criterion was score on Environmental Symptoms Questionnaire (ESQ) comprising 67 items each scored on a 6-point scale
• Symptoms on the ESQ include:
  • aching in legs, feet, shoulders, arms, hands
  • coldness in hands/feet
  • numbness in a body part
  • "feeling sick"
  • decreased diuresis
  • headache, insomnia, vertigo, nausea (cerebral AMS)
  • dyspnea on exertion/at rest (respiratory AMS)
• Questionnaires were filled out daily during ascent to base camp (8 days) and for 3 days following; then on days 17, 20, 21, 23
• Results from principle assessment (ESQ):
  • Zero (GBE); 41% (placebo) developed cerebral AMS
  • 14% (GBE); 82% (placebo) developed respiratory AMS
• Secondary assessment criteria were based on:
  • functional disability (six point scale assessing parasthesia, pain, numbness, stiffness, swelling of hands)
  peripheral vasomotor reactions measured by plethysmography (days 0,15-17, 28-30)
  • digital systolic pressure (DSP) at room temperature
  • DSP after 3 minutes at 10 degrees C
  • Difference between 1 and 2 is the cold gradient
• Results from plethysmography measurements:
  • 23% improvement (decrease) in cold gradient (GBE)
  • 104% deterioration (increase) in cold gradient (placebo)

Conclusion: GBE appears to be a useful treatment for the prevention of AMS. It is well tolerated with no particular adverse effects. Its efficacy vs. placebo has been demonstrated on both cerebral and respiratory components of AMS. It also decreases vasomotor disorders of the extremities, as demonstrated by plethysmography and a specific functional disability questionnaire.

What doseage to take

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If you decide to take Ginkgo Biloba on your next high altitude trip, go for 120mg capsules twice a day.

The doseages used in the studies were 80mg twice a day in the 1996 French study), and 120mg twice a day in the 2000 Pike's Peak study. I took 120mg twice a day. More research is needed into optimum doseages.

Buy from a reputable firm, and make sure you go for standardised capsules: they should contain 24% flavonoids, 6% terpenoids (including 0,8% min. ginkgolide B), and a 50:1 ratio (fifty pounds of ginkgo leaves for one pound of ginkgo extract). Many of the less expensive ginkgo products use an 8:1 ratio, which results in a flavonoid content of only 4% to 6% and a lower terpenoid content.

Side effects and contraindications

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In general, Ginkgo Biloba appears to be very safe, having been consumed in large quantities for medicinal purposes in China over centuries with no noticable ill-effects.

In the west, among the general population of Ginkgo-munchers there have been a few cases of haemorrhages, haematomas and one coma (in an 80-year-old patient). None of these has been definitively associated with the patient's use of Ginkgo, and patients in control groups had a similar incidence of side-effects.

Since Ginkgo has demonstrated anti-platelet activity, it should not be taken by anyone on anti-coagulants such as acetylsalicylic acid, rofecoxib, warfarin and trazodone. There are cases of people on Warfarin haemorrhaging when also taking Ginkgo supplements.

If you do decide to take Ginkgo on your next climbing trip, then it may make sense to avoid using Aspirin as your analgesic of choice, since it is also a blood thinner. Stick to paracetamol for the inevitable AMS headaches.

Diamox and other alternatives to Ginkgo Biloba

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Of course there are alternatives to taking Ginkgo Biloba on your next mountaineering expedition.

• Diamox (Acetazolamide). This is big pharma's entry in the AMS management stakes. On the plus side, it has been rigorously proven to work, though not for everyone. The generally-accepted doseage is 125mg every 12 hours, starting one week before ascent, doubling this to 250mg ever 12 hours if AMS symptoms surface. On the minus side, it's a big turn-off for those who think you shouldn't have to take drugs to achieve your sporting goals [cue heated mess-tent discussions about why Diamox is considered a drug but Ginkgo Biloba isn't].
• Garlic. There is absolutely no evidence that garlic mitigates the symptoms of AMS. It is hard to prove this though, because those well enough to eat garlicky food are clearly not suffering AMS, so they skew the sample.
• Reaaalllly slow acclimatisation. If you have time on your hands, then you may be able to avoid AMS by prolonging the whole acclimatisation process. It's an expensive option, and not available to most climbers. Plus most people seem to have a certain altitude at which they get AMS whatever happens. Fine if you are Reinhold Messner and that figure is 9000m; not so good for the rest of us.
• Mild AMS. Yup, as long as you don't start scoring too high on the AMS score-card, you could just grin and bear it. A good option for those who really don't like sticking any pharmaceuticals, neutriceuticals or any other sort of -ceuticals into themselves. A less good option for their companions, who will have to put up with a pale, sweating grouch.
• Rock climbing. Rock climbing is really good fun, and you can do it at sea level. If you really can't be bothered with all this AMS stuff, Ginkgo or Diamox, but you still want to climb, then forget the high mountains and just go rock-climbing. It's cheaper too (marginally).

AMS and Ginkgo Biloba Links

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Aim4Health.

An online provider of Ginkgo - offering "a healthy body, a healthy mind and a healthy spirit". You decide. They claim their Ginkgo is "activated", or rendered water soluble by a patented process. So far so good. However, owners Gloria and Jay Smith describe themsleves as "Health Ministers". This is where I start to get nervous.

British Mountaineering Council

Information on Altitude Sickness and AMS

Everest Base Camp Clinic

The website of the highest medical clinic in the world (5500m). What these guys don't know about AMS, HACE, HAPE, diarrhea and vomiting is simply not worth knowing. Also good for the latest info on Diamox and Ginkgo.

High Altitude Medicine Guide

Altitude Illness Clinical Guide for Physicians. Very detailed and up-to-date information, may be a bit too technical for the layman. But if you are going to altitude, you owe it to yourself to understand the medical issues associated. If you are a generally smart person, then get a medical friend (preferably a climber) to go through this site with you.

Holland and Barratt (UK)

The UK's leading high street chain for unproven pseudo-medicines. But a good place to buy your Ginkgo Biloba, which they stock in most stores. Get the 120mg capsules - you'll need two per day, starting one week before your departure. At the time of writing, 100 capsules, usually £32.99 was on sale for £16.49.

Goethe's Poem "Ginkgo Biloba"

Yes, Goethe actually wrote a poem about Ginkgo Biloba, which he read to Marianne von Willemer on 15 September 1815. Later he wrote it out, attached two ginkgo leaves from a tree in the grounds of Heidelberg Castle, and sent it to her. Judging from the surviving pictures of Marianne, frankly, he would have been better off eating the leaves and going climbing.

The Ginkgo Pages

Dutchman Cor Kwant "created this site because of [his] fascination and respect for this unique tree, a living fossil, unchanged since the time of the dinosaurs. It is the sole living link between the lower and higher plants, a symbol of longevity and is seen as one of the wonders of this world." Cor, you are a jewel.

Web Vitamins (US)

Buy your Ginkgo Biloba online in the US. Get the 120mg capsules - you'll need two per day, starting one week before your departure. At the time of writing, the retail price for 120 capsules was $29.95, online price $21.60 plus package and posting. Proving that things are cheaper in the US, though not necessarily better.