The benefits of Ginkgo biloba for athletes: the evidence base

Ginkgo biloba often ends up in pre-workout and "nootropic" complexes with promises of better circulation, endurance and concentration. But what of this has actually been tested in humans, and what is extrapolation from laboratory models? The editorial team has gathered the key studies related to physical activity and assessed how convincing they are.

Why ginkgo interests athletes at all

Interest in ginkgo in sport grew out of two ideas. The first is vascular: the extract dilates small vessels and improves blood rheology, so theoretically it could improve oxygen delivery to working muscles. The second is cognitive: if ginkgo improves attention, it could help in games and sports where reaction and concentration are decisive.

A third argument often cited is the antioxidant action. Intense training is accompanied by oxidative stress, and supplement manufacturers readily offer flavonoids as a "protection" for muscles. However, modern sports science treats large doses of antioxidants with caution: some of the signals for adaptation to training are actually triggered by free radicals.

Finally, ginkgo has been studied for decades as a remedy for mountain sickness, which directly concerns climbers, trekkers and athletes who train at altitude. This very topic has the best-quality evidence base — and, as we will see, it does not favor ginkgo.

It is important to understand the limitations: the vast majority of clinical studies of ginkgo were conducted in elderly people, not in trained athletes. Effects found in patients with circulatory or memory disorders will not necessarily appear in a young, healthy body.

Aerobic endurance and physical performance

There are few direct studies of ginkgo's effect on athletic performance, and they are small. The Polish work by Sadowska-Krępa and colleagues is most often cited: physically active young men took ginkgo extract or placebo for six weeks, while the researchers assessed aerobic performance, antioxidant status and the level of brain-derived neurotrophic factor (BDNF).

The authors reported an improvement in the maximum oxygen uptake and an increase in BDNF in the ginkgo group. The result is interesting, but the sample was small and the study was a single one. Until it is independently reproduced in other laboratories, such data should be regarded as a hypothesis rather than proof.

Indirect information is provided by the Cochrane review on intermittent claudication — a condition in which, due to narrowing of the leg arteries, a person cannot walk a long distance without pain. Here ginkgo should demonstrate its vascular properties most vividly. However, the review found no clinically significant increase in walking distance compared with placebo.

If even in patients with impaired blood flow the effect on performance is not obvious, then in healthy athletes with a well-developed vascular network it is even harder to count on a noticeable gain in endurance.

Altitude and mountain sickness

The idea of using ginkgo to prevent acute mountain sickness appeared after several small studies of the 1990s and early 2000s in which the extract showed a certain protective effect. It was attractive because ginkgo is sold over the counter and is considered a mild remedy.

The answer was given by the randomized double-blind PHAIT study, published in the BMJ in 2004. Among several hundred trekkers in the Himalayas, ginkgo did not differ from placebo in the incidence of mountain sickness, whereas acetazolamide substantially reduced the risk.

Subsequent works gave contradictory results, some of which are attributed to differences in extract quality. Summarizing the data, the clinical guidelines of the Wilderness Medical Society do not recommend ginkgo for the prevention of acute mountain sickness.

The practical conclusion for athletes and tourists is obvious: ginkgo should not replace gradual acclimatization and proven prevention methods, which are discussed with a doctor before the trip.

Attention, reaction and cognitive function

Cognitive studies of ginkgo in young healthy people are mostly short-term. In the work by Kennedy and colleagues in 2000, participants received single doses of 120, 240 and 360 mg of extract; the researchers recorded an improvement in attention speed a few hours after intake, and the nature of the effect depended on the dose and the time of measurement.

At the same time, in the study by Solomon and colleagues published in JAMA in 2002, six weeks of taking 120 mg per day by healthy people over 60 years old did not improve memory, attention or information-processing speed compared with placebo. The large multi-year GEM trial and the subsequent analysis by Snitz and colleagues also found no slowing of cognitive aging.

For an athlete, this means there are no grounds to count on a noticeable "nootropic" effect of ginkgo during competition. Sleep, nutrition, caffeine in moderate doses and skills training have a far more convincing basis.

How to evaluate such data

When we talk about a supplement's evidence base, what matters is not the number of publications but their quality. A small study with a positive result carries far less weight than a large randomized trial with a negative one. Moreover, in herbal products the quality of the raw material critically affects the outcome.

To evaluate any claim about ginkgo, we recommend paying attention to several questions:

1. Was it specifically the standardized extract that was studied, and at what dose?
2. Who were the participants — elderly patients or trained young people?
3. How many participants were there, and was the study double-blind and placebo-controlled?
4. Was a real athletic result measured, and not just biochemical markers?
5. Has the result been reproduced by independent groups?

By these criteria, the sports data on ginkgo do not yet reach the level at which confident recommendations can be given.

Editorial conclusions

The evidence base for the benefits of ginkgo biloba for athletes is weak. Isolated positive results regarding aerobic performance require reproduction, and the highest-quality studies — on mountain sickness and on memory in healthy people — showed no effect.

Ginkgo is not a doping agent and is not on the WADA Prohibited List, so there are no formal restrictions. However, the absence of a ban does not mean the presence of a benefit.

If an athlete still decides to try ginkgo, it is worth choosing a standardized extract and remembering the effect on blood clotting — especially in contact sports and before surgery.

The editorial team also recommends reviewing the materials "Ginkgo biloba: what it is and how it works", "Myths about Ginkgo biloba" and "The benefits of Bacopa monnieri for athletes: the evidence base".

References

1. Sadowska-Krępa E, et al. Effects of six-week Ginkgo biloba supplementation on aerobic performance, blood pro/antioxidant balance, and serum brain-derived neurotrophic factor in physically active men. Nutrients. 2017.
2. Nicolaï SP, Kruidenier LM, Bendermacher BL, et al. Ginkgo biloba for intermittent claudication. Cochrane Database Syst Rev. 2013;(6):CD006888.
3. Gertsch JH, Basnyat B, Johnson EW, Onopa J, Holck PS. Randomised, double blind, placebo controlled comparison of ginkgo biloba and acetazolamide for prevention of acute mountain sickness among Himalayan trekkers: the prevention of high altitude illness trial (PHAIT). BMJ. 2004;328(7443):797.
4. Luks AM, Auerbach PS, Freer L, et al. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness: 2019 Update. Wilderness Environ Med. 2019;30(4S):S3–S18.
5. Kennedy DO, Scholey AB, Wesnes KA. The dose-dependent cognitive effects of acute administration of Ginkgo biloba to healthy young volunteers. Psychopharmacology (Berl). 2000;151(4):416–423.
6. Solomon PR, Adams F, Silver A, Zimmer J, DeVeaux R. Ginkgo for memory enhancement: a randomized controlled trial. JAMA. 2002;288(7):835–840.
7. DeKosky ST, Williamson JD, Fitzpatrick AL, et al. Ginkgo biloba for prevention of dementia: a randomized controlled trial. JAMA. 2008;300(19):2253–2262.
8. Snitz BE, O'Meara ES, Carlson MC, et al. Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial. JAMA. 2009;302(24):2663–2670.