What Does Science Say About Ginkgo Biloba’s Health Benefits?

Written by Andy Mobbs
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Ginkgo Biloba has a long history in traditional Chinese medicine. The hype surrounding its purported health benefits is widespread not just in the West, but all over the world. But how much of it is actually based on facts and science? Find out as we dive deep into the world of the Ginkgo Biloba.

But first, to give you an idea of what to expect in this article, here are some of the most important highlights or benefits of taking Ginkgo:

  • Ginkgo causes vasodilation of the blood vessels which leads to improved blood flow to the brain
  • Ginkgo can improve memory
  • Ginkgo supports neuronal health, mitochondrial health, and levels of the neurotransmitters dopamine, noradrenaline, serotonin, and acetylcholine

What is Ginkgo Biloba?

Ginkgo Biloba is quite literally an ancient tree. It’s the only survivor of an ancient group of trees that date back to before dinosaurs walked on earth, some 245 million years ago. Because of that, Ginkgo trees are sometimes called living fossils.

Ginkgo trees can reach 40 meters in height, with some of them thought to be over 1500 years old. The ancient trees were revered so much they were also used for shamanic worship. Daoist shamans engraved magical spells and seals on the oldest trees in order to communicate with the spirit world.

Also, eyewitness reports from Hiroshima and Nagasaki where the atom bombs were dropped at the end of the 2nd world war, suggest that only Ginkgo trees and cockroaches were able to survive and thrive in the areas most affected by radiation (1, 2).

Ginkgo has also been a part of Chinese medicine for 2000 years where it was used for a number of issues. It was used to treat asthma, kidney problems, skin problems, and even brain aging issues that today we would probably call dementia.

What are the active compounds in Ginkgo Biloba?

Ginkgo has a number of active compounds including Ginkgolides, Flavanoids, and Quercetin:

Ginkgolides have been shown to inhibit platelet activation in the blood. Platelets are cell fragments that when activated cause red blood cells to stick to each other and this can cause clots and reduce blood flow (3).

Ginkgo flavonoids have been shown to stimulate an antioxidant response in the body by causing increased production of the body’s main antioxidants glutathione, SOD, and catalase (4, 5).

Quercetin has a number of antioxidant and anti-inflammatory properties. It has been shown to have a potential role in reducing the risk of a wide number of disorders including neurodegenerative disorders, cancer, cardiovascular diseases, allergic disorders, thrombosis, atherosclerosis, hypertension, and arrhythmia (6).

What are the health benefits of Ginkgo Biloba?

The active compounds in Ginkgo are directly responsible for the following health benefits:

infographic on reasons to take ginkgo biloba supplement

#1 – Neuroprotection

These anti-inflammatory and antioxidant properties have shown that Ginkgo can protect brain neurons and stop them from dying.

For example, when researchers either induce Alzheimer’s in rats by injecting a substance called Amyloid β-Peptide into their brain or by creating strokes in the rats, supplementation with Ginkgo can actually protect neurons and stop them from dying (7, 8). Amyloid β-Peptide is an insoluble protein that aggregates in neuronal cells stopping their correct functioning and is strongly associated with Alzheimer’s and dementia.

Unfortunately, these studies have only been conducted in animals because to see the effects of the experiments on brain cells, the animals need to have their brains dissected, so it’s unlikely the studies will ever be done in humans!

#2 – Mitochondrial Stability

Another key role that ginkgo can potentially play is the stabilization of the mitochondria by reducing their production of free radicals. This reduces stress on them and can stop them from dying off. Mitochondria are the engines of our cells by producing energy, we have around 2000 of them in each cell. But they are very prone to damage as they produce free radicals to make energy.

Ginkgo has been shown to stabilize mitochondrial membranes and also prevent the membrane release of cytochrome c and stop the production of Caspase 3 and 9. Both the Caspases and cytochrome C release from the membrane signal apoptosis which is cellular suicide where the cell destroys itself (9-12).

#3 – Endothelial Vasodilation

The cells that line our blood vessels, i.e the arteries, veins, and capillaries, are called the endothelial cells. Endothelial cells are required to constrict and relax to change our blood pressure depending on what activities we need to accomplish. It also allows oxygen, proteins, fats, vitamins, and minerals amongst many other things to diffuse in and out of the bloodstream.

However, whenever there is an increase in inflammation it becomes more difficult to relax the endothelial cells and increase blood flow. Ginkgo has been shown to be able to relax endothelial cells and cause vasodilation improving blood flow (13).

#4 – Dopamine, Noradrenaline, and Serotonin

Dopamine, serotonin, and noradrenaline are all known as catecholamine neurotransmitters and are closely related to each other. They are broken down by the same enzymes, the monoamine oxidases. Dopamine is associated with focus and motivation, Noradrenaline with focus and energy, and Serotonin with positive feelings.

Ginkgo has been shown to inhibit the monoamine oxidases, which stop these neurotransmitters from being broken down, allowing blood levels of them to rise.

#5 – Acetylcholine

Acetylcholine is often called the ‘smart’ neurotransmitter due to its association with learning and memory. The drug scopolamine inhibits acetylcholine by blocking its receptors and can have a strong effect on reducing both memory and physical movement which both require acetylcholine to work properly.

Researchers can therefore use scopolamine in animal studies to judge how well certain compounds increase acetylcholine. If scopolamine still causes memory loss, then whatever other molecule they are testing is not affecting acetylcholine levels. Ginkgo, however, has been shown to inhibit the memory reduction caused by scopolamine administration in rats, therefore it increases acetylcholine (15).

In fact, further research has shown ginkgo supplementation exerts the effects of acetylcholine in 2 ways. First, it increases the number of acetylcholine receptors (16), and secondly, it prevents choline reuptake by the presynaptic neurons in nerve synapses (17).

Interestingly, research has also shown that Ginkgo can inhibit the gradual reduction in serotonin receptors in the hippocampus that is known to happen with age, and that these serotonin receptors can actually stimulate acetylcholine release (18).

chemical synapse

#6 – Nootropic Effects

There have been a number of studies done on Ginkgo and its effects on cognitive function. For example, Heiss and Zeiler first found that Ginkgo increased cerebral blood flow by about 8.4% in 1978 (19), and Tea et al in 1979 found it increases oxygen and glucose consumption in subjects with neurologic ischaemic syndrome (i.e. a reduction in blood flow), who took ginkgo as a supplement (20).

Ginkgo Biloba is one of the ingredients in our nootropic stack, Seneca Nootropic. Each serving of Seneca contains 120mg of Ginkgo taken from 6000mg 50:1 whole plant extract.

Related article: What Are Nootropics?

#7 – Memory

A study at the University of Surrey in England tested 31 healthy volunteers between 30 and 59 years of age at a range of different Ginkgo doses 120mg, 150mg, 240mg, and 300mg as well as with placebo. All of the volunteers tried each of the doses, and each of the supplementation periods lasted for 2 days.

Even though the supplementation period only lasted for 2 days they found significant increases in reaction time, short-term memory, and working memory scores for ginkgo supplementation over placebo, with the best dose being 120mg per day (c). Another study found there was a significant improvement in memory with a dose of 600mg of Ginkgo, with the subjects only being tested 1 hour after taking the supplement! (22)

A further study tested 188 healthy subjects between 45 and 56 years old with either 240mg of Ginkgo per day or placebo for 6 weeks. They found a significant improvement in the ginkgo group in a memory test known as ‘free recall’, which is a challenging test that requires subjects to remember a long list of items (23).

supplementing with ginkgo biloba can help with memory

#8 – Cognitive Decline

A study based in London tested subjects who were over 50 and generally physically healthy but showing mild to moderate symptoms of memory impairment. The subjects were given 120mg of Ginkgo per day and then they were tested on cognitive function tests, including a speed copying test and an object classification test, before they started supplementation, and then at 12 weeks and 24 weeks.

The researchers found that there was a significant improvement in speed copying at 12 and 24 weeks and a significant improvement on the classification test at 24 weeks (24).

#9 – Well Being and Alertness

A large study followed 1570 men and women who took either a placebo or 120mg of Ginkgo daily for 4, 6 or 10 months. The subjects were tested in a number of different ways including subjective scoring of how well they could deal with daily life, how good their mood was, and how alert they felt throughout the day.

The researchers found that ginkgo improved scores on all the tests including reducing anxiety, and they also found that the longer you took ginkgo the better the effect was (25).

#10 – Alzheimers and Dementia

Ginkgo has been used in a number of placebo-controlled studies for Alzheimer’s and dementia patients. So far the results have been somewhat mixed. However, it is important to remember that so far the pharmaceutical drugs that have been approved for dementia treatment have only had a modest effect in slowing its progression.

For example, one review of eight randomized double-blind studies found that Ginkgo has a small effect on improving the symptoms of dementia and cerebral insufficiency, which were similar in effect to the drug Hydergine at a dosage of 120mg of Ginkgo per day for 4-6 weeks (26).

A further review paper looked at studies that had lasted for at least six months in duration and found that ginkgo, when compared to 4 different second-generation cholinesterase inhibitors, had a similar level of effectiveness in treating mild to moderate Alzheimer’s / dementia (27). Cholinesterase inhibitors are a type of drug used to treat dementia that inhibits the enzyme cholinesterase which breaks down acetylcholine.

What are the side effects of Ginkgo Biloba?

Ginkgo is generally well tolerated with few reported side effects beyond mild ones that include nausea, diarrhea, dizziness, and headaches.

However, it can interact with ‘blood thinner’ medications such as warfarin or diabetes medication. So if you are taking prescription medication, please do speak to your doctor first.

References

(1) François Chassagne, Xinyi Huang, James T. Lyles and Cassandra L. Quave, Validation of a 16th Century Traditional Chinese Medicine Use of Ginkgo biloba as a Topical Antimicrobial, Front. Microbiol., 16 April 2019

(2) Subhuti Dharmandanda, Heiner Fruehauf, Ginkgo: Cultural Background and Medicinal Usage in China, https://classicalchinesemedicine.org/ginkgo-cultural-background-and-medicinal-usage-in-china/

(3) Nong-Jian Guo , Ya-Li Chang, Dong-Jie Xiao, Ping Huang, Activation of platelet-neutrophil mediated by platelet-activating factor, Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2005 Jun;13(3):447-51.

(4) K Gohil , R K Moy, S Farzin, J J Maguire, L Packer, mRNA expression profile of a human cancer cell line in response to Ginkgo biloba extract: induction of antioxidant response and the Golgi system, Free Radic Res. 2000 Dec;33(6):831-49.

(5) Bridi R, Crosetti FP, Steffen VM, Henriques AT. The antioxidant activity of standardized extract of Ginkgo biloba (EGb 761) in rats. Phytother Res. 2001;15:449–451

(6) Preetham Elumalai, Sreeja Lakshmi, Role of Quercetin Benefits in Neurodegeneration, Adv Neurobiol. 2016;12:229-45.

(7) Yin Y, Ren Y, Wu W, et al. Protective effects of bilobalide on Aβ(25–35) induced learning and memory impairments in male rats. Pharmacol Biochem Behav. 2013;106:77–84.

(8) Jiang M, Li J, Peng Q, et al. Neuroprotective effects of bilobalide on cerebral ischemia and reperfusion injury are associated with inhibition of pro-inflammatory mediator production and down-regulation of JNK1/2 and p38 MAPK activation. J Neuroinflammation. 2014;11:167

(9) Schindowski K, Leutner S, Kressmann S, Eckert A, Muller WE. Age-related increase of oxidative stress-induced apoptosis in mice prevention by Ginkgo biloba extract (EGb761) J Neural Transm. 2001;108:969–978.

(10) Smith JV, Burdick AJ, Golik P, Khan I, Wallace D, et al. Anti-apoptotic properties of Ginkgo biloba extract EGb 761 in differentiated PC12 cells. Cell MolBiol (Noisy-le-grand) 2002;48:699–707.

(11) Leuner K, Hauptmann S, Abdel-Kader R, Scherping I, Keil U, et al. Mitochondrial dysfunction: the first domino in brain aging and Alzheimer’s disease? Antioxid Redox Signal. 2007;9:1659–1675.

(12) Abdel-Kader R, Hauptmann S, Keil U, Scherping I, Leuner K, et al. Stabilization of mitochondrial function by Ginkgo biloba extract (EGb 761) Pharmacol Res. 2007;56:493–502.

(13) DeFeudis FV. Ginkgo biloba extract (EGb 761): pharmacological activities and clinical applications. Amsterdam: Elsevier, 1991:1187.

(14) White H. L., Scates P. W., Cooper B. R. Extracts of Ginkgo biloba leaves inhibit monoamine oxidase. Life Sci 1996; 16: 1315–1321.

(15) Choppin P., Briley M. Effects of four non-cholinergic cognitiveenhancers in comparison with tacrine and galanthamine on scopolamine induced amnesia in rats. Psychopharmacol 1992;106: 26–30.

(16) Taylor J. E. Neuromediator binding to receptors in the rat brain. The effect of chronic administration of Ginkgo biloba extract. Presse Med 1986; 15: 1491–1493.

(17) Kristoflikova Z., Klaschka J. In vitro effect of Ginkgo biloba extract (Egb 761) on the activity of pre-synaptic cholinergic nerve terminals in rat hippocampus. Dement Geriatr Cogn Disord 1997; 8(1): 43–48.

(18) Huguet F., Drieu K., Piriou A. Decreased cerebral 5-HT1A receptors during aging: reversal by Ginkgo biloba extract (EGb 761). J Pharm Pharmacol 1994; 46: 316–318.

(19) Heiss, W. D., and Zeiler, K. (1978). Medikamentose Beein-ussung der Hirndurchblutung. Pharmakotherapie 1,137±144

(20) Tea, S., Celsis, P., Clanet, M., and Marc-Vergnes, J. (1979). Effets cliniques hemodynamiques et metaboliques del’extrait de Ginkgo biloba en pathologie vasculaire cerebrale. Gaz. Med. (France) 86, 4149±4152.

(21) U. Rigney, S. Kimber and I. Hindmarch, The Effects of Acute Doses of Standardized Ginkgo biloba Extract on Memory and Psychomotor Performance in Volunteers, Phytother. Res. 13, 408–415 (1999)

(22) Subhan Z., Hindmarch I. The psychopharmacological effects of Ginkgo biloba extract in normal healthy volunteers. Int J Clin Pharm Res 1984; IV(2): 89–93.

(23) R Kaschel, Specific memory effects of Ginkgo biloba extract EGb 761 in middle-aged healthy volunteers, Randomized Controlled Trial Phytomedicine. 2011 Nov 15;18(14):1202-7.

(24) Rai, GS, Shovlin,C, Wesnes, KA, A double-blind, placebo controlled study of Ginkgo biloba extract (‘Tanakan’) in elderly outpatients with mild to moderate memory impairment, Current Medical Research and Opinion Vol. 12, No. 6,1991

(25) Leanne Trick, Julia Boyle, Ian Hindmarch, The effects of Ginkgo biloba extract (LI 1370) supplementation and discontinuation on activities of daily living and mood in free living older volunteers, Clinical Trial Phytother Res. 2004 Jul;18(7):531-7.

(26) Kleijnen J, Knipschild P. Ginkgo biloba for cerebral insufficiency. Br J Clin Pharmacol 1992;34:352-8.

(27) Wettstein A. Cholinesterase inhibitors and Ginkgo extracts — are they comparable in the treatment of dementia? Comparison of published placebo-controlled efficacy studies of at least six months’ duration. Phytomedicine 2000;6:393-401.