Ginkgo biloba

The ginkgo tree grows 30 m to 40 m high and is a deciduous tree. In terms of evolutionary history, it is one of the oldest plant species on earth and represents the link between ferns and conifers. The leaves turn golden yellow in the fall. Originally native to China, Korea and Japan, the tree is increasingly being planted in Europe, as it appears to be very resistant to harmful environmental influences. The ginkgo is dioecious, i.e. there are male and female plants. The name biloba = two-lobed refers to the typical leaf shape. Special extracts from the leaves are used medicinally, and the seeds are also used in traditional Chinese medicine.

Application

Extracts from ginkgo leaves

• Brain disorders,
• Peripheral arterial circulatory disorders
• ringing in the ears, dizziness
• Altitude sickness
• Short and long-term memory
• Exhaustion, depression, anxiety disorders and headaches.

Research

Over the last 30 years, more than 300 research reports have explained the benefits of Ginkgo biloba. Various studies have shown that it can prevent numerous physical complaints or positively influence processes in the body. It has been studied as an active ingredient in the treatment of Alzheimer's disease and other impairments of brain function.

In clinical studies, a positive effect has so far only been demonstrated for ginkgo extracts obtained from the leaves with an acetone-water mixture (DEV 35-67:1). These extracts are adjusted to about 25% flavonoid glycosides (flavonols and biflavones) and about 6% terpene lactones (ginkgolides A, B, C and bilobalide), whereby the content of ginkgolic acids, which are highly irritating to the skin and can lead to gastric intolerance, should be below 5 ppm.

The following effects have been experimentally proven

• Increasing the tolerance of brain tissue in particular to oxygen deficiency
• Promotion of blood circulation in the brain
• Improvement of the flow properties of the blood
• Inhibition of PAF (platelet aggregation factors)
• Influencing central neurotransmitters
• Inactivation of harmful radicals

Potential health benefits

Ginkgo Biloba is rich in powerful antioxidants

Ginkgo's antioxidant content may be the reason for many of its health benefits (1). Ginkgo contains large amounts of flavonoids and terpenoids, which are known for their powerful antioxidant effects (2).

Antioxidants are compounds that neutralize free radicals and prevent their harmful effects. Free radicals are highly reactive particles produced by the body as part of normal metabolic functions such as energy production or detoxification. Free radicals have the potential to damage healthy body tissues and contribute to both the ageing process and the development of numerous diseases.

Scientific research into the antioxidant effects of ginkgo is promising. However, it remains unclear how they work and how effective they are when it comes to treating disease. Ginkgo can help fight inflammation. Inflammation is a normal part of the body's response to injury or foreign substances entering the body. During an inflammatory response, different components of the immune system are recruited to fight against these foreign substances or to heal the injured area. Some chronic diseases are caused by inflammatory reactions, which can also occur without injury or foreign substances. Over time, excessive inflammation can cause permanent damage to body tissue or DNA. Years of scientific research in test tubes and animals have shown that ginkgo extracts can reduce inflammatory markers in human and animal cells at different stages of disease (3, 4).

Specific diseases for which ginkgo extracts have been shown to be effective in reducing inflammation include

• Arthritis
• Irritable bowel syndrome
• cancer
• heart disease
• stroke

Although these data are encouraging, further human studies are needed before any firm conclusions can be drawn about the anti-inflammatory properties of ginkgo.

Ginkgo improves blood circulation and can promote heart health

In traditional Chinese medicine, ginkgo seeds have been used to open "channels" of energy to various organ systems including the kidneys, liver, brain and lungs. Ginkgo's ability to improve blood flow to different areas of the body may be the source of many of its purported health benefits. A study of subjects with heart disease who supplemented with ginkgo showed an immediate increase in blood flow to several parts of the body. This was attributed to a 12% increase in the amount of circulating nitric oxide - a compound responsible for dilating blood vessels (5). Another study of adults treated with a ginkgo extract showed the same effects (6). Additional research points to the heart-protective effects, a protective effect on brain health and protection against strokes. There are several potential explanations for this, one of which is related to the anti-inflammatory compounds contained in ginkgo (7, 8).

Ginkgo may reduce symptoms of mental disorders and dementia

Ginkgo has been repeatedly studied for its ability to reduce anxiety, stress and other symptoms associated with Alzheimer's disease and age-related cognitive decline. Overall, the data in this area is inconsistent. Some studies show a significant decrease in age-related decline in cognitive function in dementia patients using ginkgo, while other studies have failed to replicate these results. A review of 21 studies concluded that ginkgo, when used in conjunction with conventional medicine, could improve functional capacity in patients with mild cases of Alzheimer's disease (9).

Another review found a significant reduction in the range of symptoms associated with dementia when ginkgo was used for 22 to 24 weeks (10). These positive results may be related to the role that ginkgo may play in improving blood flow to the brain, which is especially true when it comes to vascular types of dementia.

Ginkgo can reduce anxiety

Some research suggests that ginkgo supplementation may reduce symptoms of anxiety.

A handful of studies conducted with animals observed reductions in anxiety symptoms, which could be attributed to the antioxidant content of ginkgo (13). In another study, 170 subjects with generalized anxiety symptoms were treated with either 240 mg or 480 mg of ginkgo or a placebo. The group treated with the highest amount of ginkgo reported a 45% greater reduction in their anxiety compared to the placebo group (14).

Ginkgo improves brain function and well-being

There is some speculation that ginkgo may improve brain function in healthy people. A handful of studies support the view that supplementing with ginkgo could boost mental performance and improve perceived well-being (11). Results from studies like these have led to ginkgo being associated with improved memory performance, better focus and a longer attention span. However, one study review concluded that ginkgo did not result in measurable improvements in memory, executive function or attention (12). Although supplementation with ginkgo may increase mental capacity, there are no guarantees.

Ginkgo may help in the treatment of depression

A review of animal studies suggests that ginkgo supplementation may help alleviate symptoms of depression (15). Mice that received ginkgo before an unavoidable stressful situation were less emotionally affected by the stress than the group that did not receive ginkgo. The study suggested that this effect was related to the anti-inflammatory effects of ginkgo, which improve the body's ability to cope with high levels of stress. However, depression is a complex disorder that can have a number of causes, so further research is needed to determine the relationship between ginkgo and stress in humans.

Ginkgo can support vision and eye health

There are few studies that have examined the effects of ginkgo on vision and eye health, but the results are promising. One review showed that people suffering from glaucoma who supplemented with ginkgo had increased blood flow to the eye, but this was not necessarily reflected in improved vision (16). Another review of two studies examined the effects of ginkgo on the progression of age-related macular degeneration. Some study participants reported improved vision, but this effect was not statistically significant (17). Many of these positive effects appear to be related to increased blood flow to the eye.

It is also unclear whether ginkgo can improve vision in people who do not already suffer from impaired vision.

Ginkgo can treat headaches and migraines

In the field of traditional Chinese medicine, ginkgo is very popular when it comes to treating headaches and migraines. While there is limited research on ginkgo's abilities, depending on the cause of the headache, ginkgo may help.

For example, it is well known that ginkgo has antioxidant and anti-inflammatory effects. If headaches are caused by stress, then ginkgo could help. In addition, if headaches are related to reduced blood flow or constricted blood vessels, ginkgo's ability to dilate the veins may help. In contrast, some migraine attacks are caused by excessive dilation of blood vessels. In this situation, ginkgo may have no effect.

However, this is only conjecture and not hard evidence. If you want to try ginkgo for headaches, it is unlikely to do any harm.

Ginkgo can relieve symptoms of asthma and COPC

Some research suggests that ginkgo may reduce symptoms of asthma and other inflammatory diseases of the airways such as COPD. This is attributed to the anti-inflammatory compounds in ginkgo, which may allow a reduction in airway inflammation and increase lung capacity (18). A study of 75 subjects evaluated the use of ginkgo extracts in combination with glucocorticoid medication for the treatment of asthma symptoms (19). The levels of inflammatory compounds in the mucus of those who received ginkgo were significantly lower than those who received only the traditional medication. Another study of 100 subjects investigated the use of a mixture of Chinese herbs including ginkgo in the treatment of COPD symptoms. Those who used the herbal mixture reported a significant reduction in cough and bronchitis compared to the control group (20).

At this time, it cannot be determined if this improvement can be attributed to ginkgo alone or if it was a synergistic effect of the entire herbal blend.

Ginkgo can reduce PMS symptoms

Preliminary research suggests that ginkgo may help alleviate the physical and psychological symptoms of premenstrual syndrome (PMS). A study of 85 female college students showed a 23% reduction in reported PMS syndromes after consuming ginkgo (21).

Interestingly, the placebo group also experienced a slight reduction in symptoms, but this was much lower at 8.5%.

Ginkgo could be used to treat sexual dysfunction

Some sources suggest that ginkgo could treat sexual dysfunctions such as erectile dysfunction or reduced libido. Ginkgo has the ability to increase blood levels of nitric oxide, which can improve blood circulation by widening the veins (5). As a result, ginkgo may be helpful in treating various symptoms of sexual dysfunction by increasing blood flow to the appropriate areas of the body. Some studies have investigated the use of ginkgo to treat sexual dysfunction caused by antidepressants (selective serotonin reuptake inhibitors). The results indicated that ginkgo was no more effective than a placebo in these cases. There may also be an interaction between ginkgo and these antidepressants that makes them less effective. One study investigated the use of ginkgo to increase sexual desire and satisfaction in women who were undergoing sexual psychotherapy at the time (22). In the long term, the combination of ginkgo and therapy was more effective than a placebo, but ginkgo alone was not. The rationale for using ginkgo to treat sexual dysfunction makes sense, but there are no studies to support this yet.

Need in sport

Of its many beneficial properties, one ability in particular is likely to interest bodybuilders: The promotion of blood circulation and thus a more effective workout. Ginkgo biloba improves blood flow to the brain and muscles. The better the blood circulation, the better the muscles are supplied with oxygen, nutrients and hormones. In addition, waste products and toxins are flushed out more quickly, which speeds up regeneration after training. Ginkgo biloba is also reported to act as an antioxidant and stimulate the metabolism. Any boost to metabolic processes, however minimal, is welcome in terms of burning calories and increasing muscle mass.

Dosage

My recommendation is to take a dose of 40-200mg spread over 3 single doses. In general, 60mg three times a day is a good rule of thumb. Doses up to 240mg per day are suitable for people with memory impairment, confusion and/or depression.

Safety and side effects

Ginkgo biloba leaf extract is probably safe and harmless for most people when taken orally in appropriate doses. It may cause some mild side effects such as stomach upset, headache, dizziness, constipation, palpitations and allergic skin reactions. There are concerns that Ginkgo biloba leaf extract may increase the risk of liver and thyroid cancer. However, this has only occurred in animals given extremely high doses of Ginkgo biloba. There is not enough information on whether this could also happen in humans. The Ginkgo biloba fruit and pulp can cause serious allergic skin reactions and irritation of the mucous membranes. Ginkgo biloba could cause allergic reactions in people who are allergic to poison ivy, poison oak, poison sumac, mango bark or cashew oil. There are concerns that Ginkgo biloba leaf extract may increase the risk of bruising and bleeding. Ginkgo biloba thins the blood and reduces its ability to clot. Some people who have taken Ginkgo biloba have experienced bleeding in the eyes and brain, as well as excessive bleeding after surgery. Ginkgo biloba leaf extract can cause allergic skin reactions in some people. The roasted seeds and the raw Ginkgo biloba plant may not be safe and harmless when taken orally. Consuming more than 10 roasted seeds per day can cause difficulty breathing, weak pulse, seizures, unconsciousness and shock. The fresh seeds are even more dangerous. Fresh Ginkgo biloba seeds are poisonous and eating them can cause seizures and death.

Not enough is known about the safety and harmlessness of Ginkgo biloba applied to the skin.

Precautions and warnings

• Pregnancy and lactation: Ginkgo biloba may not be safe for use during pregnancy. Ginkgo biloba could cause premature birth or additional bleeding during childbirth if used close to the due date. Not enough is known about the safety and harmlessness of Ginkgo biloba during breastfeeding. For these reasons, pregnant and breastfeeding women should not use Ginkgo biloba.
• Children: Ginkgo biloba leaf extract may be safe for children. Some research suggests that a specific combination of Ginkgo biloba leaf extract and American ginseng may be safe for short-term use by children. Children should not be allowed to eat Ginkgo biloba seeds, as Ginkgo biloba seeds are not safe and harmless.
• Diabetes: Ginkgo biloba may interfere with the treatment of diabetes. For this reason, diabetics should carefully monitor their blood sugar levels when using Ginkgo biloba. Seizures: There are concerns that Ginkgo biloba may cause seizures. For this reason, you should not use Ginkgo biloba if you have ever had seizures. Infertility: Using Ginkgo biloba could make it harder for women to get pregnant. For this reason, women who are trying to conceive should discuss the use of Ginkgo biloba with their doctor.
• Blood clotting disorders: Ginkgo biloba could aggravate blood clotting disorders. For this reason, Ginkgo biloba should not be used if you suffer from blood clotting disorders. Operations: Ginkgo biloba could slow down blood clotting. There are concerns that this could increase the risk of bleeding during and after surgery. For this reason, the use of Ginkgo biloba should be stopped at least 2 weeks before planned operations.

Interactions

Ginkgo biloba should not be used in combination with the following medications Ibuprofen Ginkgo biloba can slow down blood clotting. Ibuprofen can also slow down blood clotting. Taking Ginkgo biloba in combination with ibuprofen could slow down blood clotting too much and increase the risk of bruising and bleeding.

Medications that slow down blood clotting

Ginkgo biloba can slow down blood clotting. Taking Ginkgo biloba in conjunction with medications that also slow blood clotting could increase the risk of bleeding and the tendency to bruise.

Some medications that can slow blood clotting include aspirin, diclofenac (Voltaren), naproxen and others.

Care should be taken when combining Ginkgo biloba with the following medications:

Buspirone

Ginkgo biloba appears to affect the brain. Buspirone also affects the brain. One person felt hyper and overexcited after taking Ginkgo biloba, buspirone and other medications. It is unclear whether this reaction was caused by Ginkgo biloba or the other drugs.

Fluoxetine

Taking Ginkgo biloba in combination with St. John's wort, other plant extracts and fluoxetine could cause irritability, nervousness, restlessness and agitation. This is also known as hypomania. It is not known whether this is a cause for concern if only Ginkgo biloba is taken in combination with fluoxetine.

Drugs that are broken down by the liver (cytochrome P450 1A2 (CYP1A2) substrates, cytochrome P450 2C9 (CYP2C9) substrates and cytochrome P450 2D6 (CYP2D6) substrates) Some drugs are broken down by the liver. Ginkgo biloba can reduce the rate at which the liver breaks down certain drugs. Taking Ginkgo biloba in combination with medications that are broken down by the liver can increase the effects and side effects of some medications. For this reason, you should consult your doctor before taking Ginkgo biloba if you are taking medication that is broken down by the liver.

Drugs that are broken down by the liver (cytochrome P450 2C19 (CYP2C19) substrates) Some drugs are broken down by the liver. Ginkgo biloba may accelerate the rate at which the liver breaks down certain drugs. Taking Ginkgo biloba in conjunction with drugs that are broken down by the liver may reduce the effects of some drugs. For this reason, you should consult your doctor before taking Ginkgo biloba if you are taking medication that is broken down by the liver.

Drugs that are broken down by the liver (cytochrome P450 3A4 (CYP3A4) substrates) Some drugs are broken down by the liver. Ginkgo biloba may affect the rate at which the liver breaks down certain drugs, leading to a range of effects and side effects. For this reason, you should consult your doctor before taking Ginkgo biloba if you are taking medication that is broken down by the liver.

Diabetes medication

Diabetes medication is used to lower blood sugar levels. Ginkgo biloba could increase or reduce blood sugar levels in people suffering from type 2 diabetes. Taking Ginkgo biloba in combination with diabetes medication could reduce the effectiveness of the diabetes medication. For this reason, blood glucose levels should be carefully monitored. It is possible that the dosage of diabetes medication may need to be adjusted.

Medications that can increase the risk of seizures

Some medications can increase the risk of seizures. Taking Ginkgo biloba could cause seizures in some people. Taking medications that increase the risk of seizures in combination with Ginkgo biloba could greatly increase the risk of seizures. For this reason, Ginkgo biloba should not be taken in combination with drugs that increase the risk of seizures.

Medications used to prevent seizures (anticonvulsant medications)

Medications used to prevent seizures affect certain chemicals in the brain. Ginkgo biloba can also affect chemicals in the brain. As a result, Ginkgo biloba may reduce the effect of medications used to prevent seizures.

Trazodone

Trazodone affects chemicals in the brain. Ginkgo biloba can also affect chemicals in the brain. Taking trazodone in combination with ginkgo biloba can cause serious side effects in the brain. One person who took trazodone and ginkgo biloba fell into a coma. For these reasons, Ginkgo biloba should not be used when taking trazodone.

Care should be taken when combining Ginkgo biloba with the following medications:

Hydrochlorothiazide

Hydrochlorothiazide is used to help reduce swelling and control blood pressure. Taking hydrochlorothiazide in combination with Ginkgo biloba may increase blood pressure. Before taking Ginkgo biloba, you should talk to your doctor if you are taking medication for high blood pressure.

Omeprazole

Omeprazole is metabolized and broken down by the liver. Ginkgo biloba may increase the rate at which the liver breaks down omeprazole. Taking Ginkgo biloba in combination with omeprazole could reduce the effect of omeprazole.

References

1. https://www.ncbi.nlm.nih.gov/pubmed/11507743
2. https://www.ncbi.nlm.nih.gov/pubmed/16492481
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5758353/
4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2527648/
5. https://www.ncbi.nlm.nih.gov/pubmed/18446847
6. https://www.ncbi.nlm.nih.gov/pubmed/18258419
7. https://www.ncbi.nlm.nih.gov/pubmed/28333443
8. https://www.ncbi.nlm.nih.gov/pubmed/26059355
9. https://www.ncbi.nlm.nih.gov/pubmed/26268332
10. https://www.ncbi.nlm.nih.gov/pubmed/28931444
11. https://www.ncbi.nlm.nih.gov/pubmed/12404671
12. https://onlinelibrary.wiley.com/doi/full/10.1002/hup.2259
13. https://www.ncbi.nlm.nih.gov/pubmed/29168225
14. https://www.ncbi.nlm.nih.gov/pubmed/16808927
15. https://www.ncbi.nlm.nih.gov/pubmed/25642989
16. https://www.ncbi.nlm.nih.gov/pubmed/29206653
17. https://www.ncbi.nlm.nih.gov/pubmed/23440785
18. https://www.ncbi.nlm.nih.gov/pubmed/21900866
19. https://www.ncbi.nlm.nih.gov/pubmed/17828490
20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3698174/
21. https://www.ncbi.nlm.nih.gov/pubmed/19678774
22. https://www.ncbi.nlm.nih.gov/pubmed/18274887

Further sources

1. Hori T, Ridge RW, Tulecke W, Del Tredici P, Trémouillaux-Guiller J, Tobe H Ginkgo biloba, a global treasure - from biology to medicine The Botanical Society of Japan; Springer -Verlag Tokyo, 1997
2. Michel PF Ginkgo biloba, l'arbre qui a vaincu le temps World Wide Fund for Nature/Kiron, éditions du Félin, nov.1999.
3. Van Beek T. Ginkgo Biloba. part 12 in the series Medical and Aromatic Plants - Industrial Profiles, Harwood Academic Publ., Amsterdam, 2000.
4. Schmid M, Schmoll H . Ginkgo, Ur-Baum und Arzneipflanze, Mythos, Dichtung und Kunst S. Hirzel Verlag, Stuttgart-Leipzig, 2001
5. Retallack GJ. A 300-million-year record of atmospheric carbon dioxide from fossil plant cuticles. Nature 411, 287-290, 2001
6. Zhou Z, Zheng S. The missing link in Ginkgo evolution. Nature 423, 821-822, 2003