What is ginkgo?
Ginkgo, scientifically known as Ginkgo biloba, is one of the oldest living tree species in the world. The plant originates from China, but also grows in many other parts of the world, including various parts of North America, Europe and Asia.
Ginkgo trees thrive in temperate climates and can grow over 30 metres tall in some areas.
Ginkgo is rich in numerous bioactive compounds, most of which are contained in its leaves. In particular, ginkgo is rich in the following compounds:
- flavonoids
- Terpenoids (especially the ginkgolides)
- alkylphenols
- lignans
- polysaccharides
Health benefits of ginkgo:
Ginkgo is one of the most researched plants in the world. While the benefits of ginkgo for Alzheimer's disease and dementia have attracted much attention, there are many research studies showing many other potential health benefits of ginkgo.
Many of these studies are clinical trials, which tend to have the highest degree of credibility and applicability. Overall, ginkgo is associated with the following health benefits:
May help with Alzheimer's disease
Numerous clinical research studies have made it relatively clear that ginkgo helps Alzheimer's and dementia patients. This is partly due to the neuroprotective effects of ginkgo, which reduce oxidative stress and inflammation in the brain.
In a randomised clinical trial involving 395 patients aged 50 years and older, those taking 240 mg of ginkgo extract showed significantly fewer symptoms of Alzheimer's and dementia and significant improvements in cognitive function and mental health compared to the control group.
In an observational study, researchers investigated the efficacy of donepezil (a common Alzheimer's/dementia medication) versus ginkgo biloba extract in the treatment of Alzheimer's disease in elderly patients. After 12 months, they found that ginkgo was similar (if not slightly better) than donepezil in terms of improving memory and cognitive function, but had fewer side effects and a better safety profile.
In another clinical trial of 404 patients with either Alzheimer's disease or vascular dementia, patients receiving ginkgo extract showed significant improvements in memory, mood and general functioning in daily life compared to placebo. The level of distress experienced by carers was also significantly lower in the ginkgo group.
A clinical double-blind study on 410 outpatients with mild to moderate dementia also showed very similar results to the above study. In particular, the Ginkgo patients had a significant improvement in Alzheimer's/dementia symptoms, quality of life and cognitive function.
However, not all studies showed positive results. A clinical study of 214 elderly patients found that taking ginkgo did not significantly improve dementia or age-related memory impairment. Furthermore, ginkgo did not significantly improve behaviour or aspects of daily life.
Another clinical study of outpatients with dementia found inconclusive results for the efficacy of ginkgo in the treatment of dementia. However, it was found that patients taking Ginkgo biloba extract (either 120 mg or 240 mg/day) had significantly better cognitive performance and reduced disease severity compared to placebo.
May improve cognitive function
Ginkgo is thought to improve cognitive function in healthy young people.
In one study, 20 healthy volunteers were given either a placebo or either 120 mg, 240 mg or 360 mg of ginkgo extract. The researchers found a dose-dependent improvement in attention span, meaning that higher doses (up to 360 mg) appeared to produce better results. In addition, all doses of ginkgo were associated with significant improvements in memory and cognitive function compared to placebo.
Another clinical trial involving 78 healthy young people found that a low dose (120 mg) of ginkgo led to significant improvements in some aspects of memory, such as working memory and memory quality, but not attention, compared to placebo.
In another clinical trial with 61 healthy participants, Ginkgo biloba extract was associated with significant improvements in working memory, information processing and executive functions compared to the control group.
Finally, in one study, 20 healthy, young volunteers were selected to take ginkgo, Asian ginseng (Panax ginseng), a ginkgo/ginseng combination or a placebo, each separated by a run-out phase.
They found that taking ginkgo alone led to significant improvements in the areas of memory, attention, information processing and mood. The ginkgo/ginseng combination also led to a significant improvement in memory, attention and information processing, but not in mood. So it seems that taking ginkgo alone was just as effective as the combination with ginseng, if not more so.
Can reduce anxiety and depression
In addition to cognitive health, ginkgo may also benefit mental health by reducing anxiety, depression and stress.
In a study of 80 patients suffering from post-stroke depression, it was found that the subjects who received ginkgo along with venlafaxine (a medication for depression and anxiety) were significantly less depressed and coped better with their daily lives than the patients who received venlafaxine alone.
In addition, the patients taking ginkgo along with venlafaxine had higher levels of BDNF (a compound needed for overall brain health) and 5-HT (a compound important for mood and well-being) than the venlafaxine group. Finally, the combination group required lower doses of venlafaxine and had fewer side effects.
In another clinical study of 81 patients with major depression, subjects who received 120 mg of Ginkgo biloba extract in addition to electroconvulsive therapy (ECT) showed greater improvements in cognitive function and less depression compared to ECT alone.
It is also known that dementia is associated with many mental disorders. In a study of over 400 dementia patients with mental symptoms, it was found that treatment with 240 mg ginkgo extract led to a significant reduction in anxiety, apathy, irritability, depression and sleep disturbances compared to the control group.
Another study investigated the effects of ginkgo on anxiety. It involved 107 patients suffering from either generalised anxiety disorder or adjustment disorder with anxious mood. The researchers found that the participants taking ginkgo (either 240 mg or 480 mg) showed significantly less anxiety, tension and aggression compared to the placebo.
Finally, a randomised controlled trial with war refugees found that participants who received treatment with Ginkgo biloba extract in addition to psychoeducation showed significantly less anxiety, stress and mental and physical fatigue compared to psychoeducation alone.
Can support heart health
Various clinical studies have also shown that ginkgo promotes heart health and related factors.
In a clinical study involving 11 people with metabolic syndrome, the additional intake of Ginkgo biloba extract led to a significant reduction in various inflammatory markers such as IL-6 and C-reactive protein. In addition, the Ginkgo patients showed significantly fewer markers for atherosclerosis and plaque formation. All these results indicate a reduction in cardiovascular and mortality risk.
In another study of 8 patients who had undergone coronary bypass surgery, ginkgo treatment was shown to reduce plaque formation and inhibit atherosclerosis (narrowing of the arteries) while improving blood flow, cholesterol and blood lipid profiles. In addition, ginkgo patients had significantly higher levels of superoxide dismutase and other antioxidant enzymes, suggesting further protective effects on heart health.
In a clinical study of 102 patients with acute ischaemic stroke, patients receiving ginkgo extract had significantly reduced severity of stroke symptoms, such as consciousness, speech, physical strength and sensory loss, compared to placebo patients.
In a clinical study of 8 patients undergoing coronary bypass surgery, it was found that treatment with ginkgo led to a significant reduction in plaque formation and atherosclerosis. In addition, ginkgo appeared to increase antioxidant activity and improve blood lipid profiles.
Finally, in a study of 50 hypertension (high blood pressure) patients, it was found that treatment with ginkgo extract resulted in significantly lower total cholesterol and triglyceride levels compared to the control group.
Antidiabetic properties
Research also suggests that ginkgo has an anti-diabetic effect, particularly in people with type 2 diabetes (T2D).
In a placebo-controlled clinical trial in patients with T2D, treatment with a Ginkgo biloba extract resulted in a significant reduction in HbA1C (a marker of blood glucose levels), glucose and insulin levels compared to placebo. In addition, the group treated with ginkgo showed significantly lower values for body mass index (BMI) and visceral fat after 90 days of treatment.
In another study of 60 patients with T2D and 60 patients with metabolic syndrome, supplementation with ginkgo extract was found to significantly reduce BMI, waist circumference and visceral fat while improving glucose and insulin levels, insulin resistance and lipid profiles. Finally, the treatment was associated with a decrease in inflammation and an increase in overall antioxidant capacity.
Another study examined the effects of a combination treatment of Ginkgo biloba and Liuwei Dihuang (a traditional Chinese herbal formula) on individuals with T2D with or without early-stage diabetic nephropathy (a potential kidney complication often associated with T2D). The researchers found that this combination treatment was associated with a significant reduction in urine albumin-to-creatinine levels (a test for kidney damage and impaired function) compared to placebo.
Finally, in a clinical trial of 56 patients with T2D, it was found that treatment with ginkgo tended to result in better glycaemic control compared to green tea (Camellia sinensis) treatment and the placebo group. In addition, ginkgo treatment was associated with a significant improvement in psychological functioning and a reduction in stress compared to the other two groups.
May help with ADHD
A small amount of research also shows that ginkgo helps with attention-deficit/hyperactivity disorder (ADHD).
In a clinical study of 20 children with ADHD, it was found that children who took up to 240 mg of ginkgo extract had significantly fewer ADHD symptoms compared to the control group and that quality of life, attention and task performance improved.
Another clinical study with 60 children showed that treatment with ginkgo extract together with methylphenidate (a common ADHD medication) led to greater improvements in ADHD and attention compared to the placebo group.
Can alleviate tinnitus
Finally, some studies show that ginkgo can relieve tinnitus, especially in older people.
In a randomised clinical trial of tinnitus patients, treatment with ginkgo extract was found to be similarly effective as pentoxifylline (a common tinnitus medication) in reducing loudness, annoyance and overall discomfort/disability. In addition, ginkgo was associated with fewer side effects compared to pentoxifylline.
In another clinical trial, 33 patients were treated with either hearing aids, ginkgo extract or a combination therapy. The researchers found that ginkgo treatment alone or in combination with hearing aids was associated with lower volume and severity of tinnitus.
Safety:
Ginkgo appears to be safe for most people when taken orally in moderate amounts.
Possible side effects of ginkgo include headaches, stomach upset, dizziness, palpitations, constipation and allergic reactions.
Ginkgo can also interact with blood thinners and increase the risk of bleeding. Ginkgo alone increases blood flow and blood thinning, so the risk of bleeding may increase when taken with similarly acting medications.
Pregnancy and breastfeeding:
Pregnant or breastfeeding women should not take ginkgo as it may be unsafe. In particular, ginkgo has antiplatelet properties that can prolong bleeding time during labour. In addition, the effects of ginkgo on the reproductive stages are unclear, so it is usually best to avoid such herbs during pregnancy or breastfeeding.
Dosage:
According to research, ginkgo extract needs to be standardised to have the greatest effect, as raw ginkgo leaves or low concentration leaf extracts have no scientifically proven benefits.
The two most important components of ginkgo are terpene lactones and ginkgo flavone glycosides. In these preparations, the beneficial doses are typically in the range of 120 to 240 mg, although doses of up to 480 mg have been used successfully for some conditions.
How to include ginkgo in your diet:
Ginkgo is most commonly taken in supplement form, either as a tablet, extract or capsule. However, it can also be consumed as a tea.
Research shows that taking a standardised form of ginkgo in tablet, extract or capsule form has the greatest health benefits.
Naming & Taxonomy:
Ginkgo (Ginkgo biloba) belongs to the Ginkgoaceae family. Ginkgo trees can be recognised by their somewhat conical shape with the characteristic two-lobed, fan-shaped leaves.
The leaves are deep green and turn bright yellow in autumn. In addition, the trunk of the ginkgo can often grow up to 100 feet high and eight feet wide.
The ginkgo is one of the oldest living tree species on our planet. Some ginkgo trees can live for hundreds of years, in some cases even up to 3,500 years.
History & traditional use:
Ginkgo has been used as a traditional medicinal plant in China and other parts of the world for over 2,000 years.
Ginkgo leaves have been widely used in traditional Chinese medicine and other cultures to treat blood disorders, improve memory and cognitive abilities, heart problems, lung and respiratory diseases and to improve skin conditions.
In addition, the nuts and seeds of the ginkgo tree have been widely used in China and other parts of the world for culinary purposes, but sometimes also for the medicinal purposes described above.
Conclusion:
Ginkgo is a plant with significant historical medicinal uses for a variety of ailments. It is rich in many different bioactive compounds, and modern research has revealed the many potential benefits of ginkgo, particularly its leaves.
Ginkgo has the potential to protect against Alzheimer's and dementia, improve cognitive function, relieve anxiety and depression, improve heart health, reduce diabetes, alleviate ADHD and reduce tinnitus.
All in all, ginkgo appears to be a safe and beneficial plant to incorporate into your daily routine on a regular basis.