General information about Ginkgo Biloba
Ginkgo, one of the oldest living tree species in the world (some trees in China are over 2,500 years old), has a long history in traditional Chinese medicine. Members of the royal court received ginkgo nuts for senility. Other historically documented uses of ginkgo are for asthma, bronchitis, and kidney and bladder diseases. 1
Today, ginkgo leaf extract is promoted as a dietary supplement for many conditions, including anxiety, allergies, dementia, eye problems, peripheral artery disease (when plaque buildup narrows the blood vessels that carry blood to the head, organs, and limbs), tinnitus, and other health problems.
Active ingredients in Ginkgo Biloba
Ginkgo biloba has two main active ingredients in different concentrations: terpene lactones (which mostly include ginkgolides and diterpenes) and ginkgo flavone glycosides (which mostly contain ginkethin, bilobethin and sciadopizisin). Most of the studies that investigated the effect of ginkgo biloba used the standardized ginkgo biloba extract (EGb761), which was developed by a German pharmaceutical company in 1964. Flavonoids include quercetin, rutin, kaempferol and isoramnetin. Lactones include ginkgolide A, ginkgolide B, ginkgolide C, bilobalide, and ginggotoxin, lactone, which is structurally related to pyridoxine.
Numerous pharmacological studies have suggested that it is the terpene trilactones and flavonoids in ginkgo that are responsible for the main pharmacological effects of the extract.
Benefits of ginkgo biloba for health
Ginkgo biloba can provide a number of health benefits, including improving cognitive function, supporting blood circulation, relieving leg and joint pain, and more. Traditional uses are wide-ranging, but not all have been confirmed by research, so we will take a detailed look at those for which scientific data are available.
Most of the positive effects of ginkgo are due to high levels of flavonoids and terpenoids, compounds known for their strong antioxidant effects. Antioxidants fight or neutralize the harmful effects of free radicals. Many of the purported benefits of taking ginkgo have been linked to these antioxidant effects.
Improving memory in dementia and Alzheimer's
- Improved thinking and memory
- Better social behavior
- Better ability to perform daily tasks
Another study published in JAMA similarly concluded that EGb 761 is safe to use and effective in stabilizing and possibly improving the cognitive and social functioning of dementia patients over a period of 6 and 12 months. 3
Another study, published in January 2017 in the Journal of Ethnopharmacology, analyzed 12 systematic reviews and concluded that ginkgo has potentially beneficial effects for people with dementia when taken for at least five months. Another systematic review of nine studies found that ginkgo was associated with a delayed decline in cognition, function, and behavior in people with dementia. 4
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 clear ability to increase blood flow to different parts of the body may be the source of its purported benefits for the heart.
Some research suggests that ginkgo can have a positive impact on the symptoms of cardiovascular disease. A study published in December 2017 in the journal Stroke and Vascular Neurology looked at 348 people in China with onset of acute ischemic stroke. About half of the participants adhered to a treatment plan with daily ginkgo and aspirin, while those in the other group received only aspirin. After six months, the researchers found that the group taking aspirin in combination with ginkgo did better, and had reduced cognitive and neurological impairment without increasing the incidence of vascular events. 5
Ginkgo for depression and anxiety
Little research suggests that ginkgo may play a role in the treatment of psychiatric disorders, including depression and anxiety. A study published in September 2018 in the journal Medicine concluded that ginkgo, as an adjunct treatment to a selective serotonin reuptake inhibitor, may help improve depressive symptoms and cognitive function. 7
Anticancer effects of biflavonoids in Ginkgo Biloba
Previous studies have shown that both G. biloba leaf extract and exocarp extract (GBEE) possess inhibitory effects on various cancer cells. Some monomeric compounds have also been reported to have antiproliferative activity on a variety of cancer cells, including ginkkolic acid, ginkgolide B and several bioflavonoids.
A newly discovered biflavonoid — amentoflavone 7′′-O-β-d-glucopyranoside — and four known biflavonoids were isolated and identified from male ginkgo flowers by a team of scientists in 2019. Bilobethin and isoginketin are the flavonoids that show better antiproliferative activity on different lines of cancer. 8
Other potential benefits of ginkgo with less evidence
- May support vision and eye health Very few studies have examined how ginkgo is related to vision and eye health. However, the early results are promising. There have been studies in people with glaucoma and age-related macular degeneration, in which after taking ginkgo there is an improvement in vision. More human studies are needed.
- Can relieve headaches and migraines - In traditional Chinese medicine, ginkgo is a very popular remedy for headaches and migraines. There is very little research on ginkgo's ability to treat headaches. However, depending on the underlying cause of the headache, ginkgo can help.
- May improve symptoms of asthma and COPD Some research suggests that ginkgo can improve symptoms of asthma and other inflammatory respiratory diseases such as COPD. This is due to the anti-inflammatory compounds in ginkgo, which can allow a decrease in airway inflammation and an increase in lung capacity.
Are there any contraindications to the use of ginkgo?
Ginkgo biloba supplements are generally considered safe when taken in moderation. Side effects of ginkgo can include headache, upset stomach, dizziness, allergic skin reactions. Ginkgo seeds should not be consumed as they can be poisonous.