Ginkgo biloba trees, also known as maidenhair trees or kew, are members of a plant family that can be traced back 150 million years. Millions of years ago, ginkgo trees grew wild in the Americas, Europe, and Asia. Now, their ancestors survive wild only in Southeast China – the rest growing currently are cultivated by humans. You may have noticed them in parks or lining streets, with their distinctive, silver, lobed leaves that seem to sparkle in the wind.
Components of the ginkgo tree have been used by practitioners of Traditional Chinese Medicine (TCM) since around 2800 BC. TCM practitioners have used ginkgo leaves for brain disorders, memory loss, problems with circulation, and respiratory diseases. Practitioners also use ginkgo nuts to alleviate coughs, fever, diarrhea, and heal skin diseases.
Science is now taking a look at the effectiveness of ginkgo leaf extract on various conditions, particularly its effects on improving cognition. Germany, in particular, has looked into supporting cognition with ginkgo extract, and in the United States, ginkgo extracts are one of the more popular supplements sold.
In this article, we’ll look at what science has to say about the effectiveness of ginkgo supplements for various conditions, especially brain health.
Bioactive Components of Ginkgo
The primary, bioactive components of ginkgo are terpenoids and flavonoids. The terpenoids present in ginkgo are ginkgolides A, B, and C and bilobalide. The primary flavonoids are quercetin, kaempferol, meletin, and isorhamnetin. Ginkgo also contains some phytochemicals that can produce allergic responses and other adverse effects, called ginkgolic acids. However, in high-quality extracts, these are present at less than 5 parts per million.
Health Qualities of Ginkgo
Ginkgo is considered to have antioxidant and anti-inflammatory properties. It is also said to improve blood flow and circulation, both within the brain and peripherally, which may account for its effect on cognition and memory. Dr. Daniel G. Amen, MD, who has written numerous books on brain health and has looked at the brain scans of many people over his career, writes in his book The End of Mental Illness that the best looking brain scans he sees in his practice are of people who take ginkgo supplements.
Two recent scientific reviews gathered data from numerous studies on ginkgo done over the years. One review looked at ginkgo’s effect on dementia, and the other at its effectiveness for tinnitus. Here’s what the authors found:
1. Ginkgo May Help with Neurodegeneration.
A 2010 review assessed the effects of a German standardized extract of ginkgo (EGb761) on patients with Alzheimer’s disease (AD), as well as patients suffering from vascular and mixed dementia. The study compared nine different trials that looked at the change in cognitive outcomes using the extract.
The review’s authors found a statistically significant advantage in improving cognition for all of the patients who were supplemented with ginkgo extract. Of note was that patients with AD also improved their ability to participate in daily activities. Side effects were minimal and equal to those of the placebo groups. To better understand the use of ginkgo in neurodegenerative conditions, researchers suggested that a major, multicenter study should be the next step toward better understanding this ancient herb.
2. Ginkgo May Lessen Symptoms of Tinnitus.
Tinnitus is a ringing, whistling, or buzzing sound in the ear, sometimes associated with hearing loss. Tinnitus can occur when the cells of the auditory nervous system generate abnormal signals, which are then erroneously translated into sound. Tinnitus can be intermittent or constant and can range from annoying to debilitating, depending on its severity. It often becomes chronic.
A 2011 review compared eight different trials involving a standardized extract of ginkgo (again EGb761) and its effectiveness on tinnitus. In three of the studies, patients listed tinnitus as their primary complaint. In the remaining five, patients had some age-related cognitive decline or dementia, with tinnitus as a secondary symptom.
In all eight studies, positive outcomes for tinnitus were reported with the standardized extract of ginkgo when compared to placebo. The study’s researchers noted that the quality of ginkgo extracts (EGb761) used may have an impact on its results due to its enhanced bioavailability. Additionally, they noted the use of ginkgo extracts for the management of tinnitus is limited.
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Ginkgo can be taken as a tincture, in tablets, or as an extract powder mixed into drinks or made into tea. Take care in choosing your source — all ginkgo extracts are not created equal. Choose a product that is organic, well-researched, and third-party certified for purity and potency. For reference, the German extract EGb761 is standardized to 22–27% flavone glycosides and 5–7% terpene lactones.
Side Effects and Contraindications
Standardized ginkgo extracts of 240mg or lower per day are generally considered safe. However, ginkgo is said to have blood-thinning effects, so anyone taking blood thinners or with a bleeding disorder should be cautious with its use. As always, consult your healthcare provider first before starting any new herb or supplement.
Gingko trees are not only beautiful, but they harbor phytochemicals that may improve symptoms of neurodegeneration and tinnitus. Ginkgo is one of the more popular supplements taken in the US, as we seek to find ways to preserve our memory and brain function for as long as possible. However, take care in choosing a high-quality ginkgo extract, as some of the components of the whole plant may contain allergens. Choose wisely, and your brain may thank you.
Shona Curley lives and works in San Francisco. She is co-owner of the studio Hasti Pilates, and creator of the website www.redkitemeditations.com. Shona teaches meditation, bodywork and movement practices for healing Lyme disease, chronic illness and pain.
Amen DG. The end of mental illness. Carol Stream, Illinois. Tyndale House Foundation: 2020.
Published 2011 Jul 28. doi: 10.2147/NDT.S22793
Weinmann S, Roll S, Schwarzbach C, Vauth C, Willich SN. Effects of Ginkgo biloba in dementia: systematic review and meta-analysis. BMC Geriatr. 2010; 10: 14. Published 2010, March 17. doi: 10.1186/1471-2318-10-14