Ginkgo biloba

Ginkgo is the oldest known living species of tree on the earth, dating back over 200 million years. Ginkgo trees can grow to over 100 feet and live up to 1,000 years. The Ginkgo biloba tree we know today probably originated in Asia and was first cultivated in China as a sacred tree.[1] The nut of the ginkgo tree has long been used in Traditional Chinese Medicine, but the leaves didn’t come into common use until Western herbalists started using them in the 20th century. Today ginkgo leaf is one of the most used herbs in the world, consistently making the list of top selling herbs in the US, Europe and Canada.[2] In several European countries the standardized[*] extract of ginkgo is approved as a medicine primarily used to treat memory loss and dementia associated with aging.[3]

Ginkgo is rich in many compounds that have been researched for their beneficial effects on the body.  One of the main actions these compounds exert on the body is to support healthy blood flow and circulation, mainly by blocking platelet activating factors (PAF) from their receptors on cells. PAF plays many roles in the body including causing blood platelets to aggregate, increasing inflammation, constricting the airways and reducing blood flow throughout the body.[4] Ginkgo is believed to block the effects of PAF. Ginkgo also contains many bioflavonoids that act as antioxidants to protect the brain, central nervous system, the retinas, and the cardiovascular system.[5]

Brain Function

Ginkgo seems to be especially well suited to the elderly and in particular for improving circulation to the brain. In elderly patients this improved circulation may improve memory and concentration, absentmindedness, confusion, depression and anxiety.[6] In one animal study, ginkgo increased the formation of new brain cells and inhibited behaviors associated with the formation of beta-amyloid plaques (the abnormal protein clumps found in the brains of Alzheimer’s patients).[7],[8] Many human trials have also shown benefits for brain function.[9],[10] One trial, using 240 milligrams of ginkgo daily for 24 weeks, resulted in significant improvements in cognition, functional measures and quality of life in patients with mild to moderate dementia.[11]

Eye Protection

Many conditions that affect the eyes as we age, such as cataracts, glaucoma, and age-related macular degeneration, benefit from substances that offer anti-oxidant protection while also helping to modulate inflammation and improve blood flow to the eyes. Ginkgo extract offers these advantages, and in several small human studies, ginkgo extract has been shown to improve visual acuity in people suffering from age-related macular degeneration.[12],[13],[14] Ginkgo also appears to improve blood flow to the eyes in those with glaucoma.[15],[16]

Circulatory Benefits

Ginkgo is often recommended for conditions in which impaired circulation is an underlying issue. It appears to benefit the flow of blood through the coronary arteries and improve the relaxation capacity of blood vessels[17],[18] as well as improve circulation to the small capillaries of the outer extremities.[19] Ginkgo may improve dizziness[20],[21], support healthy blood flow to the brain in people who suffer from headaches[22],[23], and improve peripheral circulation in those with vascular disease.[24]

Using Ginkgo biloba

The German Commission E (the scientific board that oversees herbal products in Germany) recommends 120-240 milligrams a day of dry extract in two or three divided doses.[25] It should be noted that the majority of studies using ginkgo extract use one that has been standardized to contain 24 percent ginkgo flavone glycosides and 6 percent terpene lactones. The benefits of ginkgo take time to build in the system and, although results may be seen as early as 8-12 weeks, in some cases it may take six months to a year of regular use for the full benefits to be evident.[26] Ginkgo has a Class 1 safety rating from the American Herbal Products Association, and side effects in studies are rare.[27] Possible mild side effects include upset stomach, mild headache, or allergic skin reactions, all of which tend to resolve themselves after a couple of days.[28] As always, caution should be used when starting any new herb, nutrient, or medication, especially if you are already taking other supplements or medications.


References

[*] Because the quality and potency of an herb is dependent on variables in season, soil, weather,  growing location and post-harvest handling, some companies choose to standardize their herbal products in an attempt to deliver a consistent product every time.  Standardization in botanical extracts refers to delivering a consistent, measurable amount of a recognized plant constituent, often one believed to be an active ingredient.

[1] Brown DJ. Herbal Prescriptions for Health & Healing. Twin Lakes, WI: Lotus Press; 2000.

[2] IARC Monograph on the Carinogenic Risks to Humans. IACR Monographs. 2002;  Volume 82

[3] Dipper C. Scientific review of ginkgo finds promising evidence in improving memory in older patients with dementia [NEWS RELEASE]. American Botanical Council. December 9, 2002.

[4] Venable ME, Zimmerman GA, McIntyre TM, Prescott SM. Platelet-activating factor: a phospholipid autocoid with diverse actions. Journal of Lipid Research. 1993;34: 691-702.

[5] Brown DJ. Herbal Prescriptions for Health & Healing. Twin Lakes, WI: Lotus Press; 2000.

[6] Hoffmann D. Medical Herbalism: The Science and Practice of Herbal Medicine. Rochester, VT: Healing Arts Press; 2003.

[7] Wu Y, Wu Z, Butko P, et al. Amyloid-β-induced pathological behaviors are suppressed by Ginkgo biloba extract EGb 761 and ginkgolides in transgenic Caenorhabditis elegan. J Neurosci. 2006;26(50):13102-13.

[8] n.a. Ginkgo and Alzheimer’s Disease Prevention. Herbal Gram. 2012; 9(11).

[9] Rainer M, Mucke H, Schlaefke S. Ginkgo biloba extract EGb 761 in the treatment of dementia: a pharmocoeconomic analysis of the Austrian setting. Wien Klin Wochenschr. 2013;125(1-2):8-15.

[10] Lautenschlager NT, Ihl R, Mϋller WE. Ginkgo biloba extract EGb 761® in the context of current developments in the diagnosis and treatment of age-related cognitive decline and Alzheimer’s disease: a research perspective. Int Psychogeriatr. 2012;24 Suppl 1:S46-50.

[11] Herrschaft H, Nacu A, Likhachev S, Sholomov I, Hoerr R, Schlaefke S. Ginkgo biloba extract EGb 761® in dementia with neuropychiatric features: a randomized, placebo-controlled trial to confirm the efficacy and safety of a daily dose of 240 mg. J Psychiatr Res. 2012;46(6):716-23.

[12] Fies P, Dienel A. Ginkgo extract in impaired vision—treatment with special extract EGb 761® of impaired vision due to dry senile macular degeneration [article in German]. Wien Med Wochenschr. 2002;152(15-16):423-6.

[13] Lebuisson DA, Leroy L, Rigal G. Treatment of senile macular degeneration with Ginkgo biloba extract. A preliminary double-blind drug vs. placebo study [article in French]. Presse Med. 1986;15(31):1556-8.

[14] Dubey AK, Shankar PR, Upadhyaya D, Deshpande VY. Ginkgo biloba—an appraisal. Kathmandu Univ Med J (KUMJ). 2004;2(3):225-9.

[15] Park JW, Kwon JH, Chung WS, Kim CY, Seong GJ. Short-term effects of Ginkgo biloba extract on peripapillary retinal blood flow in normal tension glaucoma. Korean J Ophthalmol. 2011;25(5):323-8.

[16] Cybulska-Heinrich AK, Mozaffarieh M, Flammer J. Ginkgo biloba: an adjuvant therapy for progressive normal and high tension glaucoma. Mol Vis. 2012;18:390-402.

[17] Wu YZ, Li SQ, Zu XG, Du J, Wang FF. Ginkgo biloba extract improves coronary artery circulation in patients with coronary artery disease: contribution of plasma nitric oxide and endothelin-1. Phytotherapy Res. 2008;22(6):734-9.

[18] Wu Y, Li S, Cui W, Zu X, Du J, Wang F. Ginkgo biloba extract improves coronary blood flow in healthy elderly adults: role o f endothelium-dependent vasodilation. Phytomedicine. 2008;15(3):164-9.

[19] Jung F, Mrowietz C, Kiesewetter H, Wenzel E. Effect of Ginkgo biloba on fluidity of blood and peripheral microcirculation in volunteers. Arzneimittelforschung. 1990; 40(5):589-93.

[20] Cesarani A, Meloni F, Alpini D, Barozzi S, Verderio L, Boscani PF. Ginkgo biloba (EGb 761) in the treatment of equilibrium disorders. Adv Ther. 1998;15(5):291-304.

[21] Haguenauer JP, Cantenot F, Koskas H, Pierart H. Treatment of equilibrium disorders with Ginkgo biloba extrat. A multicenter double-blink drug vs. placebo study [article in French]. Presse Med. 1986;15(31):1569-72.

[22] Usai S, Grazzi L, Andrasik F, Bussone G. An innovative approach for migraine prevention in young age: a preliminary study. Neurol Sci. 2010;31 Suppl 1:S181-3.

[23] Usai S, Grazzi L, Bussone G. Ginkgolide B as migraine preventive treatment in young age: results at 1-year follow-up. Neurol Sci. 2011:32 Suppl 1:S197-9.

[24] Blumenthal M. The ABC Clinical Guide to Herbs. Austin, TX: American Botanical Council; 2003.

[25] Hoffmann D. Medical Herbalism: The Science and Practice of Herbal Medicine. Rochester, VT: Healing Arts Press; 2003.

[26] Blumenthal M. The ABC Clinical Guide to Herbs. Austin, TX: American Botanical Council; 2003.

[27] Blumenthal M. The ABC Clinical Guide to Herbs. Austin, TX: American Botanical Council; 2003.

[28] Brown DJ. Herbal Prescriptions for Health & Healing. Twin Lakes, WI: Lotus Press; 2000.