Ginkgo (Ginkgo biloba L.)
Ginkgo, the maidenhair tree, is a native of Central China whose leaves are widely used in herbal medicine to treat conditions associated with poor circulation. It is the sole survivor of a primitive order of plants dating from 200 million years ago. The earliest record of the medicinal use of Ginkgo is in ‘Chen Houng Pen T’sao’ published in 2800 BC. The leaves are rich in bioflavonoids, amino acids, terpenoids and proanthocyanidins.
Ginkgo is one of the most heavily researched herbal medicines and clinical trials thus far have been encouraging. Clinical trials with small numbers of patients have demonstrated that ginkgo leaf is effective in the treatment of arterial insufficiency, particularly in the lower limbs and brain. In people suffering from intermittent claudication, significant improvements in pain-free walking time and maximum walking distance have been achieved. Recent research indicates that the extract GBE from the yellow autumn leaves contains a vitamin that strengthens blood vessels, reduces the production of tissue-damaging free radicals and improves cellular energy. The bioflavonoids protect and maintain the integrity of capillary walls, inhibit lipid peroxidation within cell membranes, stabilise the cell membranes involved in the blood-brain barrier, destroy free radicals and inactivate their formation. Ginkgo has a demonstrable effect on the venous system too and is used to treat conditions such as varicose veins.
Elderly patients with chronic cerebral insufficiency who took part in a clinical trial demonstrated a significant regression of major symptoms including vertigo, tinnitus, headache, short-term memory, vigilance and mood changes. Ginkgo has also been shown to improve the utilisation of glucose within the brain. It improves the transmission of nerve impulses and increases alertness by increasing the brain’s alpha wave rhythms and decreasing theta rhythms.
Ginkgo has been shown to improve eyesight in senile macular degeneration and to neutralise the effects of oxygen free radicals produced in the eyes. Other trials have suggested that ginkgo could help protect against altitude sickness, and improvements in allergic responses such as asthma have been observed.
Ginkgo leaf is thought to alleviate male impotence where the underlying cause is impaired blood circulation to erectile tissue; initial signs of improvement were seen to commence after 8 weeks of Ginkgo biloba supplementation and, after 6 months, 50% of patients had regained potency.
The recommended dose of the dried leaf is 400mg twice a day. People taking blood-thinning medication such as Warfarin should take the advice of a qualified professional since, theoretically at least, ginkgo could induce spontaneous bleeding although no such interactions have been observed in controlled studies. No interactions with medication such as cardiac glycosides and antidiabetic drugs have been noted in clinical trials with the leaf extract. Mild adverse reactions such as gastrointestinal upset and headache have been reported.
NB: The above information is for guidance only, and is not intended to take the place of diagnosis and treatment by a qualified practitioner. Some herbs may interact adversely with other medication, so make sure that your health professional is aware of everything you are taking.