In Europe, the extract produced from the leaves of this tree is available in the form of two prescription medicines. Millions of prescriptions are written every year for these Gingko preparations putting them into the top 3 pharmaceuticals in both Germany and France.
Most prescriptions are written for elderly patients to help stimulate circulation of blood to the brain and hence to improve mental performance. However, clinical studies are proving that this is only one health enhancing attribute of this amazing tree. A summary of the areas in which Ginkgo extracts have been used follows.
In a randomised, double blind, crossover study, a daily dose of 120mg-160mg of Ginkgo Biloba extract was shown to improve mental performance of elderly patients and to increase their vigilance and concentration. In another study the reaction time of healthy young women performing a memory test was improved when they took Ginkgo Biloba. The authors of the study concluded by saying “These results differentiate Ginkgo Biloba extract from sedative and stimulant drugs and suggest a specific effect on memory processes.”
In another open trial involving 112 geriatric patients with chronic cerebral insufficiency, Ginkgo Biloba extract appeared to improve short-term memory loss, vertigo, headache, tinnitus, lack of vigilance and mood disturbance.
It has been shown that substances in Ginkgo Biloba extract are able to block the Platelet Activating Factor (PAF) which is produced by the body in response to allergens that are inhaled. PAF activates certain immune cells which then secrete chemicals that cause inflammation. It is believed that in asthma sufferers, either too much PAF is produced or the PAF activates too many immune cells, which leads to inflammation of the lungs and thus to the symptoms of asthma. In a small trial, a standardised mixture of ginkgolides given to asthmatic patients was found to significantly inhibit the response to the allergens that they inhaled.
This work is in its very early stages and the use of Ginkgo Biloba for asthma has yet to be clinically proven. However, many asthma specialists believe PAF blockers will be the next major group of drugs for this condition.
Peripheral Arterial Insufficiency
This term describes the restriction of blood flow to the legs which tends to become increasingly common with age. It is often speeded up by smoking and eating foods that are high in processed saturated fats. The restriction of blood flow to the legs causes pain when walking – a condition referred to as intermittent claudication. However, this condition can be improved by removing the risk factors and by improving the diet to include plenty of fresh fruit and vegetables. Ginkgo Biloba has also been shown to be beneficial. In one of the larger studies, of 79 patients diagnosed as having diseased arteries in their legs, half were given 40mg of Ginkgo extract 3 times per day, the other half a dummy pill. The Ginkgo group showed a highly significant increase in their ability to walk for distance without pain and cramping. Also numbness of the extremities was reduced.