Food for Thought – Ginkgo biloba

Ginkgo biloba is an example of traditional herbal wisdom, mainly derived from the doctrine of signatures, empirical evidence and generations of use. It has been far ahead of the scientific community in applying Ginkgo for healing benefit.

One of the tenets of herbalism is the 'Doctrine of Signatures.' It states that if we are able to listen and learn from the plant itself by visiting its habitat, recognizing its relationships with other organisms and by appreciating its sensual characteristics such as color, shape, smell, taste and feel, we will be pointed to indications for its use.

Ginkgo is the oldest living tree species and can be traced back more than 200 million years. Once common in North America and Europe, the Ginkgo was almost destroyed in the Ice Age in all regions of the world except China where it has been cultivated as a sacred tree. At present, Ginkgo has been planted throughout North America, mainly as an ornamental tree. Ginkgo has one of the most distinctive and interesting leaf shapes. It is a fan-shaped leaf, divided into two lobes, appropriately named biloba. It seems rather serendipitous that the Ginkgo leaf should closely resemble the human brain.

The medicinal use of Ginkgo has been traced back to the oldest Chinese Materia Medica in 2800 BC. The Ginkgo nut was used to expel mucus from the bronchioles and lungs and to inhibit a cough. However, the nut can be toxic in large amounts.

Today, when people speak of Ginkgo, they are speaking of the Ginkgo LEAF extract. In fact, Ginkgo leaf extracts are now among the leading prescription medicines in Germany and France, where they account for 1% and 1.5% respectively, of total prescription sales. In 1989, more than 100,000 physicians worldwide wrote more than 10 million prescriptions for Ginkgo biloba extracts (1).

Ginkgo is not an herb of youth. Rather, it chooses to exert its activity on the circulation, one of the systems most often affected by the aging process. While there are studies of young people benefiting from Ginkgo (2, 7), most studies have focused on the use of Ginkgo in conditions such as insufficient blood flow of the brain resulting in poor memory, depression or dementia, and in cases of peripheral vascular insufficiency such as intermittent claudication (3). These situations are most common in an aging population.

These effects have been attributed to the presence of flavone glycosides within the Ginkgo leaf. Most Ginkgo extracts are standardized to contain 24% of these constituents; the use of these extracts is supported in over 300 clinical and experimental studies. Ginkgo tinctures are also effective if careful attention is placed on the quality of tincture obtained.

Ginkgo and the Brain

Research has shown Ginkgo to have numerous effects on the brain.

1. Ginkgo normalizes circulation by producing tonic effects on the blood vessels. Ginkgo causes the blood vessels to dilate, thereby increasing circulation and delivery of oxygen and glucose to the brain cells. Ginkgo has been shown to increase the circulation in the brain in areas most affected by clots (5).
   
   
2. Metabolic reactions produce free radicals that are very reactive by-products and will attack cellular membranes. Ginkgo works as an anti-oxidant to protect the membranes of the brain cells from damage (5).
   
   
3. Nerve cell transmission is dependent on the transport of potassium into (and sodium out of) the cell. Ginkgo increases the rate at which this happens; thus information is transmitted faster at the nerve cell level (4).
   
   
4. Ginkgo has an anti-platelet effect, which decreases the chance of blood clot formation in all areas of the body (6).

Ginkgo is extremely safe. Side effects are uncommon if taken appropriately. There has been concern raised regarding drug/herb interactions with Ginkgo, and blood thinning medications because of its anti-platelet effects. Prudence in taking this herb should be indicated in this situation.

Ginkgo has many benefits so to call it the "memory" or "brain" herb does not do it justice. It has been used to help with impotence, ringing in the ears (tinnitus), multiple sclerosis, neuralgia and neuropathy. Recent research has shown it to be effective in delaying mental deterioration in the early stages of Alzheimer's disease. The essence of Ginkgo is "nourishment." While each of our cells gain nourishment through improved circulation, so too do our minds gain nourishment from the many centuries of wisdom Ginkgo brings with it. It truly is "food for thought."

References

1. Murray, Michael T. 1995. The Healing Power of Herbs. Prima Publishing, Inc. p. 145.
   
   
2. Hindmarch, I. and Sughan, A. 1984. The Psychopharmacological Effects of Ginkgo Biloba Extract in Normal Healthy Volunteers. Int J Clin Pharmacol Res 4, 89-93.
   
   
3. Peters, H, Kieser M, Holscher U. 1998. Demonstration of the Efficacy of Ginkgo biloba Special Extract on Intermittent Claudication: a Placebo-Controlled, Double-Blind Multi-center Trial. Vasa: 27(2): 106-110.
   
   
4. Gessner, B., Boelp, A., and Klasser, M. 1985. Study of the long-term action of Ginkgo biloba extract on vigilance and mental performance as determined by means of quantitative pharmaco-EEG and psychometric measurements. Arzneimittel-Forsch 35, 1459-1465, 1985.
   
   
5. DeFeudis FV (editor). 1991. Ginkgo biloba Extract: Pharmacological Activities and Clinical Applications, Elsevier, Paris, 1991.
   
   
6. Kleijnen J and Knipschild P, 1991. Ginkgo biloba. Lancet 340: 136-9
   
   
7. Tamborini, A; Taurelle R, 1993. Value of Standardized Ginkgo biloba Extract in the Management of Congestive Symptoms of Premenstrual Syndrome. Rev. Fr Gynecol Obstet (France) 88: 447-457.