GinkgoSense?, is derived from the leaves of the ginkgo biloba tree, one of the oldest living tree species. The tree has survived for so long because it is resistant to infection and resilient against parasites and pollution. In fact, ginkgo trees are so hardy that a solitary ginkgo was the only tree to survive the atomic blast in Hiroshima, Japan.

Ginkgo's medical use can be traced to ancient China, where the population used the dried herb to treat poor circulation, memory loss, and general mental deterioration. The world's first great herbalist, the Chinese emperor Shen Nung, called ginkgo "good for the heart and lungs," and it appears he was on the right track.

Benefits

Ginkgo appears to stimulate circulation by making blood vessels and red blood cells more flexible, thus making it easier for blood to wind its way through the body. This increased circulation may also be one reason why ginkgo has shown positive results in vascular conditions. This includes cerebral circulation-transporting all-important glucose and oxygen to the brain. Subnormal cerebral circulation may affect memory and other cognitive functions. Trials in Europe have shown that ginkgo is effective in enhancing memory and concentration, and in improving circulation.

One of the first 1990s studies to gain widespread attention on ginkgo biloba extract (GBE) and memory is "Ginkgo Biloba for Cerebral Insufficiency," by Jos Kleijnen and Paul Knipschild. Published in the British Journal of Clinical Pharmacology (October 1992), this study was actually a critical review of previous studies and intended to establish whether there is evidence of GBE's usefulness in cerebral insufficiency.

Cerebral insufficiency is a general term for a collection of symptoms that include difficulties in concentration and memory, absent-mindedness, confusion, lack of energy, tiredness, depressive mood, anxiety, dizziness, tinnitus, and headache. These symptoms have been associated with impaired cerebral (brain) circulation and are sometimes thought to be early signs of dementia.

The authors determined that at that time there were eight well-performed trials out of a total of 40, and in their abstract state, "Positive results have been reported for ginkgo biloba extracts in the treatment of cerebral insufficiency. The clinical evidence is similar to that of a registered product that is prescribed for the same indication. However, further studies should be conducted for a more detailed assessment of the efficacy."

A 1994 study (Phytomedicine 1, 9-16) shows that regular administration of GBE has a positive influence on subjects with cerebral insufficiency. The study focused on "long-term and short-term memory, concentration power, maximum stress, mental flexibility, family problems, and general satisfaction of the patient with his or her life." Positive effects were noted after six weeks of use. A 1995 report in the Psychopharmacol Bulletin (31, no. 1 (1995): 147-58) reports on using GBE in dementia. It notes that GBE is among the most popular over-the-counter medicines in Europe, that the European medical community has recognized it "as an effective compound in the treatment of cerebral insufficiency," and that it has earned the "approval of the German Federal Health Agency for use in the treatment of dementia."

In October 1997 came the "groundbreaking" study on GBE-groundbreaking not because of new information but because it was published in the prestigious and mainstream Journal of the American Medical Association (JAMA). JAMA reported that GBE may be beneficial in the treatment of Alzheimer's disease.

This was followed up by a 1998 meta-analysis (an analysis of all studies available on a subject) that attempted to identify all English- and non-English-language research in which GBE was given to subjects with dementia or cognitive impairment. In the abstract to this study, the authors note that ". there is a small but significant effect of three- to six-month treatment with 120 to 240 mg of G. biloba extract on objective measures of cognitive function in Alzheimer's disease." (Archives of Neurology 55, no. 11 (November 1998): 1409-15.)

Ginkgo by the body

The brain: Blood flow in the brain decreases as we age. This means less food and oxygen for brain cells. European studies show that ginkgo increases blood flow in the brain, ensuring that the brain receives the food and oxygen it needs to function.

The heart: Ginkgo also improves blood flow to the heart. Because it inhibits PAF, ginkgo may reduce the possibility of blood clots forming in coronary arteries.

The legs: Ginkgo's antioxidant capabilities may help reduce the transformation of cholesterol to plaque and the "next step" of narrowed and hardened arteries. This could have a hand in preventing intermittent claudication (lameness), pain, and cramping.

The eyes: Blood flow to the retina decreases with age. This means that the eyes may not get the nutrients they need. Retinal deterioration may lead to macular degeneration, a leading cause of adult blindness. Ginkgo's antioxidant and blood-circulating properties could help.

The ears: Again due to decreased blood flow with age, the nerves of the inner ear do not get sufficient blood. This could result in cochlear deafness, a leading cause of age-related hearing loss.

Suggested Reading

• Kleijnen, Jos, and Paul Knipschild. "Ginkgo biloba for cerebral insufficiency." British Journal of Clinical Pharmacology 34 (1992): 352-58.

• Murray, Frank. Ginkgo Biloba. New Canaan, CT: Keats Publishing, Inc., 1996.