Natural Health Journals

Ginkgo Biloba

WHAT IT IS The ginkgo tree, native to China and now found throughout the world, has been around longer than any other species of tree on the planet, for about 300 million years. You’ve probably seen the ginkgo, with its cloven fan-shaped leaves that turn bright yellow in autumn. Ginkgo leaves have been used as a general tonic in Chinese herbal medicine for thousands of years.

REPORTED EFFECTS While some people describe remarkable improvements in cognition and clear-headedness after taking ginkgo, the herb is also recommended as a way for a normal, healthy person to counteract oxidative stress in the brain, promote circulation in the brain, and slow the aging process. And a couple of recent studies with patients suffering from Alzheimer’s disease and other forms of cognitive impairment have shown that ginkgo can actually reverse some memory impairment and improve cognitive ability.

HOW IT WORKS Ginkgo is known mainly for its ability to improve blood circulation in the body and brain. A number of proponents of ginkgo state that increased cerebral blood flow improves memory and cognition.

THE EVIDENCE A study published in the Journal of the American Medical Association in October 1997 showed that ginkgo biloba extract can help to slow cognitive decline in patients suffering from Alzheimer’s disease. And in 1995, in another placebo-controlled clinical study on Alzheimer’s patients over a three-month period, patients taking ginkgo showed marked improvement in memory and attention span.

On the other hand, there’s some debate on whether increased blood flow to the brain really enhances cognition. Thomas Crook, Ph.D., president and chief executive officer of Psychologix, Inc., a medical and psychological research company in Scottsdale, Arizona, said he’s not convinced that ginkgo has any effect on cognition. In a study sponsored by the National Institutes of Health, Crook and his colleagues “found there is no relationship between oxygen levels in the blood and cognition.”

CAVEATS No side effects have been observed in people using ginkgo over a long period of time. Note that many clinical studies on ginkgo use extremely high concentrated doses of the herb. Dietary supplements you can buy over the counter in the United States usually contain a lower ratio of ginkgo extract, so comparable dosages of these supplements may not produce the same effects.

WHERE TO FIND IT Ginkgo biloba extract is widely available in health foods stores. For a normal, healthy person who wishes to slow or prevent cognitive decline, 90 mg is considered a reasonable daily dose. Patients with significant memory or cognitive impairment may try taking a dose of 120-160 mg daily, divided into three equal doses throughout the day.


COPYRIGHT 1998 Weider Publications
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