DATE: Wednesday, October 22, 1997           TAG: 9710220474

SECTION: FRONT                   PAGE: A17  EDITION: FINAL 

SOURCE: ASSOCIATED PRESS 

DATELINE: WASHINGTON                        LENGTH:   58 lines

EXTRACT OF GINKGO PLANT SEEMS TO SLOW ALZHEIMER'S

Ginkgo biloba extract, a herbal medicine used for thousands of years by the Chinese, has been shown to slow the progression of Alzheimer's disease slightly in some patients, researchers report.

In a study to be published today in the Journal of the American Medical Association, researchers say about a third of the dementia patients treated with ginkgo extract showed some improvement after 52 weeks when compared with a similar group of patients who took a placebo.

Dr. Pierre L. LeBars of the New York Institute for Medical Research, lead author of the study, said benefits from the treatment were ``modest'' and were apparent only after about six months of taking the extract.

``The study is the source of more questions than answers,'' said LeBars. He said the effects of ginkgo on the brain are not understood but may be related to antioxidants, compounds that neutralize a destructive form of oxygen.

Zavern Khachaturian of the Alzheimer's Association said the study of ginkgo ``shows something is working a little bit for some people,'' but that more studies are needed ``before we can begin to draw any conclusions'' about use of the plant extract for Alzheimer's patients.

LeBars, who presented the study at an AMA conference Tuesday, said the ginkgo extract used in the study was a highly refined compound produced in Europe from the leaves, nuts and branches of the ginkgo biloba tree.

He said it differs from the ginkgo extract commonly available in health food stores in the United States.

A total of 327 dementia patients were initially enrolled in the study, but only 137 were included in the final results. The others were excluded or dropped out for various reasons, including death.

All of the patients had dementia, a progressive mental decline, with 251 patients diagnosed with Alzheimer's. The rest had suffered strokes. At the start, all of the patients were evaluated using standard tests measuring reasoning, memory and behavior.

The patients were divided, with about half taking the ginkgo extract and half taking a sugar pill. Neither patients nor their caregivers knew who got what dose.

At the end of 52 weeks, the study found that 27 percent of the patients taking ginkgo achieved a four-point improvement on the Alzheimer's Disease Assessment Scale, one of the standard tests. About 14 percent of the placebo patients showed a similar improvement.

On a test based on the evaluation of caregivers, 37 percent of the ginkgo patients were considered improved, as opposed to 23 percent of those on placebo.

No difference was seen in a third test.

The ginkgo extract, called EGb 761, has been approved for medical use in Germany, but not in the United States. LeBars said it is uncertain if the herb sold as a diet supplement in this country would have the same effect as EGb 761.

Some forms of ginkgo have been a part of traditional medicine for thousands of years in China, where the herb is said to be beneficial for a variety of ailments, from arthritis to emotional depression. Some modern studies also have linked ginkgo to correcting impotence in some patients.

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