Ginkgo may slow memory decline in 'oldest old'

Last Updated: 2008-05-16 13:00:28 -0400 (Reuters Health)

By Joene Hendry

NEW YORK (Reuters Health) - The popular herb ginkgo biloba may help slow memory loss in even the oldest elderly, provided they take the supplement regularly, a small study suggests.

In a study of 118 adults age 85 and older, researchers found that those who were randomly assigned to take ginkgo extract -- and stuck with the regimen -- showed less memory loss over three years.

The findings suggest that "ginkgo biloba supplements may protect against a decline in memory function among individuals 85 years and older," lead researcher Dr. Hiroko Dodge, of Oregon State University in Corvallis, told Reuters Health.

However, she and her colleagues say, any benefit from ginkgo biloba, an extract from a tree native to China, needs to be confirmed by larger prevention studies that are currently underway in the U.S. and Europe.

Researchers also need to establish that ginkgo is safe for elderly adults to use over the long term. In their study, Dodge and her colleagues found that ginkgo users had a higher rate of ischemic strokes, which are caused by blood clots.

Whether this was a side effect of the herb is not clear; in the past, ginkgo has been linked to a higher risk of bleeding, not blood clotting.

Dodge and her colleagues report their findings in the journal Neurology.

The study included 118 men and women who were at least 85 years old and had normal memory function at the outset. All of the participants took a daily multivitamin containing 40 units of vitamin E. Half were also directed to take a total of 240 milligrams of ginkgo biloba daily, while the rest were given a placebo for comparison.

Overall, the researchers found, there was no difference between the two groups in memory decline over three years. But when they zeroed in on participants who had adhered to their treatment regimen, they found that ginkgo users showed a smaller memory decline and were less likely to have progressed to signs of clinical dementia.

There were seven ischemic strokes or "mini-strokes" among ginkgo users, versus none in the placebo group. However, "the strokes observed in this study were ischemic rather than associated with bleeding or hemorrhage and were generally not severe," Dodge said.

Soon to be publicized findings of the ongoing Ginkgo in Evaluation of Memory Study may shed more light on the role this extract plays in memory function, Dr. Steven T. DeKosky of the University of Pittsburgh School of Medicine, in Pennsylvania, and colleagues write in related commentary.

SOURCE: Neurology, May 2008.