Ginkgo may not aid memory in healthy older adults

NEW YORK (Reuters Health) - The popular herbal supplement ginkgo biloba may not do much for healthy older adults’ memory, at least in the short term, a new study suggests.

Extracts of ginkgo biloba are among the most widely used dietary supplements. The herb is marketed as a memory enhancer, and some studies have suggested it may help improve memory and other mental functions in people with dementia.

Meanwhile, many older adults, while not suffering from dementia, do develop milder problems with memory, concentration and other mental functions -- and so far, studies have come to mixed conclusions as to whether ginkgo can slow such age-related cognitive decline.

The new findings, published in the Journal of the American Dietetic Association, suggest that healthy older adults are unlikely to see any quick results from ginkgo.

Among the 90 men and women ages 65 to 84 in the study, those who took a ginkgo-containing supplement every day for 4 months performed no better on tests of memory, attention and other cognitive functions than those who took an inactive placebo.

Overall, this and other well-designed studies suggest that, in the short term, ginkgo biloba does not benefit healthy older adults’ cognitive function, according to lead study author Dr. Joseph J. Carlson of Michigan State University in East Lansing.

However, it’s still possible that there are benefits over the long haul, Carlson said, noting that results from a 5-year study funded by the National Institutes of Health will soon be published.

For older adults who don’t want to wait to try ginkgo, some caution is in order. As with any supplement, Carlson told Reuters Health, ginkgo users should tell their doctors that they’re taking it.

Supplements can interact with each other or with any medication a person may be taking, and that possibility should be taken seriously, Carlson said. With ginkgo, the primary concern is its potential to interact with drugs or supplements that may “thin” the blood -- including aspirin and other non-steroidal anti-inflammatory drugs, like ibuprofen and naproxen, as well as supplements like vitamin E and garlic.

This is based on evidence from past research that ginkgo may interfere with the functioning of blood cells called platelets, which play a key role in clot formation; impaired platelet function could raise the risk of bleeding.

In their study, Carlson and his colleagues found no evidence that the ginkgo supplement altered participants’ platelet function. However, Carlson said that people already on aspirin or other products that thin the blood should be particularly cautious about adding ginkgo to the mix.

SOURCE: Journal of the American Dietetic Association, March 2007.