A study conducted in France provides
preliminary evidence that older people who take
Ginkgo biloba may be extending their lives, but
are not reducing their risk of dementia.
Among 3,534 men and women 65 and older, those who
used the herb were 24 percent less likely to die over
a 13-year period than their peers who didn't take
ginkgo, Dr. Jean-Francois Dartigues at the University
of Bordeaux and colleagues found.
Dartigues and his team note that Ginkgo biloba
extract has been sold in France for more than three
decades to enhance memory. To date, they add, most
studies have focused on whether the herb prevents
dementia, but because older people have a much greater
risk of dying, dementia-free survival should also
be included as an outcome.
The researchers looked at the effect of several
different dementia prevention treatments on the
study participants, collecting data when the study
began, in 1988, and every 2 years thereafter.
At the start of the study, 6.4 percent of the participants
were taking Ginkgo biloba extract, while 25.1 percent
were taking some other type of memory enhancing
treatment. After 13 years, 53.1 percent had died
and 17.6 percent had developed dementia.
About half of people who took no memory enhancing
treatment died, compared with 46.7 percent of those
taking Gingko biloba and 62.1 percent of those taking
some other type of memory-boosting drug. Among those
on Gingko biloba, 21.4 percent developed dementia,
compared with 22.4 percent of those on other memory
treatments and 15.5 percent of those who were not
taking memory enhancers.
The researchers found that while the effect of
the herb on mortality risk remained significant,
it had no effect on the likelihood of developing
dementia. People taking other memory treatments
were actually at increased risk of dementia, but
did not have a greater risk of dying.
These results should be interpreted carefully,
the researchers note, because people taking Gingko
or other memory enhancers at the beginning of the
study may have been at greater risk of dementia
than those who weren't taking such treatment.
"Nevertheless, it cannot be excluded that
Ginkgo biloba may have a beneficial effect on survival
in the elderly population," they write.
The results must be confirmed in randomized, prospective
clinical trials in which people taking the extract
are compared to those who aren't, the researchers
add. They point out that there are currently over
5,800 people taking part in such studies in the
US and Europe, with results expected in 2010.
SOURCE: Journal of the American Geriatrics Society,