ANA: High Coffee Intake, Hormone Therapy Increases Risk of Parkinson's
Disease
By Ed Susman
NEW YORK, NY -- October 14, 2002 -- Women who drink more than six cups
of coffee each day and are also receiving hormone replacement therapy
have an increased risk of developing Parkinson's disease, Harvard researchers
reported.
Dr. Alberto B. Ascherio, MD, associate professor of medicine at the
Harvard School of Public Health/Brigham and Women's Hospital, in Boston,
Massachusetts, United States, said the risk is four times that of women
who take hormones after menopause but don't drink as much coffee.
Numerous studies have demonstrated that intake of caffeine among men
is associated with a reduced risk of Parkinson's disease, Dr. Ascherio
noted, but the evidence in women of a protective effect of drinking
coffee and other caffeine-laden drinks has not been established.
Using data accumulated through the Nurses Health Study, which collected
prospective dietary and health information on 77,713 women and followed
them for 18 years, researchers were able to find 154 cases in which
these women developed neurologist-diagnosed Parkinson's Disease.
In analysing their coffee-drinking habits, Dr. Ascherio said the major
finding was that the combination of heavy caffeine consumption and hormone
therapy resulted in a major increase in the risk of Parkinson's disease
among these women. On the other hand his data suggested that use of
hormone therapy and low or absent caffeine consumption is associated
with a protective effect.
"These results suggest that hormone use modifies the effect of
caffeine on the risk of Parkinson's disease," he said in an oral
presentation at the 16th annual symposia on "Etiology, Pathogenesis
and Treatment of Parkinson's Disease and Other Movement Disorders,"
held in conjunction with the 127th annual meeting of the American Neurological
Association.
Dr. Ascherio also suggested that when researchers work on the relationship
between caffeine and Parkinson's disease the interaction between them
"should be taken into account in the interpretation of epidemiological
studies and particularly in the design of clinical trials of caffeine
or oestrogen."
"Among men," he said, "most studies are convincing that
men who drink caffeine have a lower risk of Parkinson's disease. Of
course, we don't know why." He said some research suggests that
in women oestrogen-type hormones and caffeine are both metabolised through
the CYP1A2 pathway and that might explain some of the caffeine-oestrogen
story.
Overall, he noted, hormone use did not have any association with Parkinson's
disease when compared to women who never used hormones. Only when the
relationship was examined by consumption of caffeine did Dr. Ascherio
find an association. He did not see any major differences between no
caffeine use and low caffeine use, just among those women with high
caffeine consumption.
The study was funded by grants from the National Institutes of Health
