TUESDAY, March 18, 2003 (HealthDayNews) --
Women who take hormone therapy and consume little or no caffeine may have a reduced risk of developing Parkinson's disease.
So says a Harvard School of Public Health study in the March 11 issue of Neurology.
However, the risk of developing Parkinson's may increase in women who take hormone replacement therapy (HRT) and drink more than 5 cups of coffee a day.
Two large previous studies found the risk of Parkinson's disease for men decreases when they increase their caffeine intake.
Studies in women looking at the link between caffeine intake and Parkinson's have been contradictory and inconclusive. Those studies did not factor in the use of HRT.
This new Harvard study examined 18 years of data from 77,000 women included in the Nurses' Health Study. The Harvard researchers collected data on hormone use and caffeine intake.
They found that 154 women were diagnosed with Parkinson's disease during the Nurses' Health Study. When HRT was the only variable considered, there was no difference in the incidence of Parkinson's between women who did or did not use HRT.
But when caffeine consumption was also factored in, there were some unexpected results. In women who drank less than a half cup of coffee a day, women who used HRT had a 65 percent reduced risk of developing Parkinson's disease, compared to women who didn't use HRT.
In women who drank more than five cups of coffee a day, women who used HRT had a 150 percent greater risk of Parkinson's, compared to women who didn't used HRT.
More information
Here's where you can learn more about Parkinson's disease.
