Women who take long-term hormone replacement therapy are less likely to develop Alzheimer's disease.

It has long been argued that the estrogen in hormone replacement therapy (HRT) can protect the brain from dementia - but research has given conflicting results. In what may be the most definitive study to date, researchers in the US now reveal that long-term HRT is protective.

They studied rates of Alzheimer's disease between 1995 and 2000 in 1,357 men and 1,889 women, all elderly. They found that women on HRT for at least a decade were 2.5 times less likely to develop Alzheimer's disease than women who had never used HRT. The rates of the women on HRT were similar to those among the men in this study.

The study also showed that vitamin and calcium supplements had no effect on Alzheimer's risk. The study showed that there is no protective benefit from HRT unless it was begun several years before the onset of mental decline. This suggests that estrogen can only protect the brain before damage has begun. More research is now needed to see what the best 'window of opportunity' is for using estrogen to reduce Alzheimer's disease risk.

Source

Journal of the American Medical Association 6th November 2002