Alzheimer's disease and estrogen

Alzheimer's disease is a common, progressive, degenerative disease of the brain. It is characterized by loss of memory and other cognitive functions.

Menopause is a stage of life when a woman stops having periods for twelve or more months and her body makes little estrogen.

In the past, women were often routinely advised to take estrogen hormone therapy. This therapy has many benefits, especially in relieving the symptoms of menopause, and it preventing osteoporosis (thinning of the bones). However, new health risks of estrogen therapy have been discovered, and clinicians disagree about the advisability of estrogen (or estrogen and progesterone) therapy for women in different situations. It is important for each woman to review her needs carefully with her healthcare professional.

At one time, it was suggested that estrogen therapy might prevent or delay the onset of Alzheimer's disease. More recent studies, however, have not supported this theory.

Earlier research suggested a possible role for estrogen in preventing Alzheimer's disease in women. One study showed that women who took estrogen after menopause were less likely to develop Alzheimer's disease. It also suggested that Alzheimer's disease might occur later in life among women who take estrogen. Women who have never taken estrogen may have Alzheimer's disease at an earlier age.

This research, however, was limited and of less-than-ideal quality. Other research done with animals suggested that estrogen might have the following effects:

Studies assessing the relationship between estrogen therapy and Alzheimer's disease have continued to be published over the last several years. The best evidence now indicates that estrogen therapy does not help prevent Alzheimer's and in fact, in some women, might possibly have the opposite effect.

Any woman considering using estrogen therapy must remember that it, like any long-term medication, has risks, benefits, and possible side effects. For example, estrogen therapy may increase the risk of blood clot, heart attack or stroke. There is also an increased risk of cancer of the uterus if a woman takes estrogen and has not had her uterus surgically removed. This risk can be eliminated if a woman who still has her uterus takes a form of the hormone progesterone along with estrogen.

Estrogen therapy does help with symptoms of menopause, such as hot flashes and vaginal dryness. It can also reduce the risk of the bone-thinning condition called osteoporosis and broken bones that can result from that disease.

All women should discuss estrogen therapy use after menopause with their healthcare professional to decide if the benefits outweigh the risks for them. New data about the risks and benefits are still being generated. At this time, however, the data do not support its use to prevent or treat Alzheimer's disease.