The National Institute on Aging has announced a phase III trial of the estrogen hormone as a possible treatment for -- and aid in preventing -- Alzheimer's Disease.

The double-blind study will involve about 1,000 post-menopausal women over the age of 65, who will randomly receive estrogen or a placebo, and will be followed for five years.

Women wishing to participate in the study must have a history of the
disease, but no memory loss themselves. People with a history of breast, ovarian and uterine cancer, and those who have received estrogen or hormone replacement therapy in the last year, are ineligible.

In the past, estrogen has had an advantageous effect on brain cells.
Research in laboratories and clinical trials has shown that estrogen
improves both cognitive function and mood levels in women.

Although researchers remain unclear how it works in the brain, they believe it protects nerve cells, perhaps even preventing nerve death.

Other sources: National Institute on Aging, Alzheimer's Disease Education and Referral