Hormone therapy may prevent -- or contribute to -- dementia risk

November 19, 2010 By Shari Roan

Hormone therapy appears to affect the brain differently depending on the age of the woman when she receives it, researchers reported Thursday.

Hormone-replacement therapy for women has been the subject of considerable debate. Studies have shown both pros and cons. But use has declined in the last decade because a major study on the issue, the Women's Health Initiative, found that the risks of taking hormones appeared to outweigh significantly the benefits in older . Among the findings was that beginning in women ages 65 and older led to a twofold higher risk of .

Questions remain about the effect of hormones if taken at a younger age - among perimenopausal (the phase before when hormones decline and fluctuate) or menopausal women in their early 50s. The new study, published in the Annals of Neurology, supports the idea that hormones can affect dementia risk differently depending on the age of the woman when she takes them.

Kaiser Permanente researchers examined data from members in Northern California from 1964 to 1973, among women 40 to 55 years old. The study examined whether hormones were used at midlife - defined in this study by the average age of 48.7 - or in late life, defined as age 76. Compared with women who never used hormones, those taking hormones only at midlife had a 26 percent decreased risk of dementia. This link held true even when the researchers controlled for other factors that contribute to dementia, such as high and stroke.

However, taking hormones in late life may counteract whatever benefits are seen by taking hormones at midlife, the authors said. Women taking hormone therapy only in late life had a 48 percent increase in dementia. Women using hormones at both midlife and late life did not differ in their dementia risk from women who didn't take hormones.

"The reduced risk of dementia associated with midlife hormone therapy use only lends support to the notion that it is not only early postmenopausal use of hormone therapy that is protective, but that use should also be limited to a few years," the authors wrote.

Animal studies suggest that estrogen benefits health, and observational studies have shown that women who take hormones are less likely to develop dementia later in life. But studies such as the Women's Health Initiative dashed hopes that hormones protected against cognitive impairment. Research now is focusing on whether there is a "critical window" for use - a specific time of life when hormones would do more good than harm.

Explore further: Hormone replacement helps young women


Related Stories

Hormone replacement helps young women

January 26, 2007

The benefits of short-term hormone replacement therapy likely outweigh the risks for younger women, the Ohio-based North American Menopause Society said.

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

(PhysOrg.com) -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.