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Originally published January 21 2009

Hormone Replacement Therapy Makes Brains Shrink

by Sherry Baker, Health Sciences Editor

(NaturalNews) Two new studies just published in Neurology, the medical journal of the American Academy of Neurology, have both good news and bad news for women who take or have taken hormone replacement therapy . One study says the hormone treatment isn't linked to small brain lesions which are the first sign of cerebrovascular disease. But before menopausal and post-menopausal women on HRT breathe a sigh of relief, consider this: the second study concludes hormone therapy appears to cause brain shrinkage.

HRT producing a negative impact on the brain isn't a new idea. Previous studies have concluded that estrogen with or without added progesterone increases the risk for developing dementia and difficulty with thinking skills and memory ( technically called "cognitive decline") in women age 65 and older. The new research looked at how the hormones impact memory and thinking skills, using participants of the Women's Health Initiative hormone therapy clinical trials who also agreed to participate in a spin-off study known as the Women's Health Initiative Memory Study. These HRT trials were stopped earlier than planned when scientists found that HRT presented dangers to study participants because it increased health risks and didn't prevent heart disease.

A research team from the National Institute on Aging took MRI brain scans of 1,400 women ages 71 to 89 one to four years after the Women's Health Initiative hormone studies ended. The brains of women who had taken estrogen with or without progesterone were significantly smaller in two areas of the brain, the frontal lobe and the hippocampus, when compared to the women who had taken a placebo. The frontal lobe and the hippocampus are parts of the brain involved in thinking and memory. What's more, loss of volume in the hippocampus is a known risk factor for dementia.

"These effects were most apparent in women who may already have had some memory problems before they started taking hormones," said study author Susan Resnick, PhD in a media statement. "This suggests that estrogen may adversely affect thinking skills among women whose brains may already be beginning a neurodegenerative disease process."

In the second study, Wake Forest University Health Sciences researchers found that hormone therapy was not linked to an increase in small vascular lesions in the brain, also called "silent strokes" or "mini strokes", which are often an early sign of cerebrovascular disease. "This was not what we expected to find," study author Laura H. Coker, PhD, said in a press release. She added that the negative effects of hormone therapy on thinking and memory may not be the result of vascular disease but to neurodegeneration -- an idea supported by the first study's findings of brain shrinkage in women who took HRT.

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About the author

Sherry Baker is a widely published writer whose work has appeared in Newsweek, Health, the Atlanta Journal and Constitution, Yoga Journal, Optometry, Atlanta, Arthritis Today, Natural Healing Newsletter, OMNI, UCLA's "Healthy Years" newsletter, Mount Sinai School of Medicine's "Focus on Health Aging" newsletter, the Cleveland Clinic's "Men's Health Advisor" newsletter and many others.

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