Women's Health: Hormones reduce Alzheimer's risk

The same study that showed the risks of hormone replacement therapy (HRT) outweigh the benefits for older women has now indicated postmenopausal women who take hormones before age 65 may decrease their risk of developing Alzheimer's disease.

Earlier, the Women's Health Initiative (WHI) had revealed that HRT decreases older postmenopausal women's risks for developing osteoporosis but increases their risks for heart disease and breast cancer as well as Alzheimer's disease and other forms of dementia.

More recently, a sub-section of that research called the WHI Memory Study followed more than 7,000 women age 65 to 79 for five years. None of the participants had dementia initially, but 53 were later diagnosed with Alzheimer's disease and 53 with other forms of dementia. About 2,200 women had previously used HRT in the form of a combined estrogen-progesterone pill or estrogen alone.

"Prior use of hormone therapy was associated with significantly lower risk of Alzheimer's disease," says Dr. Victor Henderson, a study co-author and neurologist at Stanford University in Palo Alto, Calif. Women who had used HRT before age 65 were 64 per cent less likely to develop this type of dementia.

The decreased risk was seen only with prior use of hormones -- before age 65 -- not current use. Furthermore, the reduced risk applied only to Alzheimer's disease and not other forms of dementia. The type of hormone therapy used did not affect the outcome, nor did the time since stopping therapy.

The findings indicate a need for further research on the effects of HRT on the brain, Henderson says.