New research suggests women who begin to use the hormone estrogen before age 65 may decrease their risk for developing dementia or Alzheimer’s.
Researchers discovered women who used any form of estrogen hormone therapy before the age of 65 were nearly 50 percent less likely to develop Alzheimer’s disease or dementia than women who did not use hormone therapy before age 65.

The study was part of the Women’s Health Initiative Memory Study, which is a sub-study of the Women’s Health Initiative (WHI), one of the largest U.S. prevention studies of postmenopausal women.

The study looked at prior hormone use in 7,153 healthy women ages 65-79 before they enrolled in the WHI Memory Study. Researchers followed the women’s cognitive health over an average of five years.

In that time, 106 of the women developed Alzheimer’s disease or dementia. Dementia is a general term referring to the progressive decline in a person’s cognitive function. Dementia can affect memory, attention, language and problem solving abilities. Alzheimer’s is the most common type of dementia.

Prior studies have shown that hormone therapy started during the WHI Memory Study increased a woman’s chance of dementia. The reduced risk of dementia was seen only with prior hormone therapy, used before study enrollment. Reduced risk was not affected by other examined factors.

Women who began estrogen-only therapy after the age of 65 had roughly a 50-percent increased risk of developing dementia. The risk jumped to nearly double for women using estrogen-plus-progestin hormone therapy.

“Further studies are needed to support these findings and learn more about how hormone therapy affects the long-term cognitive health of women who begin use before age 65,” said Henderson.

Source: American Academy of Neurology