Study: Hormone Replacement Therapy Raises Risk of Alzheimer's Disease

Older women taking estrogen plus progestin have a high risk of developing Alzheimer's disease and other forms of dementia, according to a study reported in the May 28 issue of the Journal of the American Medical Association.

The study found this combination hormone replacement therapy sold under the brand name of Prempro® doubled the risk for probable dementia in women 65 and older and did not prevent mild cognitive impairment.

Of the 4,532 women involved in the study, 61 or 1.3 percent were diagnosed with probable dementia, including 40 who were taking estrogen plus progestin and 21 taking a placebo. About half of the cases in each group were classified as probable Alzheimer's disease.

"The findings translate into 23 additional cases of dementia for every 10,000 women annually, which means the risk to an individual remains low," said study co-author Dr. Rebecca Jackson, an endocrinologist at Ohio State University Medical Center.

But Jackson said the increased risk coupled with the fact that hormone replacement therapy offers no cognitive benefits led the research team to urge women to avoid estrogen and progestin in their efforts to prevent age-associated memory loss.

The study was part of the Women's Health Initiative trial that was halted last July after research results indicated that the overall risks of the combined therapy outweighed the benefits.

Jackson said the study provides further evidence that this hormone replacement therapy could be more harmful than helpful to postmenopausal women.

Other sources: Ohio State University