Two new studies report that hormone therapy—a still commonly prescribed form of postmenopausal treatment—may slightly accelerate the loss of brain tissue in women 65 and older, beyond what normally occurs with aging. “This is not what we expected to find,” reported one of the researchers.

The investigating scientists, using MRI scans to look for increased volumes of brain lesions among women who had taken hormone therapy, discovered their brain volume had shrunk in two critical areas: the frontal lobe and the hippocampus. Both of these areas are involved in thinking and memory skills. Loss of volume in the hippocampus is also a risk factor for dementia. More than 1,400 women ages 71 to 89 participated in the study.

Source: Wake Forest University Baptist Medical Center, 2009