Menopausal hormone therapy may shield women from stress' negative effects on some types of memory, according to a small-scale study published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism.
During menopause, many women experience symptoms such as hot flashes, night sweats, sleep disturbances, mood changes, joint pain, recurrent urinary tract infections, and difficult or painful sexual intercourse. These symptoms can start in the years before a woman's final menstrual period and last for more than a decade. One option for treating the symptoms is undergoing hormone therapy containing estrogen, often in combination with progestogen.
"We know estrogen can modify women's hormonal response to stress, and we wanted to test whether such modifications also altered its subsequent effects on memory," said the study's first author, Alexandra Ycaza Herrera, Ph.D., of the University of Southern California (USC) in Los Angeles, Calif. "Our study suggests that estrogen treatment after menopause protects working memory needed for short-term cognitive tasks from the effects of stress."
The researchers recruited participants for the study from the double-blinded, placebo-controlled, randomized Early versus Late Intervention Trial with Estradiol (ELITE), where some women received estrogen therapy for menopausal symptoms and others received a placebo over the course of several years. The ELITE study was led by co-author Howard N. Hodis, M.D. The participants who completed the study included 21 women who had undergone estrogen therapy for nearly five years and a group of 21 women who received the placebo.
The women provided saliva samples so the researchers could measure their levels of cortisol, a hormone associated with stress. During two separate sessions, each participant completed a memory task where they were instructed to remember the final word of each sentence. Prior to one of the sessions, the women submerged their non-dominant hand in ice water for as long as possible, for a maximum of three minutes. During the other session, the women submerged the same hand in warm water before completing the memory test.
Although the women who were receiving estrogen therapy reported feeling more stressed by the cold water exposure than the women who received the placebo, they had lower levels of cortisol than their counterparts following the stress test. Women receiving hormone therapy performed about the same on the memory task, regardless of whether they were exposed to the cold water stressor in advance or not. Women who were taking the placebo performed worse on the memory task following exposure to the cold water than they did when they were not exposed to a physical stressor.
"The findings give us new insight into how estrogen treatment after menopause affects women," Herrera said. "Although more research is needed, this may make estrogen therapy more attractive as a treatment for menopausal symptoms as well as a potential preventative strategy against a host of other age-related declines."