A new study led by Alexandra Ycaza Herrera at the USC Leonard Davis School of Gerontology, suggests that estrogen therapy after menopause enhance the memory that is required for short-term cognitive tasks from the effects of stress.On combining estrogen and progesterone in the therapy, the researchers observed an increased risk of breast cancer, stroke, heart disease, and blood clots. However, the potential risks of the therapy were highlighted in the previous studies. The study findings are published in the Journal of Clinical Endocrinology and Metabolism .
Women on estrogen-therapy had lower levels of cortisol (stress hormone). Besides, on comparing the women taking a placebo, the women on hormone therapy performed better on tests of "working memory " following exposure to stress.
Working memory allows the brain to keep information immediately available for processing. Studies have documented that stress can impair working memory.
In the study, 42 women (mean age 66 years) from the USC Early were recruited by Ycaza Herrera and compared with Late Intervention Trial with Estradiol led by Howard Hodis. The effect of estrogen therapy on working memory under stress was measured. During a 5-year follow-up study, 50% of the postmenopausal women were on estradiol therapy while the remaining women were given a placebo.
The enrollees visited USC twice, where they were induced stress during the visits. During one visit, the participants were asked to submerge their hand in ice for 3 minutes to induce a stress condition. During the second visit, the participants were asked to submerge their hand in warm water to induce control condition.
The researchers collected saliva before and after every visit. The saliva was measured for the women's levels of cortisol, progesterone, and estrogen. "Sentence span task," a test of working memory was used to examine the women. In the test, women were each given a series and asked whether each sentence was sensitive. Besides, they were asked to recall the last word of each one. All women performed equally well on the sentence span task after the warm water condition.
Hormone replacement therapy might be beneficial in enhancing a certain type of memory in women taking hormonal therapy.