Hormone replacement therapy may protect menopausal women from stress-related memory loss, new research suggests.
The sex hormone estrogen buffers working memory from the impact of stress, which is known to impair short-term working memory, according to the study from the University of Southern California (USC).
Women going through menopause take hormone replacement therapy (or HRT) which contains estrogen to offset symptoms such as hot flushes, night sweats, sleep disturbances, mood swings, and reduced sex drive.
But new research offers the first sign that the treatment also blocks fluctuating hormones from affecting memory.
Hormone replacement therapies may protect short term memory from damage caused by stress, a new study shows
First author Doctor Alexandra Herrera of USC said: ‘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.’
‘Our study suggests that estrogen treatment after menopause protects working memory needed for short-term cognitive tasks from the effects of stress.’
Stress prompts the hormonal system and the hypothalamus to release cortisol. This process is called the hypothalamicpituitary-adrenal (HPA) response.
Cortisol interferes with the activity of the hippocampus from making new neurons and neural connections, a process that is key to working memory.
But, Dr Herrera explains that HRT may reduce this response, and thus cortisol, when there are environmental or immune system stressors.
She added: ‘One such deleterious effect of stress is interference with prefrontal cognitive processes such as working memory.
‘Since HRT can reduce the HPA response to stress, the hormone may also mitigate the effects of stress on working memory by limiting the cortisol response to the stressor.’
So the study recruited 42 from the double-blinded, placebo-controlled, randomized Early versus Late Intervention Trial with Estradiol (ELITE).
Half received estrogen therapy for menopausal symptoms and others received a placebo over the course of nearly five years.
The women provided saliva samples so their levels of cortisol, a hormone associated with stress, was measured.
During two separate sessions, each woman 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 HRT 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.
Dr Herrera added: ‘The findings give us new insight into how estrogen treatment after menopause affects women.’
‘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,’ she says.