Hormone therapy with either estrogen or testosterone might not affect women's thinking and memory skills in the years soon after menopause, hints a new study.
The findings are the latest addition to a complicated picture of the possible link between hormones and mental functioning in women. Some researchers think hormone therapy may help improve brain function and prevent Alzheimer's disease after menopause. But then there are studies that show little impact on thinking and memory, or different impacts depending on the age of women being treated.
One recent study of women in surgical menopause - when the uterus and ovaries are removed - suggested that estrogen might provide a memory benefit, but that testosterone canceled out some of that benefit when women took both hormones (see Reuters Health story of July 2, 2010: Testosterone may not help memory after menopause).
Since many women during the time of menopausal transition complain about cognitive impairment it has been suggested that estrogen may have a beneficial effect on memory and cognitive abilities, while testosterone is suggested to improve spatial ability but impair verbal memory, Dr. Angelica Linden Hirschberg, one of the current study's authors from the Karolinska Institutet in Stockholm, Sweden, told Reuters Health by email.
Estrogen declines in women as they enter menopause and in the years shortly after, but testosterone levels don't change very much around menopause. Still, both hormones have been used to treat symptoms in postmenopausal women - estrogen to prevent hot flashes and osteoporosis, and testosterone for women who lose their sex drive around this time.
Hormone therapy took a hit in 2002, however, when the Women's Health Initiative study was halted because women taking hormones had higher rates of heart disease, stroke, and breast cancer than women not on hormones.
The pluses and minuses of hormone therapy remain controversial, especially when it comes to its effect on the mind. To try and shed more light on this area, Hirschberg and her colleagues divided 200 women between 50 and 65 years old into three groups. One group took estrogen pills, another took testosterone pills, and a third took placebo pills that didn't contain any hormones. None of the women knew which kind of pill they were taking.
After four weeks of daily treatment, the women were given three thinking and memory tests: in one, they had to list all the words they could think of that started with one letter; in another, they were told to repeat a list of 12 random words; and in the third, they looked at objects on a page and had to choose what that object would look like when it was rotated.
Women in each of the three treatment groups fared similarly on all tests, leading Hirschberg to conclude that short-term treatment with estrogen or testosterone does not affect the mental functions she and her colleagues were evaluating.
The researchers didn't test the women before they started the treatment. But they assumed that because the participants were similar across most other measures, there should be no difference in their thinking and memory skills before some started hormone therapy, they write in the study, which is published in Fertility and Sterility.
Dr. Victor Henderson, an epidemiologist and neurologist at Stanford University, said the study's finding of no relationship between hormone therapy and cognitive skills, at least in the short term, tend(s) to be consistent with the other studies that are coming out.
However, he said, data are lacking on the longer term effects of estrogen and testosterone in postmenopausal women. A four-week study may or may not generalize to studies for a longer duration of treatment, Henderson, who was not involved with the current study, told Reuters Health.
The major unanswered question is whether prolonged hormone exposure...has effects that might show up a decade, two decades, three decades later in terms of things like Alzheimer's risk, he said.
Estrogen pills like the ones used in the study can be purchased over-the-counter for less than 50 cents a day. Testosterone pills cost $2-3 per day, but aren't approved by the Food and Drug Administration for treatment in women. The current study did not mention any side effects from either type of hormone therapy.
While it's still not clear whether hormone therapy can help women improve their brainpower after menopause, Hirschberg said that there are steps women can take to help them stay sharp, including eating a healthy diet and getting regular exercise.