In younger women, the drug has no negative effect on memory or the ability to think clearly, which can be a side effect for women over 65 who take hormones.
Nearly all previous hormone replacement therapy studies have involved older women, researchers said.
“While we saw there was a wealth of data, a lot of it might not be applicable to young women,” said Mitch Harman, director of the nonprofit Kronos Longevity Research Institute.
Researcher and physician JoAnn Manson said it is important to pay attention to the concerns of women who just recently reached menopause.
“We learned a great deal about what matters to young women and what is important to them for improving their quality of life,” she said.
The double-blind placebo study involved 727 healthy women ages 42 to 58 and was conducted over four years. The findings revealed additional benefits of low-dose estrogen pills and patches.
Both the low-dose pills and patches led to improvement in bone density and a lessening of night sweats and hot flashes. Furthermore, women who took low doses of estrogen by pill reported improvement in sexual functioning, including an increased libido as well as less pain and more satisfaction during intercourse.
“This was very exciting,” said researcher Hugh Taylor of Yale University’s school of medicine. “It’s very important to women but often overlooked in studies of hormone treatment.”
Women taking low-dose pills also reported fewer feelings of anger and hostility than those in the patch or placebo groups. On the other hand, the patch improved insulin sensitivity.
Increased blood pressure, a common negative side effect of HRT, did not occur in lower doses delivered by pill or patch. Furthermore, low-dose pills led to an increase in HDL (“good”) cholesterol and a decrease in LDL (“bad”) cholesterol. However, an increase in triglyceride levels did occur.
Since the patch and pill varied even in their positive benefits, each woman’s needs should be assessed individually.