"The jury is still out on this," says Dr. Sandra Davidge, the Canada Research Chair in Women's Cardiovascular Health at the University of Alberta. "This question still requires a lot of investigation, but what we're seeing is that the timing of the hormone replacement is probably critical to any potential cardiovascular benefits."
The benefits of HRT were very publicly called into question in 2002 with the release of the Women's Health Initiative study. The study, which made front-page news, reported that women on HRT actually had an increased rate of heart disease.
The results, says Davidge, pushed researchers to take a harder look at the timing of HRT. She notes that the heart and blood vessels have specific receptors, or contact sites, for the sex hormone molecules that are lost with menopause. Many of those in the Women's Health Initiative study received HRT years, or even decades, after menopause.
"In many of these cases, the estrogen was probably given too late," Davidge says. "If you give estrogen to aged blood vessels it might not be protective and it might have detrimental effects. But if you give it to women at the onset of menopause it probably has benefits."
That's the conclusion of research, funded by the Canadian Institutes of Health Research, in Davidge's lab on the role of estrogen in maintaining blood vessel health in animal models of menopause.
"We've found in our lab that estrogen acts as a powerful antioxidant and also suppresses some of the proteins that cause inflammation, thereby having a positive effect on the arteries," she says.
This raises the possibility that HRT might be effective in extending cardiovascular health if it's given at the onset of menopause, before the blood vessels have deteriorated."
Instead of pushing HRT on women, maybe it would make sense to look into foods that naturally boost estrogen (ie, soy) and think about gradually increasing amounts of this in the diet as women enter perimenopause.
Some more perspective on HRT and women's cardiovascular health:
Perspectives on the risks of HRT
Preventing Heart Disease: the Natural Approach