True confession time: Just when I thought I had made peace with the Great Post-Menopausal Hormone Decision -- in my case, sticking with very low dose oral hormones, despite the risks revealed in a 2002 study -- I have plunged into the murk again.
This time, my curiosity and my game plan are focused on "bioidentical" hormones, which are synthesized from soy and yams. They are made to be very similar to the hormones your body already produces -- much more similar, for instance, than the hormones post-menopausal woman swallowed in pills like Prempro and Premarin.
Proponents argue that this close similarity means bioidentical hormones won't have the dangerous side effects of oral hormones such as Prempro. The 2002 study found that Prempro modestly increased the risk of breast cancer, heart disease, stroke and blood clots.
But some mainstream researchers are leery. Dr. JoAnn Manson, chief of preventive medicine at Brigham and Women's Hospital in Boston, called the research on bioidentical hormones "very, very sparse" and warned that women should not flock to them.
"We need to be cautious about not repeating the debacle that occurred with conventional hormone therapy," said Manson, a leader in the 2002 research on standard hormone replacement therapy.
In a September newsletter, doctors from the Mayo Clinic similarly warned that "hormones aren't safer or better just because they're labeled natural or bioidentical."
So why am I even considering replacing oral hormones with something "bioidentical"?
Because I like the way they're delivered. The only way to get a "bioidentical" substance -- that is, an exact chemical match to something the body already makes -- into the system is non-orally, chiefly through the skin, via patches, creams, lotions or gels. Medicines taken orally don't enter the bloodstream in the same form that you take them because they pass first through the liver, where their chemical structure is altered. Medicines taken transdermally do not pass through the liver first en route to the bloodstream and hence are not altered.
When a woman takes oral estradiol, the hormone that declines precipitously at menopause, it is converted in the liver to estrone, a weaker hor-mone, said Dr. Alan Altman, a menopause specialist in private practice in Brookline. By contrast, when estradiol is taken transdermally, it gets right into the bloodstream as estradiol.
