Conjugated estrogen (CE) compliance has been poor in patients since studies showed that the risks of cardiovascular disease and breast cancer are increased in patients on CE. Patients and doctors are looking for alternatives to CE for treatment of menopausal symptoms and reduce or prevent osteoporosis.
Wuttke, et al, conducted a double blind study to evaluate the effects of black cohosh herb (CR or Cimicifuga racemosa) in treated postmenopausal women. In a 12-week study with only 62 patients, the CR treated patients were compared to conjugated estrogen (CE) treated patients and to placebo treated patients. The herbal CR was used at 40 mg/day and the CE dose was 0.6 mg/day.
The markers used to evaluate black cohosh were bone metabolism, hormones, sex hormone binding globulin (SHBG), lipid metabolism and vaginal maturity. Serum total cholesterol, HDL-cholesterol and LDL-cholesterol were not altered by CR or CE treatments. Triglyceride levels were increased in CE and CR treated patients as compared to placebo controlled patients.
Blood samples were tested for bone-specific alkaline phosphatase, estradiol, follicle-stimulating hormone, leuteinizing hormone, SHBG, triglycerides, total cholesterol, high-density cholesterol, low-density cholesterol and routine chemical studies. Studying vaginal smears tested vaginal maturity.
The CE patients showed increased hormone and SHBG levels. And the CR patients did not. Black cohosh extract did not show hormonal activity and it is now known that CR does not bind to estrogen receptors, therefore, CR extracts do not have estrogenic activity.
Women who received both CE and CR had beneficial effects on bone factors. CR had anabolic, or bone building, effects. Estrogen, also, showed anabolic effects, but estrogen’s bone absorption effects tended to predominate.
Women who took CR had some improvement in the growth of vaginal tissues and those who took CE had “significant” improvement in vaginal tissues.
Both, CE and CR showed an effect of increasing triglyerides but neither caused changes in cholesterol.
No liver abnormalities or signs of liver toxicity were seen with CR.
The way that CR works is not known, but it is suspected to be by a serotonin blocking effect in the hypothalamus.
CONCLUSION: Black cohosh (Cimicifuga racemosa) showed some beneficial effect on bone remodeling and weak estrogen-like effects on vaginal mucosa. Conjugated estrogens (CE) showed beneficial effects on bone remodeling. CR may have antiosteoporotic activity. The CE showed significant improvement in vaginal tissues.
NOTE: The authors did not reveal the exact composition of the extract of Black cohosh used, but noted that little is known about the chemical components of CR extracts. The differences between the various known extracts have not been studied.
Rebuilding is a continuous process of breaking down old bone and remodeling at the same time. CR seems to primarily benefit the building up activity and conjugated estrogen (CE) has a predominant catabolic or breaking down activity.