Any woman interested in bio-identical hormones should know the difference between natural hormones (bhrt) and synthetic hormones (hrt). Bio-identical hormones are derived from yams or soy and are the chemical replicates of the exact hormone found in the human body. Synthetic hormones such as Premarin and Provera are drugs made and patented by drug companies. Some of these hormones are derived from pregnant horses urine. The chemicals used are similar to our hormones but have been changed slightly in order to be patented.
Bio-identicals cannot be patented because the drugs have been available for over 15 years. Since bio-identicals can't be patented there is no way for the drug companies to make large amounts of money on them.
Many drug studies have been preformed on synthetic hormones.
The Women's Health Initiative study (WHI) was preformed in 2002 and was stopped early because of the findings. The study involved thousands of women from multiple sites all over the country. The research was done on diet, exercise, calcium supplements, and synthetic hormones. The results were that these drugs should not be given to prevent heart disease, strokes, venous thrombosis, or breast cancer. The findings showed they may increase a woman's risk of developing these problems over time.
The problem with most studies is that the drug companies are funding the study. Therefore, if bio-identicals can't be patented, then the drug companies are not going to spend money on a study.
If you research bio-identical hormones, you can find drug studies on them.
Breast cancer and BHRT
Androgens and Mammary growth and neoplasia
Antiestrogen action of progesterone in breast tissue
Cancer and Hormonal balance
Epidemiology of breast cancer
Hormones in the etiology and prevention of breast and endometrial cancer
This is only 5 examples of the hundreds of studies found on Dr. Rebecca Glaser's website, hormonebalance.org. Dr. Rebecca Glaser also has studies on other topics (not just breast cancer) such as cortisol, estriol, dosage delivery, Testosterone and progesterone to name a few.
My belief is that bio-identical hormones bring the menopausal or pre-menopausal woman back to the hormone levels found in a youthful woman. By doing this, the drugs have shown an improvement in heart health, skin, hair, and memory.
Two other benefits are they slightly lower cholesterol and they will keep bone density from decreasing further. Other than relief from the normal menopausal symptoms (hot flashes, night sweats, etc.) I believe bio-identical hormones can also help with heart, bones, memory and cholesterol. I do not think they will decrease the risk of breast cancer, but taken in the correct dosage amount I think they do not increase the risk of cancer.
In other words, if you are on the correct strengths of hormones there will be no increase or decrease in cancer risk.