Your body produces more than sixty different hormones and, without them, you couldn’t live. Hormones are chemical messengers that circulate in your bloodstream and orchestrate the continuous activity in the cells and organs in your body.
From the regulation of your heartbeat and breathing, to the control of your blood pressure and metabolism, hormones are involved. They also help fight stress, soothe pain, calm anxiety, and stimulate your immune system.
Sex hormones such as estrogens, progesterone, and testosterone play important roles in controlling sex drive, regulating the menstrual cycle, and allowing for pregnancy and birth. Sex hormones are also potent “neurosteroids” that help maintain the central and nervous system tissue.
Proper hormone balance is critical to your health, and hormones are the most delicately balanced system in your body. Given the number of hormones that make up this system, and the continual communication between hormones that is necessary to maintain a healthy balance, the literature on hormones is vast. Unfortunately, much of the information available today is inconsistent, and at times misleading, especially with respect to hormone therapy.
Different types of hormone therapy involving various forms of hormones are now prescribed to offset hormonal imbalances, yet the differences between such therapies are not always clear. The goal of this newsletter is to provide a solid understanding of bioidentical (or biologically identical) hormones, along with their uses and benefits.
What Does “Bioidentical” Mean?
Although many bioidentical hormones are created in a lab, they have the exact same molecular structure as the hormones produced by the human body. In other words, they are chemically indistinguishable from one another. Because their chemical structures are identical, bioidentical hormones generate the same physiologic responses in the body as do the hormones already produced by the body. When making choices about hormone therapies, choosing bioidentical hormones makes good sense because they simply replace and replenish the balance your own hormones naturally provide. One well-known example of a bioidentical hormone therapy is the use of injectable human insulin in the treatment of diabetes.
With bioidentical hormone therapies, each individual’s hormone deficiencies or excesses must be evaluated. In determining the optimal hormone therapy for an individual, a practitioner must take into consideration the interactions among the different hormones, as well as other potential effects of each hormone throughout the body. For example, bioidentical progesterone protects the uterus and, at the same time, has positive effects on mood, memory, and sleep.
Bioidentical vs. Synthetic Hormones: The Rest of the Story
We are bombarded with information from television, radio, newspapers, magazines, brochures, and the Internet daily. For many people, these have become their primary sources of information about hormone therapies. However, while it may be helpful, the information disseminated may be only part of the story, or sometimes even biased, based on its sources.
Many studies and media statements discuss hormones in general terms, without making a distinction between bioidentical and non-bioidentical forms of hormones. For example, a clinical study involving medroxyprogesterone (a progestin)—a non-bioidentical form of progesterone — may inaccurately refer to the hormone as “progesterone.” Yet medroxyprogesterone and progesterone differ in their molecular structure, their derivation, and—most importantly—their effects on your body. Therefore, the results from such a study reflect only those of the particular progestin used, and not any other types of progestin, or progesterone itself, which might, in fact, produce different results.
The very studies created to test the safety and benefits of hormone therapies are often responsible for creating misinformation. In some cases, study designs have been faulty, and therefore the results misleading and potentially alarming for women taking hormones. The Women’s Health Initiative (WHI) is the landmark example of a highly publicized study that suffered from flawed design, as well as inadequate screenings of study participants.
The WHI study was developed to study the long-term effects of non-bioidentical estrogens and progestin hormone therapy in postmenopausal women and specifically assess the risk of heart disease, hip and other fractures, and breast cancer. One hormone product used in this study was Premarin, which some consider “natural estrogens” because it comes from pregnant horse urine. However, Premarin’s effects on the human body are different than the effects of bioidentical estrogens. Another hormone product used in the WHI study, Prempro, contains Premarin and medroxyprogesterone (a progestin).
Of the approximately 16,000 female participants in this trial, none were screened prior to the study to determine whether or not their own hormone levels were adequate. The Prempro portion of the study was stopped early due to an increased risk of breast cancer, heart disease, stroke, and blood clots. Soon after, the Premarin portion of the study was also stopped. These results, and the media attention they received, left women and their practitioners alarmed and unsure about what to do. They also raised many questions regarding whether women should continue with their therapy, try alternate therapies, or completely stop their therapy.
Furthermore, the publicity implied that these results applied equally to “all” hormones when, in fact, bioidentical hormones were not included in this study. In addition, some professional medical groups with financial ties to the pharmaceutical industry have promulgated the misinformation that all bioidentical and synthetic hormones behave in the same fashion, disregarding basic principles of physiology.
Another landmark study, the Postmenopausal Estrogen/Progestin Interventions (PEPI) Trial assessed heart disease risk factors in postmenopausal women using hormone therapies. In women, it is believed that high levels of HDL (good cholesterol) protect against coronary heart disease. This study tested three different hormonal regimens:
- Premarin and bioidentical progesterone, which produced the most favorable increases in HDL levels
- Premarin alone, which also produced favorable increases in HDL levels but significantly increased the occurrence of severe hyperplasia in women who still have a uterus
- Premarin and medroxyprogesterone (a progestin), which also led to increased HDL levels although the increases were less significant than those obtained with Premarin alone or Premarin and progesterone
Fortunately, research is starting to include compounded bioidentical hormone preparations. In fact, a November 2011 article in BMC Women’s Health reports on a seven-year-long cohort study of 296 women using various bioidentical estrogen, progesterone, and DHEA treatment strategies. The results confirmed marked improvements in emotional stability, irritability and anxiety, and some improvement in night sweats and hot flashes within 3 to 6 months.