Hormone Replacement Therapy Risks

Many people wonder if there are hormone replacement risks and if there is a difference between synthetic hormones and bioidentical. It can be even more confusing because you may be getting conflicting information from different doctors. 

Hormone replacement therapy risks remain one of the most controversial subjects in women’s health. It became popular in the late 1960s after birth control pills became available and was used to treat osteoporosis and to help relieve menopausal symptoms. It became controversial after the results of a large study showed that some synthetic hormones were doing more harm than good.

This study, called the Women’s Health Initiative, was prompted by the U.S. National Institute of Health in 1991. It included three large clinical trials and one observational study with the purpose of addressing major health issues regarding mortality in post-menopausal women. The clinical trials addressed how hormones impacted cardiovascular disease, cancer, and osteoporosis. Over 160,000 women were enrolled for a period of over 15 years. After the study had been going on for some time, it became apparent that hormone replacement risks far outweighed the benefits and the study was halted. 

During the first years, the study focused on SYNTHETIC hormones which included Premarin, either alone or in combination with various progestogens, or PremPro, another synthetic estrogen, along with medroxyprogesterone acetate (Progestin). The estrogens were manufactured from several different estrogens found in the urine of pregnant mares. The progestogens that were produced were also synthetic, and while they seem similar to the natural progesterone produced by a woman’s body, the molecular structure is completely different.

When the results of these particular studies were published, the adverse risks far outweighed any benefit that they might be providing, and many doctors stopped prescribing them at all. The findings showed:

• 26% increased risk of breast cancer
• 29% increased risk of heart attack or death from coronary disease
• 41% increased risk of stroke
• 200% increased risk of blood clots
• 50% increased risk of dementia

The only benefits that resulted were a 33% decreased risk in hip fractures and a 37% decreased risk of colorectal cancers. Pharmaceutical sales decreased on these drugs by up to 40%.

Conversely, Bioidentical hormones had been used in other countries for many years, and after the Women’s Health Initiative study results were released, began to trend more in the United States. Additionally, the WHI shifted its focus too and concentrated on researching Bioidentical hormones risks. For additional information regarding our Bioidentical Hormone Replacement Therapy Program, click here. 

So, what exactly is a Bioidentical hormone? It is molecularly IDENTICAL to what is naturally produced in the human body. The Women’s Health Initiative study on Bioidenticals showed not only that they are safer and have fewer hormone replacement therapy risks, but also, that they can be beneficial to women’s health. The findings include:

Cardiovascular Benefits

Bioidentical progesterone has been shown to reduce blood pressure in some hypertensive women, as well as ease symptoms of water retention. Progesterone can also improve microcirculation in the body.

Synthetic estrogens are known to increase the risk of blood clots, raise blood pressure, and increase stroke risk. Bioidentical estrogens have not shown any increased risk, nor has it been shown to increase cholesterol formation. Bioidentical progesterone helps to block cholesterol formation.

Synthetic progestins increase the extent of atherosclerosis in coronary arteries and suppress the protective effect of estrogen on an arterial injury. In two of the studies completed on Bioidentical estrogen/progesterone therapy, these combinations protected against coronary hyper-reactivity and subsequent vasospasm. Progesterone and estradiol have also been shown to inhibit cardiac fibroblast growth which suggests that this combination may help to protect postmenopausal women against cardiovascular disease.

Bioidentical progesterone has also shown to be safe with regards to lipid metabolism and blood clotting.

Overall, the research to date on Bioidentical hormones risks has shown they are the preferred therapy to support cardiovascular health.

Breast Health

The study on synthetic hormone replacement therapy showed a 26% increased risk for breast cancer. Conversely, several of the reviews of the Women’s Health Initiative study results show that Bioidentical progesterone may have a protective effect on breast tissue. In a review by Desreux et al, it has been emphasized that progesterone use helps to oppose the proliferative effects of estrogen on the breast.

In another study involving women with benign breast disease, women showed no increased risk of cancer using progesterone and noted that women using a progesterone cream in addition to oral progesterone, actually found a decrease in breast cancer risk.

Another large-scale study on hormones and their effect on breast cancer has been completed in France. This study, called the E3N Cohort, was created to compare different hormone replacement therapies and breast cancer risk. The study lasted 12 years and over 80,000 women were involved. As with the United States study, the use of synthetic estrogen and progestogen hormones risks were significant for breast cancer. The hormone replacement therapy risk is so great, that the combination of synthetic HRT has actually been deemed carcinogenic regarding breast cancer.

Bioidentical estrogen-only therapy and cancer of the breast continue to be the source of debate. The Women’s Health Initiative showed that there was a decreased hormones risks found, but some observational studies have not confirmed this.

The E3N Cohort in France indicates they have done a longer study which doubled the number of cases analyzed. Bioidentical estrogen-only therapy was not considered. They did compare synthetic estrogen/progestin use against Bioidentical estrogen/progesterone use and found again that the use of synthetics significantly increased breast cancer risk. A major finding suggested that the use of estrogen and progesterone together was much safer than estrogen therapy alone. This French E3N study is the first-ever to provide evidence which indicates that Bioidentical combinations of estrogen and progesterone may be the least harmful hormone replacement therapy regarding breast cancer risk.

However, all studies have shown that the use of Bioidentical progesterone is associated with a diminished risk for breast cancer.

Bone Health

Estrogen has long been associated with the treatment of osteoporosis. Now that research has shown that Bioidentical estrogen doesn’t carry with it the same hormone replacement therapy risks as the synthetics of the past, it is used to both treat and prevent osteoporosis in postmenopausal women.

The studies of progesterone therapy to treat osteoporosis have had mixed results, though all have deemed it safe. Several studies have shown that progesterone has a positive effect on bone formation as well as prevention of bone loss, but double-blind placebo studies have yet to demonstrate either with progesterone alone.

Some results are suggesting that using a combination of estrogen and progesterone is the best treatment since they appear to have complementary roles in the maintenance of bone.

Brain Health

The Women’s Health Initiative study results on synthetic estrogen and progestins showed that the risk of dementia more than doubled! However, studies of the effects of bioidenticals on brain health have been positive, especially regarding progesterone.

It has many beneficial effects on both the brain and the nervous system. It plays a role in the reduction of ischemia and also shows that it helps to decrease the inflammatory response after a traumatic brain injury.

Progesterone is also showing promise as a viable therapeutic treatment for neurodegenerative diseases and preservation of cognitive function with age.

The studies have also demonstrated that estrogen alone does not affect cognitive function either positively or negatively. However, Bioidentical estrogens have known benefits on the brain including improved blood flow and the stimulation of serotonin and norepinephrine, which can impact nerve cell function and mood.

At the offices of Leigh Ann Scott, M.D., we ONLY prescribe bioidentical hormones. Our goal is to help you reach your optimum health by treating you both safely and individually and minimize any hormone replacement therapy risks that may be applicable to you. 

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