Low bone density often sneaks up on otherwise healthy women. It is generally asymptomatic until it’s too late and a fracture occurs! Fortunately, non-invasive screening with a DEXA test can identify osteopenia and osteoporosis early. When detected early, a number of strategies can be implemented to regain lost bone density, or at least prevent further deterioration.
The conventional approach to osteoporosis inolves the bisphosphonate medications and selective estrogen receptor modulators, and calcitonin. More recently, immunomodulator denosumab has become available. Whether women have had intolerable side effects from medications, or simply don’t want to take a drug, I often point them towards bioidentical hormone replacement therapy as an option to build bone density (in conjunction with supplementation to ensure the necessary vitamins and minerals are available to make new bone).
Bioidentical hormone replacement therapy, specifically estradiol, is an evidence-based approach that is supported by research and guidelines, despite getting less attention than the drugs. When women pass into menopause, and estrogen levels decline, we see a rapid rate of bone loss that is most dramatic over the first few years of menopause. Estradiol is known to prevent this bone loss and in fact has an FDA approval for the indication of osteoporosis prevention (but not treatment). According to a 2021 review of best practices for endocrinologists, “not only [does] MHT [menopausal hormone therapy] prevent bone loss and the degradation of the bone microarchitecture but it significantly reduces the risk of fracture at all bone sites by 20-40%. It is the only anti-osteoporotic therapy that has a proven efficacy regardless of basal level of risk, even in low-risk women for fracture.1 Thus, some countries, such as the UK guidelines, also include recommendations for the use of HRT for osteoporosis. 2
So, knowing that hormone replacement therapy is a proven strategy for maintaining or improving bone density, how do women know if it is right for them? And if so, what type of hormone replacement should they use?
The first consideration is to weigh the potential risks and benefits of both using hormones and the risks and benefits of not using them. As is usually the case, the answer is not one-size-fits-all; it depends on the individual. In terms of bone protection, estrogen replacement has been shown beneficial in every study from the controversial Women’s Health Initiative study in the early 2000s to the present. The benefit is seen across delivery methods (transdermals, transvaginal, or oral), even at low doses. We’ll get into delivery methods below. Given that the lifetime risk of a woman to have an osteoporotic fracture is 1 in 2 (50%), protecting bone is a high priority for most.
The risk of breast cancer is often top of mind for women considering hormone replacement therapy, and research has been conflicting. Fortunately, a new huge study which included more than half a million women, provides reassurance. “It found that – in line with other evidence – the risks of HRT are generally low. Breast cancer risks were extremely low with oestrogen-only HRT, but this can only be taken by women who have had their womb removed (hysterectomy). Most women take combined HRT which contains oestrogen and progestogen. The type of progestogen in combined HRT made a difference: norethisterone was linked to the highest increases in risk of breast cancer. (That is a synthetic progestogen, which cannot be compared apples-to-apples with bioidentical progesterone). The researchers stressed that some women who had never taken HRT would still get breast cancer. For example, if a group of 10,000 women in their 50s had never taken HRT, 26 women would still get breast cancer in a year. If all 10,000 women had recently taken combined HRT for less than 5 years, 35 would get breast cancer. So, in this large group of women, the HRT is linked to 9 extra cases of breast cancer in a year. That is less than one in a thousand women”. 3
Other health factors that women may need to consider to understand their personal risk/benefit ratio include their risk of other diseases. Oral HRT is associated with a small increase in stroke risk, but transdermal HRT has a largely neutral, possibly protective cardiovascular effect (improves cholesterol ratios, relaxes hypertension). Additionally, HRT protects against colorectal cancer, dementia, and of course life-disrupting symptoms such as hot flashes, vaginal atrophy, insomnia, and mood changes. 4
Fine-tuning the decision to use HRT for osteoporosis can be made by choosing the delivery method associated the lowest risk. It appears transdermal application has less risk that oral estrogens which are associated with a variety of clotting issues such as deep vein thromboses & ischemic strokes. 5 Oral estrogens also negatively impact triglyceride levels and inflammatory markers and require much higher doses to achieve symptom relief. I never prescribe oral estrogens, nor do I recommend forms that are not bio-identical. Even amongst the topical transdermal application methods, there are options. I am one of California’s only certified Menopause Method prescribers, which is a system that uses organic oil as a base for the bioidentical hormones. I prefer this option as it further reduces the risks associated with exposure to parabens, phthalates and stabilizers in the cream bases. For some women, patches or vaginal rings are an option, although these are limited to estradiol (estriol combination is not available).
While every woman must make an informed decision based on her own situation, the majority of symptomatic menopausal women will both improve their quality of life, and reduce their risk of osteoporosis, dementia, and colorectal cancer with the use of bioidentical hormone replacement therapy. Please also see my companion blog post, Optimizing Osteoporosis, which reviews the lifestyle and dietary supplements that reduce the risk of osteoporosis – there are many easy things to implement beyond just hormone replacement therapy.
1 Gosset A, Pouillès JM, Trémollieres F. Menopausal hormone therapy for the management of osteoporosis. Best Pract Res Clin Endocrinol Metab. 2021 Dec;35(6):101551. doi: 10.1016/j.beem.2021.101551. Epub 2021 Jun 2. PMID: 34119418. 2 Gregson CL, Armstrong DJ, Bowden J, Cooper C, Edwards J, Gittoes NJL, Harvey N, Kanis J, Leyland S, Low R, McCloskey E, Moss K, Parker J, Paskins Z, Poole K, Reid DM, Stone M, Thomson J, Vine N, Compston J. UK clinical guideline for the prevention and treatment of osteoporosis. Arch Osteoporos. 2022 Apr 5;17(1):58. doi: 10.1007/s11657-022-01061-5. Erratum in: Arch Osteoporos. 2022 May 19;17(1):80. PMID: 35378630; PMCID: PMC8979902. 3 https://evidence.nihr.ac.uk/alert/risk-of-breast-cancer-with-hrt-depends-therapy-type-and-duration/ 4 https://my.clevelandclinic.org/health/articles/16979-estrogen--hormones 5 https://www.naturalmedicinejournal.com/journal/bioidentical-hormone-replacement-therapy-postmenopausal-osteoporosis