HRT & Brain Health, Disease Prevention, and Questions to Ask Your Doctor

From Alzheimer's research to the controversy over HRT as a preventative therapy, Part III completes the HRT picture and gives you the tools to take to your next doctor's appointment.

Your choice about HRT in perimenopause can impact your health for decades.

In Parts I and II of this series, we examined how a flawed 2002 study caused women to lose faith in and access to HRT, and why the specific fears around breast cancer and heart disease do not hold up under scrutiny.

In this final part, we turn to a frontier that is still emerging: the relationship between hormones and brain health. We will also explore why HRT is still not prescribed to prevent the diseases it demonstrably helps.

The brain and the menopause transition

Estrogen's reach within the body is vast. According to Johns Hopkins Medicine, estrogen affects the reproductive tract, urinary tract, heart, blood vessels, bones, breasts, skin, hair, mucous membranes, pelvic muscles, and the brain. It plays a role in memory, cognition, temperature regulation, healthy metabolism, and reducing inflammation. When estrogen declines during perimenopause, the neurological effects like brain fog, anxiety, disrupted sleep are among the most disruptive symptoms women describe.

Research into whether HRT can protect against long-term cognitive decline and Alzheimer's disease is newer and less prolific than the cardiovascular and bone research. The WHI study found an overall increased risk of dementia with HRT use but this, again, was in a population of women with an average age of 63. When the 50–59 age group was examined separately, the data "provided important evidence that HRT started in midlife may indeed help to reduce the risk of dementia."

A meta-analysis by 15 prominent scientists reviewing six randomised controlled trials (RCTs) reached a cautiously encouraging conclusion: that estrogen therapy begun during the menopause transition may support neurological function and reduce Alzheimer's risk.

"Results suggest that estrogen therapy initiated during the critical window of the menopause transition may support neurological function and reduce the risk of future Alzheimer's Disease among eligible women." - Nerattini et al., Frontiers in Aging Neuroscience, 2023 (meta-analysis of 6 RCTs)

Leading brain researcher Dr. Lisa Mosconi, in The Menopause Brain, describes the biology clearly: HRT works best when the brain is still receptive to estrogen, a window that exists during and shortly after the menopause transition, but not long after.

Mosconi is honest about the limitations of what is known. In the absence of more definitive findings from large clinical trials specifically designed to test HRT for dementia prevention among perimenopausal women, it cannot yet be recommended for that purpose. The research, she and her colleagues hope, will follow.

The prevention question: a system that fails women

The evidence that HRT protects against osteoporosis is substantial and long-standing. The evidence supporting cardiovascular benefits, when started at the right time with body-identical formulations, is accumulating. Yet, current guidelines in most countries do not recommend HRT to prevent disease in women without menopausal symptoms.

In 2022, the US Preventive Services Task Force (USPSTF) gave HRT a grade of D for prevention of chronic disease in postmenopausal women. The analysis included data from nearly 39,000 patients of whom fewer than 1,000 came from studies using body-identical estradiol. The rest came from WHI analyses, using conjugated equine estrogen.

"The recommendations perpetuate egregious harm to the public health." - Langer et al., Climacteric, 2017 in response to USPSTF's D-rating for HRT

The implications of that D-rating are profound. It means that a woman at significant risk of osteoporosis or cardiovascular disease, who has no vasomotor symptoms, will likely not be prescribed HRT by a physician following standard guidelines, even though the evidence on bone and cardiovascular outcomes is compelling.

The Gold Standard of HRT

For women who are candidates for HRT, the modern evidence points towards body-identical formulations.

Hormone specialist Dr. Louise Newson summarises the current consensus: "The safest and most regulated type of HRT is body-identical HRT." This means transdermal estradiol, absorbed through the skin, bypassing the liver, and associated with a lower risk of stroke and blood clots than oral estrogen.

It means micronised progesterone, structurally identical to what the body produces, rather than synthetic progestins. The ESTHER study confirmed no increased risk of venous thromboembolism with transdermal estrogen and micronised progesterone, compared to oral and synthetic formulations.

Women should also be aware that compounded bioidentical HRT, produced outside regulated channels, should be avoided. Regulated, body-identical HRT is the evidence-supported option.

Key questions to raise with your doctor:

• Am I within 10 years of menopause, or under 60? (The timing window for maximum benefit)

• Do I have any true contraindications? (Family history alone is not a contraindication)

• Can we discuss transdermal estradiol and micronised progesterone specifically?

• What are the risks of not treating my symptoms — for my bones, heart, and quality of life?

• What would be an individualised assessment of my specific health history?

• Are the risks being cited from the 2002 WHI study, or from more recent evidence?

A note on contraindications

HRT is not appropriate for everyone, and assessment must always be made with a qualified doctor who can review individual medical history.

Genuine contraindications include pregnancy, unexplained vaginal bleeding, active liver disease, uncontrolled hypertension, known or suspected hormone-sensitive cancer, and active arterial or venous thromboembolic disease.

Crucially, having a family history of any of these conditions is not itself a contraindication.

The method of delivery, transdermal versus oral, can significantly affect risk profiles for conditions such as stroke and blood clots.

The stakes of getting this right

In 2002, a study changed the course of women's healthcare based on findings that were misinterpreted, overgeneralised, and applied to populations for whom they were never intended.

As Hodis and Sarrel concluded in their 2018 review, considerable damage to women and women's health has occurred through this misinterpretation. Women became reluctant to use HRT and healthcare providers became reluctant to prescribe it.

The women who lost out on treatment in those intervening decades cannot be given that time back. However, the next generation of women approaching perimenopause, and the clinicians who care for them, can be better informed.

The evidence that HRT, in body-identical formulations, timed appropriately, relieves symptoms and supports long-term health is substantial. The recommendation of every major menopause society, British, European, Australian, North American, now reflects that evidence.

What remains is for women to use this information to advocate for themselves, and for healthcare systems to update their guidelines accordingly. As the evidence repeatedly shows, not taking HRT also comes with risks.

This series (Part I, II and III) draws solely on peer-reviewed research, published clinical trials, and statements from recognised menopause societies. It is intended as an informational resource. All decisions about hormone replacement therapy should be made in consultation with a qualified healthcare provider who can assess your individual medical history.

← Read Part I: The HRT study that left a generation of women to suffer in silence

← Read Part II: HRT & Breast Cancer, Heart Disease, and Bones: Separating Fear from Fact

Sources

Mosconi, The Menopause Brain Mosconi L. The Menopause Brain. London: Atlantic Books, 2024.

Nerattini et al., Frontiers in Aging Neuroscience 2023 Nerattini M, Jett S, Andy C, Carlton C, Zarate C, Boneu C, Battista M, Pahlajani S, Loeb-Zeitlin S, Havryulik Y, Williams S, Christos P, Fink M, Brinton RD, Mosconi L. Systematic review and meta-analysis of the effects of menopause hormone therapy on risk of Alzheimer's disease and dementia. Frontiers in Aging Neuroscience. 2023 Oct 23;15:1260427. doi: 10.3389/fnagi.2023.1260427. PMID: 37937120; PMCID: PMC10625913.

Mills et al., International Journal of Molecular Sciences 2023 Mills ZB, Faull RLM, Kwakowsky A. Is Hormone Replacement Therapy a Risk Factor or a Therapeutic Option for Alzheimer's Disease? International Journal of Molecular Sciences. 2023 Feb 6;24(4):3205. doi: 10.3390/ijms24043205. PMID: 36834617; PMCID: PMC9964432.

US Preventive Services Task Force, JAMA 2022 US Preventive Services Task Force. Hormone Therapy for the Primary Prevention of Chronic Conditions in Postmenopausal Persons: US Preventive Services Task Force Recommendation Statement. JAMA. 2022;328(17):1740–1746. doi:10.1001/jama.2022.18625.

Langer et al., Climacteric 2017 Langer RD, Simon JA, Pines A, Lobo RA, Hodis HN, Pickar JH, Archer DF, Sarrel PM, Utian WH. Menopausal hormone therapy for primary prevention: why the USPSTF is wrong. Climacteric. 2017 Oct;20(5):402-413. doi: 10.1080/13697137.2017.1362156. Epub 2017 Aug 14. Erratum in: Climacteric. 2017 Oct;20(5):503. doi: 10.1080/13697137.2017.1368915. PMID: 28805475.

Levy & Simon, Obstetrics & Gynecology 2024 Levy B, Simon JA. A Contemporary View of Menopausal Hormone Therapy. Obstetrics & Gynecology. 2024 Jul 1;144(1):12-23. doi: 10.1097/AOG.0000000000005553. Epub 2024 Mar 14. PMID: 38484309.

Harper-Harrison et al., StatPearls 2024 Harper-Harrison G, Carlson K, Shanahan MM. Hormone Replacement Therapy. 2024 Oct 6. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2025 Jan–. PMID: 29630243.

Newson L., Body-Identical Hormones Newson L. Body identical hormones. Available at: https://www.newsonhealth.co.uk/body-identical-hormones

Canonico M, Oger E, Plu-Bureau G, et al. Hormone therapy and venous thromboembolism among postmenopausal women: impact of the route of estrogen administration and progestogens: the ESTHER study. Circulation. 2007 Feb 20;115(7):840-5. doi: 10.1161/CIRCULATIONAHA.106.642280. However, since this does not appear in your provided references, you should verify this is the correct study before using it.

Hodis & Sarrel, Climacteric 2018 Hodis HN, Sarrel PM. Menopausal hormone therapy and breast cancer: what is the evidence from randomized trials? Climacteric. 2018 Dec;21(6):521-528. doi: 10.1080/13697137.2018.1514008. Epub 2018 Oct 9. PMID: 30296850; PMCID: PMC6386596.

Johns Hopkins Medicine Johns Hopkins Medicine. Estrogen's Effects on the Female Body. https://www.hopkinsmedicine.org/health/conditions-and-diseases/estrogens-effects-on-the-female-body

El Khoudary et al., Menopause 2019 (SWAN) El Khoudary SR, Greendale G, Crawford SL, Avis NE, Brooks MM, Thurston RC, Karvonen-Gutierrez C, Waetjen LE, Matthews K. The menopause transition and women's health at midlife: a progress report from the Study of Women's Health Across the Nation (SWAN). Menopause. 2019 Oct;26(10):1213-1227. doi: 10.1097/GME.0000000000001424. PMID: 31568098; PMCID: PMC6784846.

British Menopause Society Consensus Statement 2023 British Menopause Society. BMS Consensus Statement: BMS-WHC 2020 Recommendations on HRT in Menopausal Women. Updated September 2023. https://thebms.org.uk/wp-content/uploads/2023/10/02-BMS-ConsensusStatement-BMS-WHC-2020-Recommendations-on-HRT-in-menopausal-women-SEPT2023-A.pdf