The Biological Functions of Estrogen: Understanding It’s Role in Perimenopause and Beyond

Estrogen is indeed most commonly associated with reproductive health, but its effects extend well beyond fertility and menstruation.

It’s a hormone that touches nearly every part of the body, influencing the function and health of over 200 different tissues. Estrogen can be likened to the proverbial fountain of youth.

Let’s explore some of the key areas where estrogen plays a pivotal role:

1. Brain Function and Mood Regulation

Estrogen’s role in brain health through perimenopause and beyond

Estrogen has a profound impact on the brain, influencing cognitive function, memory, and mood. It plays a protective role in neural health by promoting communication between neurons and stimulating the production of neurotransmitters like serotonin, dopamine, and acetylcholine, which are critical for mood regulation and cognitive function. A decline in estrogen during perimenopause and menopause is linked to mood disturbances such as depression and anxiety, as well as cognitive issues like memory lapses and difficulty concentrating.

Key functions:

• Enhances synaptic plasticity (the brain’s ability to adapt and learn)
• Supports production and regulation of mood-related neurotransmitters.
• May protect against neurodegenerative diseases such as Alzheimer’s by reducing oxidative stress and inflammation in the brain [1].

2. Bone Strength

Estrogen and bone strength in perimenopause

Estrogen is essential for maintaining bone density by regulating the balance between bone resorption (breakdown) and bone formation. It inhibits osteoclasts, the cells responsible for bone resorption, thereby reducing the loss of bone tissue. As estrogen levels drop in menopause, bone density can decline, increasing the risk of osteoporosis and fractures. Postmenopausal women are particularly vulnerable to bone loss because the protective effects of estrogen are diminished [2].

Key functions:

• Inhibits bone resorption and enhances calcium absorption.
• Reduces the risk of osteoporosis by maintaining bone mineral density.
• Supports skeletal strength and structure, helping prevent fractures [3].

3. Cardiovascular Health

Heart health in perimenopause

Estrogen has significant protective effects on the cardiovascular system. It promotes the dilation of blood vessels and maintains healthy blood pressure by increasing the production of nitric oxide, a vasodilator. Estrogen also helps regulate cholesterol levels by increasing HDL (the “good” cholesterol) and reducing LDL (the “bad” cholesterol). This balance supports arterial health and reduces the risk of atherosclerosis, a key factor in heart attacks and strokes. When estrogen levels fall during menopause, the risk of cardiovascular diseases rises, contributing to a higher incidence of heart disease in postmenopausal women [4].

Key functions:

• Promotes vascular health by maintaining flexible, dilated blood vessels.
• Improves cholesterol profile, reducing the risk of plaque buildup in arteries.
• Reduces overall cardiovascular risk factors such as hypertension and atherosclerosis.

4. Skin and Hair Health

Estrogen contributes to the maintenance of skin hydration, elasticity, and collagen production. As estrogen levels decline, particularly during menopause, women often notice changes such as dry skin, wrinkles, thinning skin, and hair loss. Estrogen’s role in maintaining collagen and moisture helps keep skin looking youthful and supple. It also influences the growth cycle of hair, and a drop in estrogen can lead to hair thinning or loss.

Key functions:

• Promotes collagen production, enhancing skin elasticity and strength.
• Maintains skin hydration by increasing hyaluronic acid.
• Supports healthy hair growth by extending the growth phase of hair follicles.

5. Metabolism and Weight Regulation

Perimenopause, estrogen and weight maintenance

Estrogen helps regulate fat distribution, metabolism, and insulin sensitivity. It influences where fat is stored in the body — typically around the hips and thighs in women of reproductive age. When estrogen declines, fat distribution shifts more towards the abdomen, which is linked to an increased risk of metabolic diseases such as type 2 diabetes and cardiovascular disease. Estrogen also helps maintain a healthy balance of insulin, playing a role in glucose metabolism and energy production.

Key functions:

• Influences body fat distribution and promotes fat storage in lower-risk areas like the hips and thighs.
• Enhances insulin sensitivity and glucose metabolism.
• Reduces the risk of metabolic syndrome and associated conditions like type 2 diabetes.

6. Immune System Modulation

Estrogen plays a modulatory role in the immune system. It enhances the body’s ability to fight off infections and may help reduce inflammation. However, estrogen also influences autoimmune diseases, which are more common in women, particularly during reproductive years when estrogen levels are higher. After menopause, shifts in immune function occur as estrogen levels drop, potentially affecting the body’s ability to respond to infections and inflammatory conditions.

Key functions:

• Enhances immune response by increasing the activity of immune cells.
• Modulates inflammation, helping to balance the body’s immune reactions.
• Influences the prevalence of autoimmune conditions.

7. Urogenital Health

Estrogen maintains the health of the vaginal lining, the bladder, and the urethra. It promotes blood flow to the pelvic region, keeping tissues elastic, moisturized, and resilient. A drop in estrogen can lead to vaginal dryness, atrophy, and discomfort, often contributing to painful intercourse (dyspareunia) and urinary symptoms such as increased urgency, frequency, or incontinence.

Key functions:

• Maintains vaginal lubrication and tissue elasticity.
• Supports the integrity of the urinary tract, reducing the risk of urinary tract infections (UTIs).
• Helps prevent atrophy of the vaginal and urethral tissues.

Conclusion

Estrogen’s influence is wide-ranging, affecting systems throughout the body, from the brain to bones, skin to cardiovascular health. Understanding estrogen’s roles outside of reproduction highlights its significance in overall well-being, especially for women navigating perimenopause and menopause. When estrogen levels decline, it is important to adopt strategies — whether through lifestyle modifications, hormone replacement therapy, or a combination of approaches — to mitigate the health risks associated with estrogen loss and support long-term vitality.

Let me know if you would like to explore how different therapies or lifestyle changes can support estrogen function during menopause. Book a consultation.

References

1. Shao H, et al. Hormone therapy and Alzheimer disease dementia: New findings from the Cache County Study. Neurology. 2012;79(18):1846–1852. DOI: 10.1212/WNL.0b013e318271f823
2. Khalid AB, Krum SA. Estrogen receptors alpha and beta in bone. Bone. 2016;87:130–135. doi: 10.1016/j.bone.2016.03.016
3. Cauley JA, et al. Effects of estrogen plus progestin on risk of fracture and bone mineral density: the Women’s Health Initiative randomized trial. JAMA. 2003;290(13):1729–1738. DOI: 10.1001/jama.290.13.1729
4. Mendelsohn ME, Karas RH. The protective effects of estrogen on the cardiovascular system. N Engl J Med. 1999;340(23):1801–1811. DOI: 10.1056/NEJM199906103402306