Estrogen? What is it and why should I know about it?

Estrogen is a group of hormones extremely important to the development and functioning of women's reproductive system and sexual characteristics. The hormone has a few forms and the most known are estradiol, estrone, and estriol - each playing vital roles in various physiological processes.

The hormone estrogen has several functions from controlling the menstruation cycle, development of sexual characteristics in women, maintaining bone and cardiovascular health, mood regulation and even skin health!

Regulating menstrual health and sexual characteristics

One of the most significant functions of estrogen is regulating the menstrual cycle. This hormone controls the growth of the uterine lining (endometrium) during the first part of the cycle, preparing the body for ovulation and supporting the maturation of ovarian follicles. Without adequate estrogen levels, the menstrual cycle can become irregular, impacting fertility.

Beyond reproduction, estrogen is crucial for the development of female secondary sexual characteristics, such as breast development, the widening of the hips, and the distribution of body fat. These changes are vital during puberty, shaping the female body and preparing it for reproductive functions.

Bone health

Estrogen also plays a pivotal role in maintaining bone health. It promotes the activity of osteoblasts, cells responsible for bone formation. As women age and estrogen levels decline, particularly during menopause, there is an increased risk of osteoporosis due to reduced bone density. This underscores the importance of maintaining healthy estrogen levels for long-term skeletal health.

Cardiovascular health

Cardiovascular health is another area where estrogen exerts its influence. The hormone helps maintain the flexibility of blood vessels and reduces cholesterol buildup in the arteries, thereby lowering the risk of atherosclerosis and heart disease. The protective effects of estrogen on the cardiovascular system are well-documented, highlighting its significance beyond reproductive health.

Mood

Mood regulation and cognitive function are also affected by estrogen. The hormone interacts with neurotransmitters in the brain, such as serotonin, which plays a role in mood regulation. Low estrogen levels can lead to mood swings, depression, and anxiety, particularly noticeable during the menopausal transition.

Skin health

Furthermore, estrogen contributes to skin health by promoting collagen and oil production, helping to maintain skin elasticity and moisture. This can reduce the appearance of wrinkles and keep the skin looking youthful. As estrogen levels decline with age, skin changes become more pronounced, demonstrating the hormone's impact on physical appearance.

Estrogen throughout women's lives

The importance of estrogen extends to various stages of a woman's life.
Estrogen starts to rise during puberty when a series of events initiated by the hypothalamus stimulates the ovaries to begin estrogen production. Consequently, augmented production of sex hormones causes the first menstrual period - known as menarche - as well as breast and genital growth, weight distribution, body hair, and more bodily changes.

In general, the pattern of menstrual cycles should begin to normalize within the first few years of menstruation. However, identifying abnormalities during adolescence may prevent the future development of serious health concerns.

During the reproductive years, it supports normal development and functioning of the reproductive system, enabling pregnancy - estrogen prepared the body for ovulation and conception.

At the start of the menstrual cycle, estrogen levels rise as the ovaries produce follicles, each containing an egg. When estrogen peaks, it triggers a surge in luteinizing hormone (LH), causing the mature egg to be released from the ovary (ovulation), getting ready for potential fertilization by sperm. During pregnancy, estrogen supports the placenta, aids fetal development, prepares the breasts for lactation, and regulates other crucial pregnancy hormones.

As women approach menopause, declining estrogen levels can lead to symptoms such as hot flashes, night sweats, and vaginal dryness. Additionally, the decrease in estrogen increases the risk of osteoporosis and cardiovascular disease, making it essential to monitor and manage hormone levels during this transition.

Estrogen also works in harmony with other hormones, such as progesterone and testosterone, to maintain hormonal balance. Imbalances in estrogen levels can lead to irregular menstrual cycle (making it harder to conceive), health issues, including polycystic ovary syndrome (PCOS), endometriosis, and breast cancer.


Understanding and maintaining this balance is crucial for overall health and well-being.


References

1. Estrogen: Physiology and Pharmacology. - https://onlinelibrary.wiley.com/doi/10.1016/S1526-9523(02)00233-7
2. Menopause and cognitive impairment: A narrative review of current knowledge - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8394691/
3. Production and actions of estrogens. - https://www.nejm.org/doi/full/10.1056/NEJMra000471
4. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the Women’s Health Initiative randomized controlled trial. - https://jamanetwork.com/journals/jama/fullarticle/195120