Let's be honest: Sometimes we know less about the female cycle than we really should, don't we? Because there's a very good chance you're also one of us who menstruates, and you surely know people who menstruate. Estrogens play something of a leading role in the female organism and the menstrual cycle. So there's plenty of reason to take a closer look at this ominous estrogen.
Our author Melanie Dell'Oro has compiled the most important and interesting facts about estrogens for you.
Contents:
Estrogen - What is it?
Estrogen is a collective term for a group of steroid hormones that play a major role in regulating the female cycle, fertility, and many other bodily functions. Although estrogen is typically associated with the female organism, it is also present in small amounts in the male body.
Estrogens are predominantly produced in the ovaries, but also in the corpus luteum, adrenal cortex, and adipose tissue, especially visceral abdominal fat.
The three main forms of estrogen
Estradiol (E2)
The most potent estrogen. It is at its highest during the reproductive phase of a woman's life and drops significantly with menopause.
Estrone (E1)
Produced primarily from adipose tissue after menopause, it replaces estradiol.
Estriol (E3)
Plays a significant role during pregnancy. It is a weaker estrogen, but has a strong local effect in certain tissues.
How and where is estrogen produced?
It is synthesized from androgens by an enzyme called aromatase.
The main production site is the follicles in the ovaries, but also the corpus luteum, adrenal cortex, and adipose tissue. The ovaries respond to the release of FSH from the pituitary gland by converting testosterone into estrogens. FSH is, in turn, released by the hormone GnRH (gonadotropin-releasing hormone), which the hypothalamus sends to the pituitary gland.
Estrogen in the menstrual cycle
Estrogen levels fluctuate cyclically. In the first phase of the cycle (follicular phase), estrogen dominates and builds up the uterine lining. In the second phase of the cycle, progesterone takes the lead.
For hormonal balance, a balanced ratio between progesterone and estradiol is important. The ideal ratio is at least 100:1 (P/E2).
Functions of estrogen
Estrogens act systemically – far beyond the reproductive system.
In the female organism, they have the following specialized functions:
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Building up the uterine lining
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Regulating cervical mucus consistency (stretchy during fertile days)
- Development of female sexual characteristics
Other functions of estrogens:
- Calcium metabolism and maintenance of bone substance
- Cardiovascular health, e.g. by lowering blood pressure
- Influence on skin health, skin aging, and wound healing
- Influence on immune cell activity
- Involvement in water balance
- Reduction of fat burning and promotion of protein synthesis
- Cholesterol reduction
- Inhibition of the appetite hormone ghrelin
- Stabilization of blood sugar through improved insulin sensitivity
- Influence on carbohydrate metabolism
Hormonal imbalance in the estrogen balance
The estrogen balance can experience both estrogen dominance and estrogen deficiency.
Estrogen dominance arises from a shift in the estrogen-progesterone balance in favor of estrogen, i.e. the ratio becomes smaller than 100. In estrogen deficiency, the absolute value of estrogen is reduced.
Direct estrogen dominance
Here, the absolute estrogen level is too high – partly due to:
- Too much adipose tissue (higher aromatase activity)
- Environmental influences such as xenoestrogens from plastic, cosmetics, food
- Slowed metabolism or disruption in estrogen recycling (see oestrobolome)
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Synthetic hormones, e.g. from the birth control pill
Indirect estrogen dominance
The estrogen level is normal or low, but progesterone is even lower, which shifts the ratio.
Important: Estrogen dominance can also occur alongside an estrogen deficiency!
Possible causes of indirect estrogen dominance:
- Stress
- Alcohol abuse, nicotine abuse
- Nutrient deficiency
Estrogen deficiency
In the case of estrogen deficiency, the body does not produce enough estrogen, so the estrogen level is lower than normal.
Important: An estrogen deficiency can still lead to estrogen dominance if the progesterone level is also too low.
Possible causes of estrogen deficiency can include:
- Under- or malnutrition
- Excessive exercise
- The birth control pill
- Physiological menopause and postmenopause, after pregnancy
- Missing ovaries or ovarian dysfunction
The Influence of the Gut: The Oestrobolome
The oestrobolome refers to certain gut bacteria involved in estrogen recycling. Dysbiosis (e.g. after antibiotics, stress, poor diet) can lead to hormonal imbalance. If there are too many of the microorganisms that recycle estrogen, estrogen dominance can occur; if there are too few, an estrogen deficiency may be supported.
Tip: Probiotics and synbiotics promote a healthy gut flora and thus a healthy estrogen balance. Especially in postmenopausal women*, it has been found that probiotics also promote the activation of phytoestrogens from food and thus contribute to a healthy estrogen balance [1].
You can read here how you can support your gut health.
Dangers of Xenoestrogens
Xenoestrogens are synthetic substances that act like estrogen in the body and disrupt the hormonal balance. They belong to the endocrine disruptors. Well-known xenoestrogens include plasticizers such as bisphenol A and phthalates. Common sources:
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Plastic products, canned food
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Cosmetics, cleaning products, textiles
- Pesticide residues
Xenoestrogens are problematic because they occur in many everyday items, and we thus consume too large quantities through skin contact, inhalation, and food intake.
Tip: How can you reduce xenoestrogens and endocrine disruptors? Read here.
Conclusion: Balance is what matters
Estrogen is essential for numerous body functions. Both deficiency and excess – especially in relation to progesterone – can lead to symptoms. A healthy lifestyle, a balanced microbiome, and the avoidance of hormone-active substances contribute decisively to hormonal balance.
