Understanding Estrogen’s Effects on the Body

Estrogen is a sex hormone produced in both the male and female human body. It impacts more areas of health than you may realize, though the focus here is on estrogen in female bodies.

For people assigned female at birth, the role of estrogen goes beyond fertility and sex-related functions. It includes protective effects on mood and mental health, bone strength, and even heart health. Estrogen also may be linked to disease, as with breast cancer risk.

This article will explore the forms of estrogen produced in the body and the hormone's role in the overall health of cisgender women, beyond pregnancy and the menstrual cycle.

Different Types of Estrogen

Hormones are chemicals produced by your body that act as messengers to help control and coordinate how your body works and responds to your environment. Your body produces three different types of estrogen.

During your lifetime, the amounts of each of these different estrogens will change.

Estrone (E1)

Estrone is the second most common type of estrogen produced by your body during your childbearing years. It also has a weaker effect than estradiol on your body's estrogen-specific hormone receptors.

Estrone is primarily made from another type of sex hormone in your body called androgens. A special biochemical process called aromatization changes the androgen into estrone. This process happens mostly in your body's adipose tissue or fat cells and in your muscles.

Only a small amount of estrone is produced by your ovaries. In menopause, when your ovaries stop producing hormones, estrone is the only type of estrogen your body continues to produce.

Estradiol (E2)

Estradiol is the major estrogen in your body during your childbearing years. This is the time from just before your first period until your last period or menopause. During this time, you have more estradiol in your bloodstream than you do other types of estrogen. Estradiol also has the strongest effect on your body's estrogen-specific hormone receptors.

Estradiol is produced mainly in your ovaries, and the amount they produce varies over the course of your monthly menstrual cycle. A small amount of estradiol is converted from another type of estrogen called estrone.

Estriol (E3)

Estriol is typically known as the estrogen of pregnancy. It is present only in a very small (almost undetectable) amount in your bloodstream when you are not pregnant. Of all the types of estrogen, it has the weakest effect on your body's estrogen receptors.

Although all types of estrogen levels increase when you are pregnant, estriol levels increase the most. That's thanks to the placenta.

Estrogen plays many important roles in pregnancy, including promotion of fetal growth and development. It also helps to prepare your breasts for lactation.

What Does Estrogen Do in the Body?

As a hormone, estrogen (mostly estradiol) acts on the parts of your body that have estrogen-specific hormone receptors. Estrogen is involved with numerous important functions throughout your body.

• Sexual Development: Estrogen is responsible for the growth and continued development of your reproductive anatomy including your vagina and uterus. It also is responsible for the development of your breasts and the growth of your pubic and armpit hair during puberty. Together, these changes signal the upcoming arrival of your first menstrual period, which marks the beginning of your childbearing years.
• Menstrual Cycle: The underlying purpose of your menstrual cycle is to prepare your body for pregnancy. When you don't get pregnant during a monthly cycle, your uterus sheds its lining and you get your period. Estrogen is the hormone responsible for building up the lining of your uterus every month in preparation for pregnancy.
• Bone Development and Health: Estrogen plays an important role in the healthy development of your bones. It also regulates bone turnover in your adult bones and protects against bone loss. During menopause, when estrogen levels fall, women can experience a significant increase in bone loss because the protective effect of estrogen is gone. This dramatic increase in bone loss can lead to osteoporosis, which puts you at greater risk for a hip fracture.
• Heart Health: Estrogen helps protect against heart disease. It helps to keep your blood vessels healthy, limit inflammation, and control cholesterol levels. The positive effect of estrogen on heart disease is significant in premenopausal women. In menopause, when the protective effect of estrogen is gone, there is a steady increase in heart disease in women. In fact, complications of heart disease are the leading cause of death in women in the United States.
• Mood Management: Estrogen affects how your brain structures are connected, the way your brain cells communicate, and even the shape of your brain. It has a very strong effect on serotonin, a mood-balancing chemical produced with the help of estrogen. It is thought that a low estrogen-related drop in serotonin production contributes to postpartum and menopausal depression.

Estrogen Levels

Changes in your estrogen levels can be associated with certain medical conditions or other lifestyle or health factors, like strict dieting or an older age. These changes lead to either low or high levels of estrogen. Neither high nor low levels of estrogen are better than maintaining a balanced level.

Low Estrogen

In women, estrogen levels are highest in their 20s and then drop by 50% by age 50. Lower estrogen levels also can be caused by other conditions, including thyroid or chronic kidney disease. Nutrition, exercise, and eating disorders may also be factors.

Symptoms of low estrogen levels include:

• Hot flashes and night sweats
• Insomnia
• Headaches
• Depression 
• Weight gain
• Infertility
• Sexual function problems, like painful sex due to a decrease in vaginal lubrication

Low estrogen also can lead to osteoporosis, bone damage that can lead to fracture.

High Estrogen

High estrogen levels can lead to health issues. High levels are common in people who have a condition called estrogen dominance. Among other things, it is associated with obesity, stress, and health conditions including polycystic ovary syndrome (PCOS).

Symptoms that occur when you have high estrogen levels include:

• Bloating and weight gain
• Breast tenderness
• Period changes, including premenstrual syndrome (PMS) symptoms
• Mood swings and memory problems
• Insomnia
• Sexual dysfunction

In men, high estrogen levels can lead to infertility, erectile dysfunction, and breast enlargement known as gynecomastia.

High estrogen levels are associated with a risk of cervical and breast cancer, as well as high blood pressure and blood clots.

How to Increase Estrogen

There are several ways for people to increase estrogen levels. Be sure to discuss your estrogen level with a healthcare provider, though, to make sure an increase is truly needed and the best way to achieve it.

Hormone Replacement Therapy

In some cases, it's possible to take estrogen supplements. Hormone replacement therapy (HRT) is quite common for women at or near menopause (when periods stop) and those who have had surgery to remove the uterus and ovaries (hysterectomy).

Diet and Foods

A form of estrogen produced in plants is called phytoestrogen. These phytoestrogens include nutrients called isoflavones, stilbene, coumestan, and lignans, found in foods you can add to your diet. Foods with phytoestrogen include:

• Fruits like apples and grapes
• Vegetables such as sweet potatoes and spinach
• Chickpeas, lentils, and other legumes
• Whole grains, including barley and brown rice
  

Supplements

Phytoestrogen supplements are available, apart from food sources. So is vitamin D, which plays a role in the production of reproductive hormones in both men and women. More research is needed to better understand if vitamin D supplements can boost estrogen.

Summary

Estrogen plays an important role in human health, notably in people assigned female at birth. Your estrogen levels, and the types of estrogen your body produces, will change over time.

Both high and low estrogen levels can cause symptoms and lead to significant health impacts. You can make diet and other lifestyle changes to improve your estrogen levels, but be sure to discuss your options with your healthcare provider. They may recommend other treatments.