Genetics and estrogen levels

    Estrogen is commonly associated with its role in the development of female sexual characteristics. And although it is the primary female sex hormone, it is actually produced by both sexes, performing several additional functions, including:

-Regulating bone health

-Blood flow

-Sugar and fat metabolism

    There are four different types of estrogen (E1-4), with estradiol (E2) being the most potent form in premenopausal women and men. The other forms are only present or increase during pregnancy (estriol, E3 and sterol, E4) or postmenopausal (estrone, E1).

The consequences of low estrogen production

    Estrogen influences several biological processes, which can be compromised when estrogen activity is low. This can lead to:

-Decreased insulin sensitivity: leading to high blood glucose levels. Long-term high blood glucose levels can cause damage to blood vessels and also increase the risk of cardiovascular disease and type II diabetes.

-Loss of bone density: Increased risk of osteoporosis – a condition characterized by bones that become increasingly fragile and more susceptible to fracture.

-Increased fat deposition, particularly in the visceral fat stores that surround vital organs.

-Poorer blood flow and an increased risk of plaque buildup in blood vessels. This, in turn, can increase the risk of cardiovascular disease.

The consequences of high estrogen production

    Excessively high estrogen production can also have negative health effects. This can be independently due to high estrogen levels or as a result of high levels in relation to other sex hormones (e.g. testosterone and progesterone):

Women

In premenopausal women, high levels of circulating estrogen have been associated with:

-Irregular menstrual cycles

-Weight gain

-Mood swings

Men

    High estrogen levels can create symptoms from heavy, painful periods to weight gain and fluid retention. Having excess estrogen over the long term can contribute to conditions such as fibroids and exacerbate endometriosis and fibrocystic breasts.

    In addition, high estrogen levels may be a potential risk factor for breast cancer and ovarian cancer.

In men, high estrogen levels (particularly relative to testosterone) have been associated with:

-Erectile dysfunction

-Lower fertility

-Enlarged breast tissue (gynecomastia)

Genetic factors:

CYP19A1

This gene encodes the aromatase enzyme, which converts androgens to estrogen. Variants of this gene may influence the activity of aromatase and, consequently, estrogen production.

CYP17A1

This gene encodes the 17β-HSD enzyme that converts the weak estrogen estrone (E1) to the more potent estradiol (E2). Variants of the CYP17A1 gene may influence the effectiveness of estradiol production.

Other genes

We also looked at several other genetic variants related to estrogen metabolism. For example, we looked at variants in the SHBG (sex hormone binding globulin) and estrogen receptor genes.