Today’s Subject: Oestrogen dominance.

I loved exploring the research behind this! There is just so much to learn. It makes me sad that nowadays so many people are suffering from these issues. We are ALWAYS so quick to blame hormones, which is completely correct, but shouldn’t we address WHY the hormones are such an issue? Well I have done he hard work for you and put together a bit of info on the matter… enjoy.

Oestrogen dominance is an umbrella term used to describe adverse symptoms associated with excess oestrogen levels compared to progesterone levels. Oestrogen levels can become high due to the use of the oral contraceptive pill, hormone replacement therapy, xenoestrogens found in the environment, and obesity.
In healthy females oestrogen levels are balanced with progesterone levels. Progesterone is produced in higher levels during the ovulatory phase of the female 28 day cycle and peak in the early luteal phase before dropping dramatically in the late luteal phase which stimulates menstruation. When oestrogen is dominant then progesterone levels can become insufficient, attribute to all sorts of disorders such as polycystic ovarian syndrome, endometriosis, infertility and cancer.

The main symptoms of oestrogen dominance is the same as what you would see with other female endocrine conditions due to the fact that most female endocrine conditions relate to oestrogen dominance. Insulin resistance, weight gain, breast tenderness, uterine fibroids, fibrocystic breast disease, premenstrual syndrome, migraines, endometriosis, ovarian cysts, breast cancer, and menstrual disturbances are just a few of the symptoms associated with oestrogen dominance.

The recent increase in oestrogen dominance in the past 100 years can be attributed to the extra oestrogen a female experience in her body over a lifetime. Females who commence menarche early, those who experience menopause later in life, as well as the use of hormone replace therapy and the oral contraceptive pill can increase the risk of developing oestrogen dominance due to the consistent levels of oestrogen, particularly oestrone circulating the body over a long period of time.

Also attributed to oestrogen dominance is the lack of time the average female is involved in reproduction and childbearing (Cunningham et al 2009). Females use to experience multiple pregnancies, as well as lactation being the main reliance for infant survival, so particular hormones such as prolactin suppress GnRH which stimulates luteinizing hormone and follicle stimulating hormone as well as reduces oestrogens and progesterone, causing ovulation suppression in order to ensure premature pregnancy did not occur.
As well as inadequate nutrition this caused extended periods of amenorrhea which would protect females from long durations of cyclic menstruation with fluctuating oestrogen levels. This would reduce the amount of oestrogen a female would experience in a lifetime and aid in protecting her from the form of oestrogen dominance we see today.

It is more common in postmenopausal females, but can affect females of any age, ethnicity and socioeconomic group. This is believed to be due to the fact that post- menopausal females no longer produce oestrogen via the ovaries, and instead oestrogen production relies on it being secreted through the adipose tissue. This type of tissue produce an enzyme called aromatase, which produces oestrogen. In healthy tissue these levels of aromatase is regulated carefully. But as females age the adipose tissue begins to increase its production of aromatase, which increase the amount of local oestrogen production.
A lack of exercise, obesity and being overweight increase the risk of developing cancer. Individuals who are overweight have an increase in adipose tissue cells, as mentioned these cells produce aromatase which stimulate the production of oestrogen. The more adipose tissue cells means more aromatase and as a result higher levels of oestrogen being produced. The risk of oestrogen dominance related disorder increases with obesity and weight gain after 18 years of age, and appears to increase with an increasing BMI in postmenopausal females (Melmed et al 2011).

Alcohol consumption is thought to have a modest association with oestrogen dominant breast cancer growth and development (Coronado et al 2011). With the increase in alcohol consumption in the past decade with the increase particularly evident among females in countries with rapid economic growth. These countries are also showing dramatic increase in oestrogen dominance (Coronado et al 2011). Alcohol is said to have an effect on oestrogen receptors and oestrogen levels by the release carcinogenic metabolites such as acetaldehyde or reactive oxygen species, as well as decreases the absorption of essential nutrients.
Increase in alcohol consumption can cause and increase in inflammatory markers and as a result, inflammation within the body.

Other causative factors for oestrogen dominance are environmental factors such as xenoestrogens or endocrine disrupting compounds (EDC). Xenoestrogens are foreign oestrogens which are widely used in industrial plastics polychlorinated biphenyl (PCB), Bisphenol A (BPA) and phthalates. These compounds apply oestrogenic effects even though differ slightly from naturally occurring oestrogens which are produced by the endocrine system. Xenoestrogens can have a serious hormone disruptive effect on females.
Xenoestrogens also include ethiny oestradiol which is used in the oral contraceptive pill and hormone replacement therapy which is derived from conjugated equine oestrogen, or pregnant horses.


Low levels of dietary fibre and high levels of saturated fat can contribute negatively to oestrogen dominance, generally through decreasing clearance of oestrogens from the bowel, and allowing excess oestrogens to be absorbed into the body instead of being eliminated. Additionally, a diet with reduced amounts of fibre and protein or deficient in vitamin B6 (Chocano-Bedoya 2011) can contribute to excess oestrogen. Stress also affect the balance of progesterone and oestrogen.

Also an overburdened or under resourced liver is a major player in oestrogen dominance, when its ability to metabolise and clear out this excess of oestrogen is let down. The liver metabolises oestrogens in its second phase of detoxification through a processes called glucuronidation and conjunction with sulfur (Melmed et al 2011). Essentially, these processes are where compounds are added to enable excretion through the bowel or kidneys.

The hormonal balance of the body is dependent upon the correct functioning of the endocrine system.  It only takes small amounts of hormone or hormone-mimicking substances to affect it. So oestrogen dominance can negatively affect the balance of the thyroid, pituitary, hypothalamus and adrenal glands, as well as the reproductive system.
Oestrogen dominance plays a role in the development of breast cancer and turning on the defect genes. Genetics play an important role in the development of oestrogen dependant cancers such as endometrial and breast cancers. If you have an immediate relative who suffers from oestrogen dominance and oestrogen dependant cancers, your risk of developing the condition increase dramatically.
Germ- line alterations in high- penetrance breast cancer vulnerability genes such as breast cancer 1, early onset (BRCA1, breast cancer 2, early onset (BRCA2), tumour protein p53, and Phosphatase and tensin homolog (PTEN) increase an individual’s risk for developing breast cancer. Gene- positive females have an 80% rick of developing breast cancer particularly those who are in the pre- menopause and post- menopausal age groups.
Oestrone is believed to cause cancer by facilitating cells proliferate. After the hormone binds to its receptors in a cell, it turns on hormone-responsive genes that promote DNA synthesis and cell proliferation. If a cell happens to have cancer-causing mutations, those cells will also proliferate and have a chance to grow into tumours or cancers. Oestrone is believed to be causative factor in endometrial, uterine and breast cancers. Around 70% of breast cancers rely on oestrogen receptors and are oestrogen dependant for their growth and development, these are known as hormone-receptor positive cancers. (Picazo, Salcedo, 2003).

When it comes to oestrogen dominance there are many factor which attribute to the disorder. An oestrogen- progesterone imbalance is to blame. When oestrogen levels are found in excess of progesterone this has an immediate effect on the female reproductive cycle. Reduced progesterone as a result of oestrogen dominance can suppress ovulation, leading to infertility as well as many other disorders associated with oestrogen dominance.
It is important that symptoms are identified early and diet and lifestyle factor are addressed in order to reverse the affects.  But the plan for balancing oestrogen must be considered according to the individual affected. A major principle of natural medicine is to remove the triggers or causes of the dysfunction wherever possible, so any plan will include ways to avoid xenoestrogens in the environment and within the body.

Aly Curd


One Comment Add yours

  1. Reblogged this on Cysters Support Club and commented:
    More info about #estrogen from…. #PCOS #Hormones #PCOSAwareness


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