Oestrogen Dominance: Avoid It And Reduce Your Risk Of Cancer

Oestrogen is a perfectly normal, health-promoting hormone, but in excess it can contribute to a host of problems..

There are many ways to become oestrogen dominant, and many ways to avoid it. Let’s look at these in turn and see what you can do to keep these health-promoting hormones in balance.

Environmental Oestrogens

Although it is impossible to quantify, there is little doubt that our exposure to some 70,000 man-made hormone-disrupting chemicals is part of the reason for the explosion in breast and prostate cancer. Many of these compounds, from the now banned pesticide DDT and the most insidious of all industrial pollutants, PCB’s, mimic oestrogen by virtue of having a similar structure involving something called a ‘phenol’ ring. PCB, for example, stands for poly-chlorinated biphenyl. Many of these phenolic compounds are like poison to the body, and can sometimes latch onto the oestrogen receptor sites on cells triggering abnormal growth messages.

When Israel, which used to have one of highest incidences of breast cancer, banned DDT, BHC and Lindane – all hormone-disrupting chemicals – the incidence of breast cancer dropped by 8 per cent. So, what can you do to minimise your exposure? Avoid the most harmful sources and switch to alternative foods, toiletries, household products and packaging.

The Key Chemicals to Avoid are:

• Pesticides and herbicides – DDT, DDE, endosulfan, methoxychlor, heptachlor, toxaphene, dieldrin, lindane and atrazine
• Plastic compounds – alkyphenols, such as nonylphenol and octylphenol; biphenolic compounds, such as bisphenol A; and phthalates
• Industrial compounds – some PCBs (polychlorinated biphenyls), dioxin, plus those listed for plastics • Cosmetics – parabens
• Foods – butylated hydroxyanisole (BHA, an antioxidant)

Check your bathroom products, washing up liquid, dishwasher and washer detergents for the chemicals listed above. If you find them included, switch to a different brand. These very flexible plastics may contain the above chemicals.

  • Buy and eat organic fruits and vegetables as much as possible.
  • Avoid fatty foods, like cheese, wrapped in cling-film.
  • Reduce your intake of animal fats (meat and milk) which are more likely to accumulate hormone-disrupting chemicals.
  • Choose organic if you can.

HRT and the Pill

Against this background of potential over-exposure to oestrogen-like chemicals, taking the birth control pill or HRT can encourage too many oestrogen growth messages. The birth control pill is a greater risk factor the higher the dose, the longer it’s taken, but especially when it is taken by girls under the age of 20, when the breasts are still developing. Breast cells are particularly vulnerable at this stage and the evidence suggests that early pill use can as much as triple a girl’s risk of breast cancer later in life.

Hormone Replacement Therapy (HRT) takes two forms. Oestrogen only (usually oestradiol) and oestrogen plus progestins. Oestrogen-only HRT is well known to increase risk for uterine as well as breast cancer.

Progesterone protects against uterine cancer. Progestins are man-made molecules that behave somewhat like progesterone in that they too protect the uterus. The combined oestrogen + progestin HRT is therefore given to women with wombs, while oestrogen only is given to women who have had their womb removed in a hysterectomy. Unlike progesterone, which reduces cancer risk, these synthetic progestins have now been repeatedly linked to increasing risk of breast and possibly ovarian cancer. As the studies below show, the risk is greater the longer you’ve been on HRT. As every new breast cancer HRT scare hits the headlines, more and more women are turning away from HRT, which is taken either to lessen menopausal symptoms or to reduce risk of osteoporosis.


• HRT for longer than five years doubles the risk of breast cancer. The risk is higher if oestrogen plus progestins are given. Reference: L. Bergvist et al, New England Journal of Medicine, vol. 32 (1989), pp. 293-297
• HRT for five or more years increases breast cancer risk by 71%. The risk is higher if oestrogen plus progestins is given. Reference: G. Colditz et al, New England Journal of Medicine, vol. 332 (1995), pp. 1589-93.
• Ovarian cancer risk is 72% higher on oestrogen HRT. Reference: C. Rodriguez et al, American Journal of Epidemiology, vol. 141, no. 9 (1995), pp. 828-835.
• An Oxford University review of all research up to 1997 concluded that “HRT raises the risk of breast cancer by 25%”.
• Combined oestrogen and progestin HRT for five years increases risk of invasive breast cancer by 26%, strokes by 41% and heart disease by 22%. Reference: Women’s Health Initiative, Journal of American Medical Association, vol. 288, no. 3 (2002), pp. 321-33.

Liver Problems

Hormones are very short lived in the body because the liver breaks them down. This is how the body prevents excessive levels of oestrogen accumulating. However, if a person’s ability to detoxify is under par, oestrogens can keep circulating the body. This is probably why drinking more than one unit of alcohol a day increases risk for breast cancer. If the liver’s detox capacity is being used up by alcohol, oestrogens are likely to be in circulation for longer.

The better your diet and intake of antioxidant nutrients, the more efficient your liver will be at clearing excess oestrogen.
– Don’t Drink More than 4 Glasses of Wine a Week
– Eat at least five servings of fresh fruit and vegetables a day
– Supplement an all-round multivitamin and mineral, plus an antioxidant supplement including glutathione or n-acetyl cysteine.

Sugar, Saturated Fat and Stress

The best diet for preventing breast cancer is both clear and complex. It’s clear because those people who eat lots of fruit and vegetables, beans or lentils, have very little high-fat, high-sugar junk food, do exercise and neither smoke, nor are overweight have by far the lowest risk. It’s complex because unravelling why these foods and lifestyle habits lead to breast cancer is complex. It goes something like this. Hormones are fat-like and a high-fat diet is more likely to lead to high hormone levels. Some oestrogen is made in fat cells, so obese people make more. Eating sugary foods leads to not only obesity, but also ‘insulin resistance’.

Insulin is the hormone that carries sugar digested from dietary carbohydrates into our body cells where it can be converted to energy. Having too much sugar means that our cells become less responsive to insulin, so our energy levels drop. This leads to carbohydrate craving. Most sugary snacks are also high in fat and the excess calories mean more fat and more hormones. On top of all this, high sugar and stimulant consumers often end up more stressed as they lose the ability to keep their energy levels even. Stress releases the hormone cortisol and this also increases breast cancer risk by suppressing the body’s own defence – the immune system.

Fats damaged by frying are the worst because they deliver millions of oxidants (cancer-causing chemicals) into the body. So do crispy, burnt foods, which contain acrylamides. So chips are bad news. Not all fats, however, are bad for you.

The Essential omega 3 and 6 fats, found in nuts, seeds, fish and their oils – provided not heated, damaged or fried – confer protection. Essential fats can reduce the symptoms of PMS and the menopause as well as allergies, arthritis, eczema, depression and infections. They are also needed to make the receptor sites – the ‘ears’ of body cells – to receive hormonal messages, so a good intake of essential fats is vital for maintaining hormonal balance. Symptoms of deficiency are dry skin or eczema, dandruff, frequent thirst, PMS or breast tenderness and inflammatory problems such as arthritis.

– Avoid sugar and daily caffeinated drinks
– Reduce your intake of saturated fat by eating fish instead of meat, and choosing lean meat
– Don’t smoke
– Keep fit, not fat

Fruits, Vegetables, Seeds and Pulses

Fruits and vegetables are the major source of cancer-protective antioxidants so the higher your fruit and vegetable intake, the lower your risk. Seeds are the best source of vitamin E, a fat-based antioxidant that protects you from the harmful effects of damaged fats. The other food that consistently lowers risk is the pulse family, which includes beans, peas and lentils. Much of the attention has focussed on soya due to its high levels of ‘phytoestrogens’ (a naturally-occurring plant-based oestrogen), however other pulses, for example chickpeas, have high levels of phytoestrogens too.

Since we’ve been trying to lower overall oestrogen load why would you want plant-based oestrogen? Unlike other oestrogen-like chemicals – from DDT to lindane, or oestrogen itself – these plant oestrogens are very, very weak. They still lock into the oestrogen receptors but, far from sending a strong ‘growth message’ they may lessen growth messages by blocking the receptors from receiving more powerful and disruptive oestrogen messages. Communities who eat a soya-based diet have consistently lower breast and prostate cancer risk.

A recent study from Singapore found a direct reduction in risk of early indicators of breast cancers and increased soy consumption, mainly as tofu, a curd made from the soya bean, that is one of the richest source of isoflavones. These are substances which are also known to reduce menopausal symptoms. Before you go overboard on soya, a word of caution: non-fermented soya products can have very high levels of phytates and genestein (natural substances which block uptake of nutrients), both of which may not be good news. Fermented soya products, such as miso, tempeh and natto and some forms of tofu are much better for you. Even so, I recommend you only have the equivalent of that eaten by those who have low cancer risk, which is about 30 grams, or an ounce a day. This provides a daily dose of about 20 to 30mg of isoflavones. Supplements of isoflavones from fermented soya are another option.

– Eat at least five servings of fresh fruit or vegetables every day
– Eat essential fats every day
– a heaped tablespoon of seeds, or a tablespoon of oil a day, plus fish instead of meat
– Increase Phytoestrogens
– eat some beans, lentils, chickpeas, or soya produce (miso, tempeh, natto or tofu)


If a woman doesn’t ovulate, which is quite common after the age of 35 (and, of course, after the menopause) no progesterone is produced. This is because progesterone is produced in the sack that contains the ovum only if the ovum is released. Because of this, women are more likely to suffer from oestrogen dominance.

References and Further Reading:

1. G. R. Heninger , ‘Serotonin, sex, psychiatric illness’, Proc Natl Academic Science, vol. 94, no. 4 (1997), pp. 823-4.

2. B. Nemets et al, ‘Addition of Omega-3 Fatty Acid to Maintenance Medication Treatment for Recurrent Unipolar Depressive Disorder’, American Journal of Psychiatry, vol. 159 (2002), pp. 477-479.

3. R. K. Chandra, ‘Effect of vitamin and trace-element supplementation on immune responses and infection in elderly subjects’ Lancet, vol. 341, no. 8840 (January 1993), pp. 306-7.

4. M. Van Straten and P. Josling, ‘Preventing the Common Cold with a Vitamin C supplement’, Advances in Therapy, vol. 19, no. 3 (May/June 2002), pp. 151-157.

5. British Journal of Phytotherapy, vol. 2, p2 (1991).

6. Roesler, J et al., ‘Application of purified polysaccharides from cell cultures of the plant Echinacea purpurea to mice mediates protection against systemic infections with Listeria monocytogenes and Candida albicans’, Int. J. Immunopharmac., vol 13, pp 27-37 (1991).

7. Erhard, M. et al., ‘Effect of Echinacea, Aconitum, Lachesis and Apis extracts, and their combinations on phagocytosis of human granulocytes’, Phytother. Res., vol 8, pp 14-17 (1994).

8. Z. Zakay-Jones et al, ‘Inhibition of several strains of influenza virus in vitro and reduction of symptoms by an elderberry extract (Sambucus nigra L.) during an outbreak of influenza B panama’, Journal of Alternative and Complementary Medicine, vol. 1 (1995), pp. 361-9. Food, Nutrition and the Prevention of Cancer: A Global Perspective’, World Cancer Research Fund & American Institute for Cancer Research, 1997.