Estrogen Overload

Hormones are the chemical messengers of the body’s endocrine system. They work together in harmony to regulate many body processes, from body temperature and blood pressure to governing sexual desire and fertility. Having proper hormonal balance is something that we often don’t think about yet it is essential for good health.

For women, one of the key hormones to our physical and emotional well being is estrogen. Estrogen is not a single hormone but a group of hormones that are naturally produced in our body. In women, estrogen is produced primarily by the ovaries and to a lesser extent by the adrenal glands and in the fat cells. Estrogens play an important role in sexual and reproductive development. They are also essential for the health of our heart, blood vessels, bones, breasts, skin, hair, brain and urinary tract. During puberty, estrogen levels rise and bring on the menstrual cycle and initiate the growth of pubic and underarm hair.

Aside from the estrogen produced by our body, people today are exposed to estrogen-like compounds from drugs, the environment and even food. This estrogen overload has serious consequences for the health and disease risk facing women today.

Estrogen Replacement Therapy – The End of an Era

Since the introduction of the birth control pill in the 1960s and the promotion of hormone replacement for menopause, estrogen has been touted as a panacea for contraception, to the prevent the effects of aging, and to ward off osteoporosis, heart disease, memory loss, low libido, depression and a host of female health concerns.

The HRT panacea ended in July 2002 when one of the largest studies conducted on the benefits and risks of hormone, the Women’s Health Initiative (WHI), was halted prematurely due to serious health risks. Researchers found that use of estrogen plus progestin (Prempro™) increased the risk of breast cancer, heart disease, stroke, blood clots and urinary incontinence. In addition, the WHI Memory Study showed that estrogen plus progestin doubled the risk for developing dementia, including Alzheimer’s disease, in postmenopausal women age 65 and older.

The WHI Estrogen-Alone Study, which involved Premarin™, was stopped in February 2004, when the researchers concluded that estrogen alone increased the risk of stroke and blood clots. Women using estrogen alone also had an increased risk of urinary incontinence.

Another large epidemiologic study called the Million Women Study, has reported increased risks of breast and ovarian cancer with estrogen replacement therapy in menopausal women.

Due to the mounting health concerns associated with HRT, use of these hormones has dropped significantly over the past few years. It appears that the reduced use of HRT has already had a positive impact on breast cancer rates. In 2003, the United States reported the largest single yearly decline in the incidence of estrogen-receptor positive breast cancer among women aged 50 to 69.

The Pill and its Price

Oral contraceptives (the “Pill”) are a serious contributor to our estrogen overload. The Pill contains synthetic estrogens and progestins in varying amounts and they are prescribed not only for contraception but for the treatment of acne, premenstrual syndrome, perimenopause and hirsutism. The Pills used today contain much lower amounts of hormones compared to those used in the 1960s however they still provide about four times higher estrogen levels than would naturally be produced by a woman’s body.

While the Pill is highly effective for contraception its use comes with an alarming price. Side effects of the pill include weight gain, migraine headaches, decreased libido, breast swelling and tenderness, nausea, vomiting, vaginal dryness, spotting, skin rashes, and depression. Some of the less common but most serious concerns with the use of oral contraceptives include blood clots, increased risk of stroke, ischemic heart disease, and breast, cervical and liver cancer.

Hormonal Havoc

In her book, Sexy Hormones, Lorna Vanderhaeghe and coauthor Dr. Alvin Pettle, Gynecologist, discuss in great detail the consequences of hormone havoc. Hormonal imbalance is associated with many health conditions that plague women today, including heavy periods, fibroids, ovarian cysts, infertility, insomnia, irritability, fatigue and other problems.

Even if you don’t take oral contraceptives or HRT, you could be getting hormones in the form of xenoestrogens, which are estrogen-like compounds that are present in pesticides, foods, plastics and more (see sidebar). These chemicals are structurally similar to estrogen, so they can bind to estrogen receptors in our body and mimic, block or interfere with our hormones leading to both physical and emotional symptoms.

Food and Hormones

According to the Canadian Food Inspection Agency, sex hormones are used in beef cattle (but not in veal calves) in the form of slow-release implants (placed at base of the ear) to improve feed efficiency and growth. These implants contain any or all of the following: the natural hormones estradiol and progesterone and the synthetic hormones zeranol and trenbolone. The level of the hormones estradiol and progesterone present in meat sold to consumers is not tested as there is no way to distinguish between hormones administered and hormones naturally present.

There is a monitoring program in place to test for the synthetic hormones, and the maximum allowable amount for zeranol and trenbolone is 2 parts per billion each as established by Health Canada and posted in the Food and Drug Regulations.

Neither growth hormones nor sex hormones are used in dairy cows in Canada. In the US bovine growth hormone is used in dairy cattle however this is not approved in Canada due to health risks to the animals. And contrary to popular belief hormones are not used in poultry.

Our fish supply offers another source of estrogen-like compounds in our diet. Several reports in both Canada and the United States have revealed that salmon are contaminated with PCBs, dioxins and the pesticide dieldrin. The amount of these estrogenic and carcinogenic compounds is highest in farmed salmon however even wild salmon contain some toxins. While Health Canada has not recommended restricting consumption of farmed salmon, other health agencies, such as the American Heart Association and the American Cancer Society have issued warnings.

Environmental Estrogens


PCBs (Polychlorinated biphenyls) are chemicals used since 1929 as ingredients in industrial materials, such as sealing and caulking compounds, inks, paint additives, and to make coolants and lubricants for electrical equipment. Due to serious health hazards (cancer risk and endocrine-disrupting activity), PCBs were banned in North America in 1977 however they are still found in small quantities in all food commodities of animal origin and the environment (air and water). When wood or material containing PCBs are burned at high temperatures, the process can turn them into different substances called dioxins and furans, which are far more toxic than PCBs.


PBDEs (Polybrominated diphenyl ethers) are commercially produced substances that are used as flame retardants in a wide variety of products, such as building material, carpet underlay, curtains, and furniture foam.

PBDEs have similar properties to PCBs. They are endocrine-disrupters and are known to cause cancers in animals. They are regarded as being environmentally persistent and can accumulate in body tissues. Measurements in animals (fish, marine mammals) and humans (milk) have indicated that levels have been increasing during the past 10-15 years. According to Health Canada and Environment Canada, PBDEs are considered toxic their use is being phased out.

PFCs (perfluorinated chemicals)

PFCs are a group of chemicals widely used in a range of consumer products such as non-stick coatings on cooking pans, and stain repellent coatings on
carpets and furniture. Two of the most well-known PFCs are PFOS and PFOA.

Studies on these chemicals show that they are extremely persistent and
bioaccumulative, as well as probably cancer-causing, hormone disrupting and toxic to reproduction and development. Many countries, including Canada are working on phasing out use of these chemicals.


Pesticide intake may occur through dietary sources (food and water). Pesticides are used in agriculture to protect crops and livestock and their residues can remain after treatment. Pesticide exposure may also occur from uses on lawns, gardens, the use of insect repellents, flea and tick products on pets, or use to control pests such as ants in homes.

Organochlorine pesticides are recognized carcinogens and reproductive and developmental toxins; they are also suspected hormone disruptors and respiratory toxins.


Phthalates are chemicals used in many household cleaning products and polyvinyl chloride (PVC) plastic to improve flexibility (water bottles, baby bottles, toys), and in cosmetics (nail polish and hair dye) to bind fragrance to the product.  There are many types of phthalates including DEHP, DBP, BBP, DIDP, DINP and DNOP.

Because phthalates are not chemically bonded to PVC molecules they can be released (called “offgassing”). This increases with mechanical stress (bending, chewing) and exposure to solvents such as oils, saliva, and temperatures over 85° F.

There are extensive reports about the adverse effects of phthalates, including early puberty in girls and premature delivery. The European Union and many countries have restricted the use of phthalates in children’s toys and these chemicals were also recently banned in the state of California.

Tampons and Dioxins

Emails have circulated for years claiming that tampons are a source of dangerous chemicals called dioxins. Tampons are made from cotton, rayon or blends of both. Rayon is made from cellulose fibres derived from wood pulp which are bleached. Years ago this process created dioxins however that bleaching method is no longer used. Rayon raw material used in tampons is now produced using chlorine-free bleaching processes. Testing of currently available tampons has shown that dioxin levels are at or below the detectable limit.

Reducing your Estrogen Load

There are many things that women can do to help lessen their exposure to estrogens:

Eat organically produced food, as much as possible. Cruciferous vegetables (broccoli, kale, cabbage and cauliflower) contain compounds that aid in the removal of harmful estrogens.

Choose hormone-free meat and wild fish (not farmed).

Wash fresh produce under running water and wipe dry to help remove any surface pesticide residues, as well as dirt or bacteria.

Don’t use pesticides on your lawn, homes or on your gardens. Look for natural alternatives.

Never burn wood that has been treated or painted, since burning materials that contain PCBs can create dioxins and furans.

Minimize your use of plastics and never microwave or put hot liquids in plastic products. Use glass, stainless steel, or ceramic dishes.

Boost your intake of fibre (through organic whole grains, vegetables and fruits) or take a fibre supplement. Fibre aids in the removal of toxins.

Drink lots of purified water.

Reduce your stress. Chronic stress can lead to adrenal exhaustion, which can impact hormonal balance.

Regular exercise promotes good hormone balance. Aim for one hour of moderate intensity activity every day.

For birth control, use the rhythm method (avoiding intercourse during ovulation) and condoms which also protect against STDs.

Take care of your liver—it is your key detoxifying organ and is also responsible for producing cholesterol, which is the starting material for all sex hormones. Minimize alcohol use and taking drugs, such as acetaminophen which are hard on the liver.

Consider supplements that aid detoxification of estrogens such as indole-3 carbinol, calcium D-glucarate, curcumin, milk thistle and green tea.


Telephone conversation and email correspondence February 28 and 29th with
Howard J. Scrimgeour, D.V.M., Program Specialist – Chemical Residues, Meat Programs Division, Canadian Food Inspection Agency. (519) 826-2908

The Endocrine Society and The Hormone Foundation

Reeves GK, Beral V, Green J, Gathani T, Bull D. Hormonal therapy for menopause and breast cancer risk by histological type: A cohort study and meta-analysis. Lancet Oncology 2006; 7:910–918.

Rossouw JE, Anderson GL, Prentice RL, et al. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: Principal results from the Women’s Health Initiative randomized controlled trial. Journal of the American Medical Association 2002; 288(3):321–333.

Shumaker SA, Legault C, Rapp SR, et al. Estrogen plus progestin and the incidence of dementia and mild cognitive impairment in postmenopausal women: The Women’s Health Initiative Memory Study: A randomized controlled trial. Journal of the American Medical Association 2003; 289(20):2651–2662.

Chlebowski RT, Hendrix SL, Langer RD, et al. Influence of estrogen plus progestin on breast cancer and mammography in healthy postmenopausal women: The Women’s Health Initiative randomized trial. Journal of the American Medical Association 2003; 289(24):3243–3253.

Stefanick ML, Anderson GL, Margolis KL, et al. Effects of conjugated equine estrogens on breast cancer and mammography screening in postmenopausal women with hysterectomy. Journal of the American Medical Association 2006; 295(14):1647–1657.

Grady D, Gebretsadik T, Kerlikowske K, Ernster V, Petitti D. Hormone replacement therapy and endometrial cancer risk: A meta-analysis. Obstetrics and Gynecology 1995; 85(2):304–313.

Lacey JV Jr., Mink PJ, Lubin JH, et al. Menopausal hormone replacement therapy and risk of ovarian cancer. Journal of the American Medical Association 2002; 288(3):334–341.

Rodriguez C, Patel AV, Calle EE, Jacob EJ, Thun MJ. Estrogen replacement therapy and ovarian cancer mortality in a large prospective study of US women. Journal of the American Medical Association 2001; 285(11):1460–1465.

Anne Platt McGinn, Worldwatch Institute, Why Poison Ourselves? A Precautionary Approach to Synthetic Chemicals, Worldwatch Paper 153, ISBN: 1-878071-55-6, November 2000.

U.S. Centers for Disease Control and Prevention, Third National Report on Human Exposure to Environmental Chemicals, July 2005.

BC Blount et al, “Levels of Seven Urinary Phthalate Metabolites in a Human Reference Population,” Environmental Health Perspectives 108: 979-982 (2000).

Environmental Defense, Toxic Nation report available at:

Canadian Cancer Society, Tampons and Cancer:,2704,3172_369449__langId-en,00.html

Gillum LA, Mamidipudi SK and Johnston SC. Ischemic Stroke with Oral Contraceptives: A Meta-Analysis. JAMA. 2000;284:72-78.