How to Educate About Xenoestrogens

by Dr. Paul Hrkal ND | Follow on Twitter

Some estrogens promote cancer, while others prevent it. Do you know the difference?

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XENOESTROGENS ARE A GROUP OF ENVIRONMENTAL CHEMICALS, which mimic estrogen in the body. This family of molecules have been linked to the development and promotion of hormonally sensitive cancers.

Research is just beginning to uncover the wide-ranging effects of this class of compounds. As of 2003 there were over 160 xenoestrogens that may be involved in breast cancer development (1). Cancer types that have been well documented in literature to be related with environmental exposure include the reproductive system, breast, lung, kidney, pancreas, and brain (10).

New research is always emerging that confirms the negative impact of environmental chemicals such as dioxins, phthalates and parabens which are found in pesticides, cosmetics, cleaners and processed foods. Specifically in cancer, there is evidence the xenoestrogens play a role in all phases of cancer development including initiation, transformation, and invasion (7). For example, a number of studies have now confirmed that a chemical (a polycyclic aromatic hydrocarbon) produced during meat frying and grilling strongly increases DNA damage in breast cells and promotes breast cancer growth (14).

Two emerging concepts to consider is that:

  1. Individual differences in genes responsible for detoxification may predispose some people more than others to the harmful effects of xenoestrogens.
  2. A very concerning aspect of xenoestrogens that studies are now confirming is that exposure not only poses a health risk immediately, but also increases susceptibility to cancer and other diseases later in life (18).

There is still more research to be done to fully understand the broad health impact of xenoestrogens but the emerging evidence is frightening do to their wide spread prevalence and pervasiveness in our food products, water supply, and environment.

How to Reduce Xenoestrogen Exposure

As part of a hormonal balancing and breast cancer prevention plan, it is paramount to consider reducing the exposure to these compounds that contribute to detrimental estrogenic activity in the body. You must also support the natural detoxification pathways (i.e. phase 1 and 2 in the liver) that remove excess hormones and xenoestrogens.

Most people are inefficiently removing these compounds after they are exposed, which increases their damaging effects. Natural compounds found in vegetables and certain herbs, like milk thistle, can promote healthy detoxification and therefore indirectly balance your hormones and reduce your cancer risk.

The following are 2 simple but powerful ways to reduce your xenoestrogen exposure.

1)   Avoid plastic cups and food containers –

Some plastics contain a compound called Bisphenol A (BPA). It is leached when liquids or foods are heated, cooled or stored in plastic. BPA has been linked to promoting obesity in children, causing infertility, disrupting genes and stimulating the growth of cancer cells (17). In relation to cancer, even the amount of BPA from one plastic cup is potent enough to make chemotherapy less effective due to its estrogenic action in the body (13). Remember, cancers (especially hormone sensitive cancers such as breast cancer) growth in the presence of hormones, including xenoestrogens. The frightening part about BPA is that it can have a negative impact on fetuses causing hormones disruption in future generations (15).

  1. What to avoid: Plastic food containers (especially hard plastics), plastics water bottles, the inside lining of cans, thermal paper (receipts) and other plastics. Especially do not heat or microwave any plastics since this causes more BPA to be released.
  2. Healthy alternatives: glass or ceramic food containers, glass or stainless steel water bottles, cans that are “BPA-free,”
  3. Beware: Plastic water bottles that claim to be “BPA-free.” They are still made out of plastic so they can leach other potentially harmful compounds.

2)   Avoid Commercial cosmetics, creams and perfumes –

Topical products are notorious for containing compounds that are not only difficult to pronounce but can disrupt your hormones. Parabens and phthalates are 2 of the most detrimental compounds. They are added to many topical creams and cosmetics as preservatives and thickeners. They both have been associated with hormonal changes lower sperm count, birth defects, obesity, diabetes, thyroid irregularities and cancer growth (2, 4). Parabens are fairly easy to identify since the name usually contains the word “paraben” in it (i.e. methylparaben, ethylparaben). Phthalates are more difficult to pick out and they often are one of the molecules in the “fragrance.” Since fragrance is a secret formula, companies do not need to disclose the exact ingredients, which means that harmful compounds are most likely still in the product.

  1. What to avoid: cosmetics, lips balms, shampoo, creams, perfumes, cleaning products and detergents. To check your specific products use the these free online resources:,
  2. Healthy alternatives: look for products that do not contain the aforementioned chemicals. Use cosmetics that are paraben, sulfate, phthalates, and fragrance free. Avoid using synthetic air fresheners, perfumes and cleaners. Use vinegar, baking soda and lemon juice as household cleaners. Use essential oils and plant-based cosmetics.
  3. Beware: anti-bacterial produces such as hand soap and toothpaste. They contain the compound called Triclosan, which causes allergies, disrupts hormones, and promotes cancer growth (5). The FDA has already put out a warning, Europe has banned it but you can still buy it in Canada.

Cancer causing compounds and xenoestrogens surround us on a daily basis so we must look at every source of possible exposure in our homes and workplace. This process can be overwhelming, especially if you have never looked into some of the chemicals that may be hidden in products you have been using for many year. My advice is to start to change your environment slowly and make small, manageable changes. The good news is that there are great resources available online and with the help of you Naturopathic doctor you can make the process of eliminating harmful substances easier.

Block the effects of Xenoestrogens with Phytoestrogens

There is quite a bit of confusion about the safety and effectiveness of phytoestrogens; even among medical professionals. Phytoestrogen’s are a group of compounds found in certain plants that have an estrogen-like effect in the human body. Most people assume that this means they increase cancer growth but its important to understand that even though these compounds interact with estrogen receptors they are much weaker than human estrogen (estradiol) or most xenoestreogens (11). This means they attach to the estrogen receptor without actually activating it, therefore preventing human estrogens or other chemicals from activating the receptor.

Phytoestrogens weakly attach to estrogen receptors, without activating them, to prevent human estrogens or harmful xenoestrogens from attaching and actually reducing cancer risks. <–Tweet this

This would explain the fact that human population studies have found that soy consumption actually has a protective effect against breast cancer (12). It is worth pointing out that some animal studies have found soy supplementation promotes the growth of cancer cells, which has led to confusion and cautions regarding soy intake. However, the opposite effect has been found in humans so some experts suggest that there is a difference in the way humans and mice use phytoestrogens making animals poor test models.

To further support the safety and benefit of phytoestrogens studies have also found that soy food consumption was significantly associated with decreased risk of death and recurrence in people that were also taking tamoxifen and aromatase inhibitors (commonly used drugs in breast cancer prevention). There is no evidence that soy negatively interferes with tamoxifen or anastrozole therapy (9). While there are multiple benefits to eating non-GMO phytoestrogens such soya beans (i.e. edamame), soya products (soya sauce, tofu, tempeh etc.), hops, flaxseeds, legumes, lentils, beans and alfalfa sprouts, it is apparent that frequent dietary intake can block the negative effects of human estrogens or other xenoestrogens.

Stimulate healthy hormone metabolism and elimination

Many people know that the liver is one of the most important detoxification organs however fewer know it also is responsible for the healthy elimination of hormones as well as toxins. There are 2 phases to liver detoxification that occurs 24 hours a day. Most over-the-counter detox kits will stimulate phase 1 which prepares a toxin to be removed.

However they often do a poor job at stimulating phase 2, which is responsible for taking the molecule activated by phase 1 and safely excrete it. To eliminate harmful environmental toxins and xenoestrogens we need to support both pathways and make sure that our intestinal elimination is regular and complete. The following are simple ways to promote healthy elimination of xenoestrogens:

Stay hydrated – every cell in our body requires water to function optimally, which includes waste elimination. Water also flushes out excess waste that builds up around the cells and can impair cellular communication and elimination. Water also lubricates our bowels, which helps to prevent constipation and maintains regular intestinal elimination. The goal for most is to drink 4 large glasses of water a day (approx. 2 L).

Broccoli and broccoli sprouts – Cruciferous vegetables are perhaps the food group that has shown the most powerful anti-cancer effect (3). Theses vegetables contain a group of natural compounds (the main one being sulforaphane) that support liver detoxification (specifically phase 2) and hormone elimination pathways (4). Broccoli and broccoli sprouts are the vegetables with the highest levels of these beneficial compounds. For optimal effect they should be eaten raw (heat inactivates the enzyme) and chewed well so the enzyme that activates sulforaphane is released.

Flaxseed – Flaxseeds are well-known as a source of omega 3 and dietary fibre but now emerging research suggests that they have unique and direct anti-cancer properties such as preventing the growth of new blood vessels (8). The impact of fibre is especially important in hormonally sensitive cancers such as breast and prostate cancer because fibre can bind hormonal products excreted from the liver and ensure they are eliminated rather than be re-absorbed in the digestive tract. Ground flaxseeds provide a great source of inexpensive fibre plus hormone balancing properties.

Antioxidants – Every cell in our body uses antioxidants to protect itself from damage but the liver has the highest requirements in order to support both phases of detoxification. Its even produces large amounts of its own powerful antioxidant called glutathione. Colourful fruits and vegetables are rich in antioxidant compounds so they should be included in your daily diet. Studies have now shown that for cancer prevention variety (i.e. different colours) is even more important that quantity. Aim for at least 9 different colours of fruits and veggies daily.

Herbal support – Many people prematurely jump right to herbal detox kits without reducing their xenoestrogen exposure and modifying their diet. The basics listed above should be the first priority before finally taking a herb like milk thistle to protect the liver and stimulate glutathione production. Consult your Naturopathic doctor about which detox product is right for you. There many different options and some are better suited to certain people especially if they have hormonal imbalances. Taking a herbal formula can sometimes cause people to feel worse or get major reactions so it’s always most effective to consult your ND.

So after learning about negative effects of xenoestrogens and how avoid them, you can use a number of simple things to also promote their removal from your body. The most important things are to stay hydrated and eat healthy phytoestrogens, cruciferous vegetables, flaxseeds and colourful fruits and veggies.


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  2. Charles AK, Darbre PD. Combinations of parabens at concentrations measured in human breast tissue can increase proliferation of MCF-7 human breast cancer cells. J Appl Toxicol. 2013 May;33(5):390-8.
  3. Clarke et al. Multi-targeted prevention of cancer by sulforaphane. Cancer Lett. 2008 Oct 8;269(2):291-304.
  4. Crinnion WJ. Toxic effects of the easily avoidable phthalates and parabens. Altern Med Rev. 2010 Sep;15(3):190-6.
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  12. Kazor, Tina. The Effects of Soy Consumption on Breast Cancer Prognosis: A review of the literature. The Natural Medicine Journal. Nov 2012. Accessed on 2013-07-30.
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  14. Rohrmann et al. Dietary intake of meat and meat-derived heterocyclic aromatic amines and their correlation with DNA adducts in female breast tissue. Mutagenesis. 2009 Mar;24(2):127-32.
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  18. Wadia et al. Perinatal bisphenol A exposure increases estrogen sensitivity of the mammary gland in diverse mouse strain. EHP. 2007;115(4):592–598
About the Author
Dr. Paul Hrkal ND

Dr. Paul Hrkal is a board certified Naturopathic doctor. He is an expert in nutrition and supplemental treatments and has additional training and certification in intravenous and injection therapy. He has a special interest in brain health, neurological disorders, cancer, chronic pain and sports medicine. He also is strong advocate of integrative medicine and lectures across the country to both healthcare practitioners and public audiences. He currently practices in an integrative, multi-disciplinary pain clinic in Vaughan and Mississauga and also is a medical advisor with Advanced Orthomolecular Research.