The American Cancer Society estimates that more than 211,000 women developed invasive breast cancer in 2005. Even a small percentage of men, while genetically at low risk for the disease, develop it. Science, however, has yet to identify a clear and distinct cause.

Dr. Philippa Darbre, a senior lecturer in oncology at the University of Reading’s School of Biological Sciences in England, published a report titled “Environmental Oestrogens, Cosmetics and Breast Cancer” in the March issue of Best Practice & Research: Clinical Endocrinology & Metabolism (Vol. 20, No. 1, 2006). Her article explored a possible connection between breast cancer and the daily application of cosmetics that contain estrogenic chemicals. Other factors considered were environmental estrogens that enter the body through food, water and air.

Epidemiological studies have shown that 90% of breast cancers are environmental in origin, Dr. Darbre notes, and the major influence is constant exposure to estrogen over a lifetime.

In light of this, we must consider our continuous exposure to the hundreds, if not thousands, of chemicals that bombard us on a daily basis. The chemicals that find their way to the breast’s fatty tissue are potential endocrine disruptors that interfere with our body’s normal functions. They can keep estrogen levels continually high, well above the norm.

Women are exposed to the highest levels of estrogens between puberty and menopause, and levels vary during one’s regular monthly cycle. But when breast tissue is consistently exposed to high levels, problems can arise.

We must therefore understand how environmental estrogenic chemicals disrupt the endocrine system—a network of glands and hormones that regulate many bodily functions. Endocrine glands produce hormones that are released into the bloodstream, serving as chemical messengers that control growth, metabolism, sexual development, and egg and sperm development, among other functions. These glands include the hypothalamus, pituitary gland, pineal gland, thyroid, parathyroid, pancreas, adrenal glands, ovaries and testes.

It’s important for women to take health matters into their own hands, educating themselves about environmental estrogens and limiting their exposure. The following table delineates the endocrine-disrupting chemicals found in cosmetics and beauty products. Many are used in multiple products, so it’s important to read product labels carefully.

 

Chemical Ingredient

Function and Product Categories

Health Information and Risks

Parabens

Synthetic preservative used in cosmetics, food and pharmaceuticals

Found in human breast, cancer hazard, reproductive developmental toxicity, illegal ingredient in EU

Phthalates

Plasticizer found in multiple products, including nail polish and fragrances

Cancer hazard, reproductive developmental toxicity, illegal ingredient in EU

Triclosan

Antiperspirant/deodorant preservative, facial cleanser, liquid hand soap, facial moisturizer, acne treatment

Found in human breast milk, cancer hazard, reproductive developmental toxicity, illegal ingredient in EU

Sunscreens

Absorb ultraviolet light

Penetration of human skin, mimics estrogen activity

Coal tar

Shampoo, dandruff scalp treatment, anti-itch rash cream

Cancer hazard, reproductive developmental toxicity, illegal ingredient in EU

Hydroquinone

Skin fader/lightener, hair bleach and color, facial moisturizer/treatment, powder

Cancer hazard, reproductive developmental toxicity, illegal ingredient in EU

8-prenylnaringenin

Breast enhancers

Mimics estrogen activity

Miroestrol/deoxymiroestrol

Breast enhancers

Mimics estrogen activity

Cyclosiloxanes

Hair conditioner

Mimics estrogen activity

Aluminum salts

Antiperspirant

Measured in blood following application to human underarm, endocrine disruptor

Formaldehyde

Nail treatment, flame-retardant products

Cancer hazard, reproductive developmental toxicity, illegal ingredient in EU

Toluene

Nail polish and treatments

Cancer hazard, reproductive developmental toxicity, illegal ingredient in EU