Parabens - Their Safety is in Question

Written by Jill Dunn - MHSc Complementary Medicine, Registered Naturopath, Registered Medical Herbalist, Registered Nurse (Non-practising)

A recent publication in a scientific journal has suggested a link between a class of chemicals called parabens and breast cancer.1 Parabens are commonly used preservatives found in cosmetics, pharmaceutical and industrial products and some foods. They prevent the growth of yeasts, molds and bacteria and preserve the shelf life of a range of everyday products including skin moisturisers, shampoos, conditioners, soaps, toothpastes, antiperspirants and deodorants, sunscreens, make-up and pharmaceutical products that include topical skin preparations. They can also be found in foods such as salad dressings, spiced sauces, soft drinks, fruit juices, processed vegetables, jams and jellies and baked goods.

Parabens were first introduced in the 1930's and up until recent talk of their possible link with breast cancer and diminishing testosterone levels, have always been considered safe. Recent laboratory and animal studies have shown that parabens have oestrogenic activity and were able to bind to oestrogen receptors on body cells in both animals and humans. Parabens have also been isolated from breast tumours in human tissue, and several animal studies have found that exposure to parabens adversely affected the secretion of testosterone and the function of the male reproductive system.2

There is increasing acceptance that environmental pollution (particularly oestrogen-like chemicals) is probably associated with adverse trends in reproductive health such as endometriosis, polycystic ovaries, breast cancer, semen quality, prostate and testicular cancer. We know that only five per cent of breast cancer is genetic, the majority of cases are believed to be due to lifestyle and environmental factors, with oestrogen considered the major factor3. Organochlorine agricultural chemicals used in our food production and polychlorinated biphenyls found in fat tissue of fish and animals as a result of environmental pollution, are also known to have oestrogenic activity and have been detected in human breast tissue3. Endocrine disruption, particularly exposure to oestrogenic chemicals have produced adverse effects in water-living animals, although at present there is no evidence to suggest human health has been adversely affected, mainly because the appropriate research has not been carried out.

So exactly what are parabens?

The term “paraben” is an abbreviation for para-hydroxybenzoic acid and there are five widely marketed types – methylparaben, ethylparaben, propylparaben, butylparaben and benzylparaben each having different solubility and antimicrobial activity. Although the potency of these oestrogenic compounds is relatively low, exposure occurs daily. In the U.S. the average total paraben exposure for an individual has been estimated to be approximately 76 mg per day (1.3 mg/kg/per day for a person weighing 70 kg)2. The greatest exposure comes from cosmetics and personal care products (such as deodorants, moisturisers, shampoos, conditioners, sunscreens, toothpastes) which have been estimated to provide 50 mg per day, medications supply 25 mg per day (ointments, creams, eye drops) and food (mayonnaise, salad dressings, sauces) provides about 1 mg per day. When cosmetics and skin care products containing parabens are applied to the skin, enzymes within the skin and in the fat below break these chemicals down into parahydroxybenzoic acid and other fragments. Parabens are readily absorbed through the skin as well as orally, and were once thought to be completely broken down by enzymes within the liver and kidneys and excreted in full in the urine. This concept no longer holds true; the main breakdown product parahydroxybenzoic acid has now been detected in human blood and breast milk, as well as human breast cancer tissue. Underarm deodorants and antiperspirants and products applied to the breast area have been suggested as a possible source of parabens found in breast tissue, but no research on the route of exposure has been carried out. Nor has a causal relationship between paraben exposure and breast cancer been established, but what is known is that parabens exert oestrogenic activity along with other environmental pollutants and a lot more ongoing research looking at accumulative effects of these xeno-oestrogens is required.

Conditions associated with hormonal disruption (such as endometriosis, polycystic ovaries) certainly appear to be on the increase. An important part of the naturopathic approach to the prevention and treatment of these conditions is to reduce exposure to hormone disrupting environmental agents wherever possible. This is not difficult and surprisingly is not a lot more expensive. All it requires is choosing natural products produced by reputable companies that have a long history of providing such items, along with their full ingredient disclosure, over those that don’t. Eating foods that are grown organically also reduces exposure.

Many people are improving their diet for health reasons, but may forget about the personal products and cleaners they use everyday. At Nourish we choose products that are paraben-free, except for several products where there is no other choice, and these are clearly labelled so you know exactly what you are buying and using. To check whether products you are using contain parabens visit the Australian Government Department of Health and Ageing website and look for the article titled “Parabens in deodorants and antiperspirants linked to breast cancer”4 to find the list of commonly used terms for parabens on product labels.

References

Cashman AL & Warshaw EM 2005, Parabens: A review of epidemiology, Structure, Allerginicity and hormonal properties. Medscape (On line) http://www.medscape.com/viewarticle/508430 [Accessed 15th August 2005]
Harvey PW & Darbre P. 2004, Endocrine disrupters and human health: Could oestrogenic chemicals in body care cosmetics adversely affect breast cancer incidence in women? Journal of Applied Toxicology 24:167-176.
Australian Government Department of Health and Ageing (2004), Parabens in deodorants and antiperspirants linked to breast cancer. National Industrial Chemicals Notification Assessment Scheme. (On line) http://www.nicnas.gov.au/news/20040123-parabenbreastcancer.asp [Assessed 15th August 2005].

Parabens - Their Safety is in Question

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