Treehugger told me to keep away from parabens so I was looking for a deodorant without them. I’m not up for baking soda just yet, so a-shopping I go (yes, I’m a bad person). Vanessa at Green as a Thistle is partial to Avalon Organics’ (pretty) deodorants. That works for Vanessa because she lives in Canada.
I need one made in Australia. The ones I’ve found all contain parabens. So I wondered, are parabens actually all that bad? The European Union Cosmetic Products Directive doesn’t have a problem with them. But some people (and natural cosmetics manufacturers) say parabens are harmful. I don’t believe everything I read on the web until I’ve found more evidence.
Some products proudly display a paraben-free label. The Campaign for Safe Cosmetics says,
Parabens are absorbed through intact skin and from the gastrointestinal tract and blood. UK researchers found measurable concentrations of six different parabens in 20 human breast tumors. The study highlights the need for more research on the potential link between products containing parabens and increased breast cancer risk.
A description of the UK study  is at PubMed. In research terms, one study with a sample of 20 tumors doesn’t prove much. The study only looked at breast tumors. For results to indicate increased cancer risk, healthy breast tissue needs to be included and a larger sample studied. One such study was Antiperspirant Use and the Risk of Breast Cancer  (with a sample of 1600).
Wikipedia has this to say:
Parabens are considered to be safe because of their low toxicity profile and their long history of safe use; however, a few recent controversial studies have begun to challenge this view. Studies on the acute, subchronic, and chronic effects in rodents indicate that parabens are practically non-toxic. Parabens are rapidly absorbed, metabolized, and excreted.
In regard to the UK study mentioned above,
no causal link with cancer has ever been proven and so far there is no scientific evidence to support any link with any form of cancer.
And the American Cancer Society agrees.
it is biologically implausible that parabens could increase the risk of any estrogen-mediated endpoint, including effects on the male reproductive tract or breast cancer…Worst-case daily exposure to parabens would present substantially less risk relative to exposure to naturally occurring EACs in the diet such as the phytoestrogen daidzein. 
There is some evidence that parabens can
cause skin irritation and contact dermatitis in individuals with paraben allergies, a small percentage of the general population. 
What this means for me is I don’t care how many parabens are in my beauty products (and the references on Wikipedia are a great place to find things).
- Darbre PD, Aljarrah A, Miller WR, Coldham NG, Sauer MJ, Pope GS. (2004) Concentrations of parabens in human breast tumours. J Appl Toxicol. 24(1) pp.5-13.
- Mirick DK, Davis S, Thomas DB. (2002) Antiperspirant use and the risk of breast cancer. J Natl Cancer Inst. 94(20) pp.1578-80.
- Golden R, Gandy J, Vollmer G. (2005) A review of the endocrine activity of parabens and implications for potential risks to human health. Crit Rev Toxicol. 35(5) pp.435-58.
- Nagel JE, Fuscaldo JT, Fireman P. (1977) Paraben allergy. JAMA. 237(15) pp.1594-5.