Additional Research Links Parabens in Personal Care Products to Breast Cancer
The use of certain personal care products, such as deodorant, has been cited as a potential risk factor for the development of breast cancer. An ingredient, known as paraben, is often used as a preservative in such products and has been found in low concentrations in breast cancer tumors. Researchers with the University of Reading (UK) continue to study the association, finding that women with breast cancer do have at least one paraben chemical in their body tissues, and that the rate appears to be rising.
Dr. Philippa Darbre and colleagues examined breast tissue collected from 40 women who had had mastectomies due to breast cancer in England between 2005 and 2008. In each patient the samples came from four different serial locations from the axilla (armpit) to the sternum (breast bone). There were a total of 160 samples taken and 158 of those included trace levels of parabens. Ninety-six of the samples contained all five of the most common paraben ester forms.
Dr. Darbre has been studying parabens for more than 10 years and notes that she did a similar smaller study in 2004, but the samples collected during this study were about four times higher than those from her previous work which she said was surprising.
"Many of the concentrations of the parabens measured in these breast tissues would be sufficient to drive the growth of oestrogen-dependent human breast cancer cells in the laboratory. (However), since 2004, many manufacturers (although not all) have been removing parabens from the underarm deodorant/antiperspirant products and so I was rather surprised when we found higher levels of parabens in these breast tissues (sourced after 2004)," Darbre said.
Although underarm deodorants are most commonly cited as a potential cause of breast cancer because many types of breast cancer develop in the area of the breast closest to the armpit, some of the breast samples containing paraben traces were collected from women who said they had never used such products indicating the chemicals originated from a different source.
Some parabens are found naturally, such as methylparaben in blueberries. But all commercially used parabens are synthetically produced for products such as moisturizers, shaving gels, spray tanning solutions, makeup and toothpaste. Parabens slightly mimic estrogen, which is a hormone known to play a role in the development of breast cancer.
Over the years, observational studies such as this has been used as a debate on whether or not it is safe for women to use cosmetic products. A 2005 safety assessment concluded that paraben-containing cosmetics do not pose a health risk based on the current evidence available. Darbre states, “Although estrogen is an acknowledged component in the development of breast cancer, it remains to be established as to whether environmental chemicals with estrogenic (estrogen-like) properties contribute a functional component to the disease process.".
Dr. Darbre does suggest however that women reduce the amount they use because “we simply use too much in the modern world – too much for our body systems and too much for the wider environment.”
Barr L, Metaxas G, Harbach CAJ, Savoy, LA, Darbre PD. Measurement of paraben concentrations in human breast tissue at serial locations across the breast from axilla to sternum. Article first published online: 12 JAN 2012. Journal of Applied Toxicology
DOI: 10.1002/jat.1786 (Early View - Online Version of Record published before inclusion in an issue),
Darbre PD, Harvey PW. Paraben esters: review of recent studies of endocrine toxicity, absorption, esterase and human exposure, and discussion of potential human health risks, Journal of Applied Toxicology Volume 28, Issue 5, pages 561–578, July 2008, DOI: 10.1002/jat.1358