Parabens are suspected of contributing to breast cancer risk because they have been shown to be endocrine disruptors. Parabens are widely used as preservatives in cosmetics and personal care products (including some intended for children), as well as in pharmaceuticals and some processed food. Antiperspirant and deodorant use has also been posited to play a role in breast cancer through its aluminum and paraben content, but this possible connection is far from proven. (Note that most antiperspirants and deodorants currently sold in the U.S. do not contain parabens). Now a new study has reported significant paraben levels in the breast tissue of women with breast cancer.

Latest research finds parabens in breast tissue

The study referenced at the beginning of this news article was designed to investigate the concentrations of parabens in the breast tissue of breast cancer patients. To conduct the study, the authors tested 160 breast tissue samples collected from 40 breast cancer patients who underwent mastectomies in England during the period 2005 to 2008. Levels of five esters of p-hydroxybenzoic acid (parabens) were measured at four locations in the human breast from armpit to sternum.

One or more parabens were measurable in 99% (158/160) of the tissue samples and all five were found in 60% (96/160) of the samples. Median values were highest for n-propylparaben and methylparaben; n-butylparaben, ethylparaben and isobutylparaben 2.1 were detected at lower levels. The authors note that paraben was measured in seven of the 40 patients who reported never having used underarm antiperspirant or other underarm cosmetics. No associations were found between paraben levels and age of study participants (range: 37 to 91 years), length of breast feeding (0 to 23 months), location of tumor within the breast, or tumor estrogen receptor (ER) status. Since breast cancer occurs disproportionately in the upper outer quadrant of the breast (near the armpit), the authors also compared paraben levels between the four regions of the breast sampled. N-propylparaben was found at significantly higher levels in the armpit area than other regions tested.

Study results are inconclusive

While interesting, the study results are inconclusive. There was no comparison to cancer-free women, who might also have elevated paraben levels in their breasts. High paraben levels were not associated with ER+ disease, which contradicts the theory that parabens increase breast cancer risk through estrogenic actions. Nevertheless, it makes sense to choose paraben-free personal care products (especially lotions and creams) to be on the safe side.