Lower Dose Parabens Might Increase Breast Cancer Risk

by Jennifer Ohayon, PhD Postdoctoral Research Fellow, Silent Spring Institute

Previous studies may be greatly underestimating the toxicity of parabens with respect to breast cancer risk and reproductive problems according to new research published by the Silent Spring Institute and our collaborators.

Estrogen-mimicking chemicals called parabens are a class of preservatives widely used in consumer products like shampoos, cosmetics, body lotions, and sunscreens. Despite mounting concerns over the potential toxicity of parabens, earlier scientific research indicated that parabens had a weak effect on cell proliferation. The problem is these studies look only at parabens in isolation and fail to consider how these chemicals interact with other agents that regulate cell growth. To better reflect how parabens might increase breast cancer risk in real life, our collaborators at UC Berkeley exposed cells to parabens while also activating HER2, a human epidermal growth factor receptor. The research found that once the HER2 pathway was activated, parabens stimulated breast cancer cell growth at concentrations 100 times lower. This suggests that parabens may be dangerous at much smaller doses than earlier studies revealed.

Look for products labeled “paraben-free” and reduce the number of personal care products you use to decrease the number of untested chemicals entering your body. Also visit MBCC’s website to read about their Let’s Talk Prevention: Reducing Toxic Exposures Tour and find more tips for reducing exposure to parabens and other chemicals of concern.

This research was published in Environmental Health Perspectives and carried out by the Silent Spring Institute, the University of California, Berkeley, the Lawrence Berkeley National Laboratory, and the University of Florida. The California Breast Cancer Research Program helped fund this research. A link to the paper can be found here.