Most people who have heard me talk know that I am focused on finding the cause of breast cancer so that we can prevent it. Many people have suggested that the answer may well be the environment. The recent Institute of Medicine Report on Breast Cancer and the Environment noted the known risk factors such as hormone replacement therapy, obesity and alcohol. But what about all the chemicals that are ubiquitous in our lives? Could they be culprits? The IOM said it couldn’t answer this question because not enough research has been done.
This is undoubtedly part of the reason why a lot of media attention has been directed at a new study on parabens and breast cancer by researchers at the University of Reading in the UK.
Parabens are chemicals that are widely used as antimicrobial preservatives in numerous consumer products, including pharmaceuticals, foods and cosmetics. In 2004 the same research group reported finding parabens in breast tumor tissue. They were interested in parabens because there is some evidence that these compounds have some estrogenic properties, and could potentially influence the breast.
In their most recent study, published in the January 12 online issue of the Journal of Applied Toxicology, the group looked at breast tissue from 40 women who had a mastectomy between 2005 and 2009 because they had breast cancer to see if they could find parabens in the noncancerous breast tissue. And while I am happy to see more research being done in women as opposed to rats, this study actually brings more questions than answers.
The good news is that the researchers actually looked to see if there were parabens in the breast tissue, rather than just hypothesizing that it might be there. And indeed they found parabens in the 160 tissue samples (four from each woman) they studied, including samples taken from seven women who said they did not use any underarm deodorants or antiperspirants, the presumed source. They also found that there was no difference between the amount of parabens found in the breast tissue of the women who used antiperspirants or deodorants and those who did not, suggesting that there must be another source.
The bad news is that they did not look to see if women without breast cancer also have parabens in their breast tissue. The issue is not whether it is there but whether we all have it or only the women with breast cancer.
As I have often explained, to get breast cancer, you need to have mutated cells as well as a local tissue environment that is egging them on. It is certainly possible that parabens can contribute to this environment. However, this study only tells us that they are ubiquitous in the cancerous breast. That does not mean that they are the cause of cancer. It is like noticing that all drug addicts drink milk and concluding that drinking milk leads to drug addiction. Before we get too carried away we need to see what the rest of us have in our breasts!