Parabens (methylparaben, propylparaben, ethylparaben, or butylparaben), the most common class of preservatives used in underarm deodorants and cosmetics, provoke controversy because they are thought to mimic the hormone estrogen, which some studies show plays a role in the development breast cancer and urogenital abnormalities.
In fact, a 2004 study published in the Journal of Applied Toxicology found traces of five parabens were found in the breast-cancer tumors of 19 out of 20 women studied-admittedly too small a study to prove a causal relationship between parabens and breast cancer, but still notable because researchers detected the presence of intact parabens unaltered by the body's metabolism, a key indication that the chemical can penetrate skin and persist in breast tissue. Another 2003 study, published by the European Journal of Cancer Prevention, concluded that the
"frequency and earlier onset of antiperspirant/deodorant usage with underarm shaving were associated with an earlier age of breast cancer diagnosis." And gents? We only have three words for you: Decreased. Sperm. Count.
To be fair, the The U.S. Food and Drug Administration doesn't believe that we should be concerned about the use of parabens in cosmetics because they're generally applied at very low levels. With parabens appearing in 25,000 of the cosmetics and skincare products documented by the Environmental Working Group, however, one unanswered question is whether greater exposure to the chemicals could offset their lower potency.
Despite the lack of consensus, and as research continues to take place, we believe it only prudent to take a precautionary approach-and be safe, rather than sorry.
Difficulty level: Easy