In the 1990s, parabens were deemed xenoestrogens―agents that mimic estrogen in the body. “Estrogen disruption” has been linked to breast cancer and reproductive issues. And in 2004 British cancer researcher Philippa Darbre, Ph.D., found parabens present in malignant breast tumors. As a result, experts in many countries are recommending limits on paraben levels in cosmetic products. What’s more, watchdog organizations worry that if parabens can be stored in the body, over time they could have a cumulative effect and pose a health risk.