E-Mail IMAGE: Senior author Laura Vandenberg is an associate professor in the UMass Amherst School of Public Health and Health Sciences. view more Credit: UMass Amherst Low doses of propylparaben - a chemical preservative found in food, drugs and cosmetics - can alter pregnancy-related changes in the breast in ways that may lessen the protection against breast cancer that pregnancy hormones normally convey, according to University of Massachusetts Amherst research. The findings, published March 16 in the journal Endocrinology, suggest that propylparaben is an endocrine-disrupting chemical that interferes with the actions of hormones, says environmental health scientist Laura Vandenberg, the study's senior author. Endocrine disruptors can affect organs sensitive to hormones, including the mammary gland in the breast that produces milk.