Exposure to phthalates, a common chemical found in everything from plastics to soaps, already has been connected to reproductive problems & now, for the first time, is linked to abdominal obesity & insulin resistance in adult males, according to a study by the University of Rochester Medical Center. The research adds to the growing suspicion that low-dose exposures to phthalates & other common chemicals may be reducing testosterone levels or function in men, & thereby contributing to rising obesity rates & an epidemic of related disorders, such as Type 2 diabetes, said lead author Richard Stahlhut, M.D., M.P.H., a Preventive Medicine resident at the University of Rochester. The study was published 15 March in the online edition of the journal Environmental Health Perspectives. "Substantial declines in testosterone levels and sperm quality have been observed in the United States and other countries over the last several decades which and it urgently requires explanation," Stahlhut said. "While we can't say yet that phthalates are a definite cause, I am certain they are on the list of chemicals that demands careful study." Phthalates have been widely used for more than 50 years, but only recently implicated as a possible health risk in people. Animal studies have shown consistently that phthalates depress testosterone levels. Recent human studies have found that phthalates are associated with poor semen quality in men and subtle changes in the reproductive organs in boy babies. This connection between phthalates and testosterone helped to establish a basis for the study, Stahlhut said.
