Testosterone may be the main sex hormone in men, but it plays an important role in the physical growth and strength of both sexes. Specifically, testosterone is a factor in determining brain function, bone density, and heart health.
But studies carried out over the past half century have shown that testosterone levels have been dropping. The result: frightening health conditions, including reduced semen quality in men and genital malformations in young boys.
Now, a new study involving the 2011-2012 U.S. National Health and Nutrition Examination Survey shows that this might be tied to the use of phthalates, a chemical added to plastics to enhance their flexibility, transparency, and durability. Phthalates can also be found in shampoo, detergent, nail polish, hair spray, and adhesives.
It’s believed these phthalates negate the effects of testosterone on the body. “We found evidence [that] reduced levels of circulating testosterone were associated with increased phthalate exposure in several key populations, including boys ages 6-12, and men and women ages 40-60,” noted John D. Meeker, one of the study’s lead authors.
“This may have important public health implications, since low testosterone levels in young boys can negatively impact reproductive development, and in middle age can impair sexual function, libido, energy, cognitive function and bone health in men and women.”
Meeker said he hopes the study will prompt policymakers to “take steps to limit human exposure” to dangerous chemicals like phthalates.
