WASHINGTON, DC – People exposed to high levels of phthalates – which are endocrine-disrupting chemicals found in plastics and some personal care products, – are showing reduced testosterone levels.

Phthalates found in plastics can block hormones involved in sexual and cognitive function.

A report published Aug. 14 online in the Journal of Clinical Endocrinology & Metabolism, said testosterone contributes to many functions in both sexes, including physical growth and strength, brain function, bone density and cardiovascular health.

The study was conducted by John D. Meeker, MS, ScD, and Kelly K. Ferguson, PhD, of the University of Michigan School of Public Health in Ann Arbor.

Other research over 50 years has shown a trend in declining testosterone in men along with a rise in certain health conditions, which include reduced semen quality and genital malformations in newborn boys. Animal and cellular studies have found that some phthalates block the effects of testosterone on body organs and tissues.

These chemicals are widely used in flexible PVC plastics and personal care products

Findings include a relationship between phthalate exposure and testosterone levels at various life stages: women ages 40-60 showed increased phthalate concentrations that were associated with a 10.8 to 24 percent decline in testosterone levels. Among boys ages 6-12, increased concentrations of metabolites of a phthalate called di-(2-ethylhexyl) phthalate, or DEHP, was linked to a 24 to 34.1 percent drop in testosterone levels.


Dr. J.D. Knytych, NMD, said the study supports what many naturopathic doctors already know.

“This study is finding a mechanism of what we are seeing and what I am seeing in my practice in men above 50 with the lower-end of normal testosterone levels, but not without testosterone.”

Knytych said he is seeing problems in younger men as well.

“Men below 40, even in their 20s, are coming in hypogonadic.”

Knytych said to address the issue is to diminish environmental xenoestrogen exposure, and “to treat the low hormone is to replace that for now or to find mechanisms that can help their own production. Certainly the naturopathic approach to all disease to look at lifestyle, diet, food selection and stress management.”

Dr. Knytych practices at Knytych Integrative Medicine in Phoenix., http://knytychmedicine.vpweb.com/?prefix=www

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