Scientists think that even in low doses the exposures to phthalates and several other common chemicals might reduce the levels of testosterone in men. Richard Stahlhut, A Preventive Medicine resident at the University of Rochester said that the exposure to such chemicals leads to the increase of obesity rates and an epidemic of such related disorders like Type 2 diabetes. He outlined that some significant declines in both testosterone levels and quality of sperm have been spotted during the last several decades in the United States and some other countries. Stahlhut stated that phthalates should definitely be in the list of chemicals that require a careful study.
It is worth mentioning that phthalates have been actively used for more than half a century. However, only now did scientist start thinking about the possible health problems to which the chemical might lead. Studies made on animals showed that phthalates consistently depress the levels of testosterone. Recently, while performing their studies on humans, scientists have found that the hazardous chemicals are linked to poor quality of semen in men. This also refers to reproductive organs in boy babies.
A group of scientists, working together with Stahlhut, launched a hypothesis that phthalates could be the cause of obesity because low testosterone seems to increase belly fat and pre-diabetes in men. The group made analysis on urine, blood, as well as other data provided by the National Health and Nutrition Examination Survey, which is a multi-ethnic, cross-section sampling of the population living in the United States, gathered routinely by the Centers for Disease Control and Prevention.
According to the data from the period of 1999-2000, most recent years that the levels of the dangerous chemical were available, 1,451 adult men had data on chemicalís exposures, obesity, as well as waist circumference. A significant number of these men, and namely 651, in addition had fasting levels of glucose and insulin required to estimate the resistance to insulin. As it was expected the researchers found that some phthalates metabolites had a strong connection with the abdominal obesity. The discovery showed that men with a high level of phthalates, found in their urine, had more resistance to belly fat and insulin.
The research was made with adjustments for several other factors that might influence the results. These include menís: age, race, food intake, as well as the levels of physical activity and smoking. The study showed that about 75 percent of all Americans have in their urine measurable levels of phthalates.