Study Links Phthalates to Diabetes

High blood levels of phthalates — chemicals that are commonly used to soften plastics— may double the risk of type 2 diabetes in older adults, Swedish researchers are reporting. While the research is disputed, the research could add pressure to conduct more tests to determine what are the chemicals’ comprehensive effects on human health, if any.

As Steven Reinberg reports for HealthDay, the Swedish researchers measured participants’ blood sugar, insulin levels, and levels of toxins from the breakdown of phthalates. The results showed that diabetes was more common among those who were overweight and had high cholesterol levels, but the researchers also found an association between blood levels of phthalates and diabetes.

The association remained after eliminating obesity, cholesterol, smoking, and exercise from the equation. However, those with higher levels of phthalates had roughly twice the risk of developing diabetes compared to those with lower levels.

The study was reported in the June edition of diabetes care. Reinberg quotes Swedish researcher, Monica Lind, an associate professor of environmental medicine in the section of occupational and environmental medicine at Uppsala University:

Our study supports the hypothesis that certain environmental chemicals can contribute to the development of diabetes. Even at relatively low levels of phthalate in the blood, the risk of getting diabetes begin to rise.

Phthalates are used in toys, vinyl flooring and wall coverings, detergents, lubricating oils, food packaging, blood bags and tubing, and pharmaceuticals. They also are used in nail polish, hair sprays, and shampoos. Previous studies have linked phthalates to estrogen disruption and reproductive problems in men.

Critics of the study pointed out that exposure to the chemicals showed only an association with diabetes, not a cause and effect, reports Denise Mann of WebMD Health News. Exactly how phthalates may increase the risk of diabetes is not known. “Experimental studies are also needed regarding what biological mechanisms might underlie these connections,” Lind says.

The U.S. Food and Drug Administration (FDA) “does not have compelling evidence that phthalates, as used in cosmetics, pose a safety risk,” according to FDA website. If the agency finds that there is a health risk, it will advise the public and manufacturers, it says.

Companies are not required to test the long-term health effects of chemicals before using them in consumer products in the United States, Lind says. This means that the dangers of hazardous chemicals are not known until they are already widely used. The health effects of chemicals should be tested before they reach consumers, in a similar way that drugs are tested before they are approved for general use.

The American Chemical Council (ACC) pointed out flaws in the study, Mann reports. “The authors overstate the conclusions and, most important for the public to know, the study does not show any cause-and-effect relationship between phthalate exposure and diabetes,” says Steve Risotto, senior director of the ACC Phthalate Esters Panel, in a written statement. “Phthalates have a long history of safe use and have been extensively reviewed by governments around the world, including the CDC, which found that average phthalates exposure levels are actually far below those set by the government to be protective of human health.”

Some companies are phasing out the use of phthalates in their products, but there is no practical way to choose phthalate-free products, according to the Environmental Working Group, which is working to rid hazardous chemicals from consumer products. Reinberg writes:

Sometimes the print on ingredient labels is too small to read, and different names are often used for the same plasticizing chemicals. And some products lack ingredient labels even though they’re required by federal regulations.