Common Plastics Chemical Might Boost Diabetes Risk
High blood levels of chemicals called phthalates, which are found in soaps, lotions, plastics and toys, may double the risk for type 2 diabetes among older adults, Swedish researchers say.
"Our study supports the hypothesis that certain environmental chemicals can contribute to the development of diabetes," said lead researcher Monica Lind, an associate professor of environmental medicine in the section for occupational and environmental medicine at Uppsala University.
"Most people come into daily contact with phthalates as they are used as softening agents in everyday plastics and as carriers of perfumes in cosmetics and self-care products," she added.
The study's implications "must be to cut down on plastics and choose self-care products without perfumes," Lind said.
But the research does not prove cause and effect. To find out whether phthalates (pronounced THAL ates) truly are risk factors for diabetes, further studies are needed that show similar associations, she said.
"Experimental studies are also needed regarding what biological mechanisms might underlie these connections," Lind stressed.
The report was published online April 12 and in the June print edition of Diabetes Care.
For the study, Lind's team collected data on more than 1,000 Swedish men and women, age 70, who took part in the Prospective Investigation of the Vasculature in Uppsala Seniors Study.
The researchers measured the participants' blood sugar, insulin levels and levels of toxins from the breakdown of phthalates.
As expected, they found diabetes was more common among those who were overweight and had high cholesterol.
And they also found an association between blood levels of some phthalates and diabetes. That association remained even after taking into account obesity, cholesterol, smoking and exercise.
For people with high phthalate levels, the risk of developing diabetes was about double compared to those with lower levels, the investigators found.
Some phthalates were also linked to disrupted insulin production, the researchers said. Insulin is a hormone that helps deliver blood sugar into the body's cells for energy. Without insulin, or with too little of the hormone, too much sugar stays in the blood, setting the stage for diabetes.
"Even at relatively low levels of phthalate in the blood, the risk of getting diabetes begins to rise," Lind added.
Other studies have linked these chemicals with breast growth in boys and reproductive problems in men, possibly caused by estrogen disruption.
Phthalates are used in hundreds of products, such as toys, vinyl flooring and wall coverings, detergents, lubricating oils, food packaging, pharmaceuticals, blood bags and tubing, according to information from the U.S. Food and Drug Administration. Personal care products, such as nail polish, hair sprays and shampoos, also contain phthalates.
At present, "the FDA does not have compelling evidence that phthalates, as used in cosmetics, pose a safety risk," according to the FDA website.
In the United States, companies are not required to test the long-term health effects of chemicals before using them in consumer products. Lind said this means the dangers of hazardous chemicals aren't known until they are already widely used.
Lind said the health effects of chemicals should be tested before they reach the consumer market similar to the way drugs get tested before being approved.
"We are looking at a tip of an iceberg," she said in terms of a possible health crisis. "We are just scratching the very top of the iceberg."
The way the system is designed, if phthalates were banned, they would be replaced by other chemicals about which even less is known, Lind said.
According to the Environmental Working Group, a group trying to rid hazardous chemicals from consumer products, there is no practical way to choose phthalate-free products. 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.
That said, some of the names to look for in cosmetics, self-care products, solid air fresheners, and scented candles are: mono-methyl phthalate (MMP), mono-ethyl phthalate (MEP) and mono-isobutyl phthalate (MiBP), which are types of the chemicals dimethylphthalate (DMP), diethyl phthalate (DEP) and di-isobutyl phthalate (DiBP). DMP is also used in ink and as a softening agent in plastics.