Researchers analyzed urine samples from 2,350 women who participated in the long-running National Health and Nutrition Examination Survey, a nationally representative sample of American women. They were looking for concentrations of chemicals known as phthalates, which are often found in personal care products and in adhesives, electronics, products used to manufacture cars, toys, packaging and even some coatings for medications.
Phthalates are considered "endocrine-disrupting" because they can alter normal regulation of certain mechanisms in the body, including hormone regulation, and have been tied in previous research to diabetes and obesity risk, Dr. Kenneth Spaeth, director of the Occupational and Environmental Medicine Center's department of population health at North Shore University Hospital in Manhasset, N.Y., told HealthPop. He was not involved in the study.
The researchers found that women with the highest concentrations of two types of phthalates - mono-benzyl phthalate and mono-isobutyl phthalate - were nearly two times more likely to have diabetes compared to women with the least amounts of these chemicals. Women with moderately high levels of the phthalates mono-n-butyl phthalate and di-2-ethylhexyl phthalate were 70 percent more likely to have diabetes compared to their counterparts.
The findings were published in Environmental Health Perspectives, a journal published by the government's National Institute of Environmental Health Sciences.
"This is an important first step in exploring the connection between phthalates and diabetes," said Dr. Tamara James-Todd, a researcher in women's health at Brigham and Women's Hospital in Boston, said in a press release. The researchers could not prove that phthalates caused diabetes or having diabetes increased concentrations of the chemicals in a person's body.
"We know that in addition to being present in personal care products, phthalates also exist in certain types of medical devices and medication that is used to treat diabetes and this could also explain the higher level of phthalates in diabetic women," she added. "So overall, more research is needed."
One of the problems is that chemicals like phthalates are practically unavoidable, according to Spaeth.
"These chemicals are unfortunately ubiquitous," Spaeth explained. "It's pretty clear from studies that we're exposed all day long to these various household or personal care products."
Spaeth says it's a real challenge to reduce phthalate exposure because sometimes the chemical is a metabolic byproduct of another ingredient or a product label may not say it contains phthalates only for phthalates to be found in the packaging the product came in, which does not need to be mentioned on a product label.
"It's really hard to make informed decisions about these kinds of things," he said. "Maybe we'll get to a point when the health effects are more widely recognized, that there will be incentive to change how products are made and packaged."
However Spaeth did say research has shown phthalates can find their way into household dust and people sometimes ingest them that way, so simple steps like frequent vaccuming and dusting, or washing your hands regularly before eating may decrease risk.