Children who are frequently exposed to two chemicals commonly found in plastic and metal food packaging are at risk for obesity or diabetes, according to new US studies.
Researchers at New York University have found that high levels of a certain type of phthalate - used to make plastic softer - found in urine samples were associated with a higher risk of insulin resistance in adolescents.
In a second study, researchers at the University of Michigan found that bisphenol A (BPA) - used in plastic bottles, aluminum cans and canned food - was linked to obesity and "overflowing" silhouettes.
According to official data from the US Centers for Disease Control, about one in six teens in the United States is obese.
"Certainly unhealthy diet and lack of physical exercise are the main causes of this condition. "However, there is growing evidence that environmental chemicals are contributing to childhood obesity," explains Dr. Leonardo Tracante, a pediatrician at New York University.
The study on phthalates
Dr. Tracante and his team meta-analyzed data from a large-scale health and nutrition study conducted in 2003-2008. In it, analyzes of urine and blood samples were recorded from a total of 766 adolescents aged 12-19 years.
They found that the detection of a specific type of phthalate, known as DEHP (Di-2-ethylhexylphalate) in urine, was directly linked to the risk of insulin resistance in these adolescents - a condition that is a harbinger of diabetes.
However, the researchers do not claim that these findings show that eating packaged foods leads to insulin resistance. It is possible, they explain, that some children who already show insulin resistance follow unhealthy eating habits, as a result of which they often consume packaged foods and therefore accumulate higher levels of phthalates in their urine.
Dr. Tracade, however, points out that phthalates may affect the way the hormone insulin is secreted. "I advise parents to avoid buying plastics that contain DEHP. "Also, they should not wash plastic containers in the dishwasher, while when they are worn out they should end up in the trash," he says.
The study for bisphenol A
On the other hand, experts from the University of Michigan conducted a meta-analysis of the same nutritional study in order to compare the levels of bisphenol A (BPA) in the urine of children and adolescents aged 6-18 years.
According to a report in the journal Pediatrics, analyzing data from a total of 3.370 children, they found that bisphenol A - a chemical that mimics estrogen by "tricking" their receptors - was not linked to insulin resistance.
Children, however, who had high levels of BPA in their urine were more likely to be obese, or tend to have disproportionate waist-to-height ratios compared to the rest.