According to a study published online in the journal Environmental Research, a connection has been found between obesity in young children - including waist circumference and increased body mass index (BMI) - and exposure to the chemical group known as phthalates, by investigators from the Children's Environmental Health Center at The Mount Sinai Medical Center.

The National Institute for Environmental Health Sciences, The National Cancer Institute, and the U.S. Environmental Protection Agency funded the study.

Phthalates are manufactured, endocrine-disrupting chemicals that can mimic the body's natural hormones. Phthalates are primarily used to soften polyvinyl chloride (PVC) in products, such as wall and floor coverings, personal-care products, medical devices, and food processing materials.

Although it is known that poor diet and lack of exercise are associated with obesity, several studies suggest that environmental chemicals - including phthalates - could be linked to the increasing rates of childhood obesity.

This is the first investigation to analyze the association between exposure to phthalates and measurements used to identify obesity in children.

387 black and Hispanic children in New York City were enrolled to participate in the study. Using urine samples from the participants, the researchers measured phthalate concentrations. One year later, the participants' BMI, waist circumference, and height were measured.

The team discovered that more than 97% of study participants had been exposed to phthalates commonly found in personal care products, such as cosmetics, varnishes, perfume, lotions, and medication or nutritional supplement coatings. The phthalates included monoethyl phthalate (MEP), as well as other low molecular-weight phthalates.

Furthermore, they discovered a link between BMI and waist circumference among overweight children with concentrations of these phthalates. For instance, overweight girls with the highest exposure to MEP had a BMI 10% higher than girls with the lowest exposure to MEP.

Lead author of the study Susan Teitelbaum, Ph.D., Associate Professor in the Department of Preventive Medicine at Mount Sinai School of Medicine explained:

"Research has shown that exposure to these everyday chemicals may impair childhood neurodevelopment, but this is the first evidence demonstrating that they may contribute to childhood obesity. This study also further emphasizes the importance of reducing exposure to these chemicals where possible."

According to the U.S. Centers for Disease Control and Prevention, the number of obese children aged 6 to 11 in the U.S. has increased from 7% in 1980, to over 40% in 2008. Currently, over 15% of children in the U.S. between 6 to 19 years of are considered obese, while over 1 in 5 children in public schools in New York City are obese.

Dr. Teitelbaum said:

"While the data are significant, more research is needed to definitively determine whether phthalate exposure causes increase in body size."

Phthalate studies point to several health problems

Researchers from Brigham and Women's Hospital published a report in Environmental Health Perspectives which revealed that women with high phthalate levels in their urine have a considerably higher risk of developing diabetes, compared to those with the lowest levels. (Link to article)

Scientists from the University of Rochester Medical Center found in a pilot study that young boys whose mothers had high phthalate urine levels when they were pregnant were less likely to "play like boys" - engage in boyish banter, play fighting, and use masculine toys. (Link to article)

Phthalate concentrations were found in infants' urine by researchers from the CDC in Atlanta and the University of Rochester School of Medicine and Dentistry. The investigators said phthalates are widely used in baby care products, such as lotion, talc and shampoo. (Link to article)

A Finnish study found a link between phthalates and diabetes risk among elderly people; even when circulating phthalate levels were only moderately elevated their risk doubled. (Link to article)

At Columbia University's Mailman School of Public Health, scientists found "prenatal exposure to phthalates may adversely affect child mental, motor and behavioral development during the preschool years". (Link to article)

Scientists from the University of Michigan, in a large-scale study, confirmed a link between phthalate and BPA concentrations and thyroid hormone levels. Thyroid hormones play a key role in reproduction, metabolism, energy balance and other body functions. (Link to article)

Written by Grace Rattue