Phthalates raise blood pressure in children, study suggests

Phthalates are odourless, colourless and just about everywhere: flooring, plastic cups, beach balls, plastic wrap, intravenous tubing and - according to the Centers for Disease Control and Prevention - the bodies of most Americans.

A growing collection of evidence suggests dietary exposure to phthalates - which can leach out of packaging and mix with food - may cause metabolic and hormonal abnormalities, especially during early development.

New research published in The Journal of Pediatrics suggests that certain types of phthalates could pose another risk to children: compromised heart health. Drawing on data from a survey of nearly 3000 children and teens, researchers at NYU Langone Medical Center, in collaboration with the University of Washington, the University of Cincinnati and Penn State University School of Medicine, have documented a connection between dietary exposure to DEHP (di-2-ethyhexylphthalate), a common class of phthalate widely used in industrial food production, and elevated systolic blood pressure.

“Phthalates can inhibit the function of cardiac cells and cause oxidative stress that compromises the health of arteries. But no one has explored the relationship between phthalate exposure and heart health in children,” said lead author Leonardo Trasande, MD, MPP, associate professor of pediatrics, environmental medicine and population health at NYU Langone Medical Center.

“We wanted to examine the link between phthalates and childhood blood pressure in particular given the increase in elevated blood pressure in children and the increasing evidence implicating exposure to environmental exposures in early development of disease.”

Hypertension is becoming increasingly prevalent among children and is commonly attributed to the obesity epidemic. Recent surveys indicate that 14% of American adolescents how have pre-hypertension or hypertension.

“Obesity is driving the trend, but our findings suggest that environmental factors may also be a part of the problem,” Dr Trasande said. “This is important because phthalate exposure can be controlled through regulatory and behavioural interventions.”

The researchers examined six years’ worth of data from a National Centers for Health Statistics survey. Phthalates were measured in urine samples using standard analysis techniques. Controlling for a number of potential confounders, the researchers found that every three-fold increase in the level of breakdown products of DEHP in urine correlated with approximately 1 mm mercury increase in a child’s blood pressure.

“That increment may seem very modest at an individual level, but on a population level such shifts in blood pressure can increase the number of children with elevated blood pressure substantially,” Dr Trasande said. “Our study underscores the need for policy initiatives that limit exposure to disruptive environmental chemicals, in combination with dietary and behavioural interventions geared toward protecting cardiovascular health.”

The research was published in The Journal of Pediatrics on 28 May 2013.