People who dine regularly on fast-food fare are going home with more than a full belly, according to a new study: They’re likely getting a dose of industrial chemicals, too.
Describing their conclusions as “striking,” researchers at George Washington University reported last week that they found significantly higher levels of certain types of phthalates in study participants who ate fast food than in those who avoided the Golden Arches and its competitors. But it’s not about the food, they concluded. It’s about how the food is processed and prepared.
“We’re not trying to create paranoia or anxiety, but I do think our findings are striking,” Ami Zota, an assistant professor of environmental and occupational health at George Washington University, told the Washington Post. “It’s not every day that you conduct a study where the results are this strong.”
Phthalates, a class of chemicals found in hundreds of consumer products, can leach, migrate, or off-gas from these products and enter the body through the skin, the lungs, and in the case of Zota’s research, via a meal at your favorite fast-food restaurant. These chemicals have been linked in a number of studies to adverse health effects, including cancer.
Earlier studies suggest that food sources contribute significantly to overall exposure to three specific chemicals — DEHP, DiNP, and BPA — that have been associated with health issues including diabetesallergic diseaseshigh blood pressure, and childhood development disorders. In 2014, the U.S. Department of Health and Human Services concluded that DEHP is “reasonably anticipated to be a human carcinogen.” Zota and her team set out to determine whether a fast-food habit would increase the levels of exposure.
“Phthalates have been shown to leach into food from PVC in materials like tubing used in the milking process, lid gaskets, food preparation gloves, conveyer belts, and food-packaging materials,” Zota and her coauthors write in the study, published in the journal Environmental Health Perspectives. “In fact, an intervention study reported that urinary BPA and DEHP were reduced by 66 percent and 53 to 56 percent, respectively, when participants’ diets were restricted to food with limited packaging.”
Using data from U.S. nutrition surveys conducted between 2003 and 2010, which included a chemical analysis of the participants’ urine samples, Zota’s team found that about a third of the nearly 9,000 people surveyed reported eating a fast-food meal in the 24 hours prior to providing a urine sample. And those fast-food eaters all had higher levels of DEHP and DiNP.
Compared with subjects who ate no fast food, those who said they had eaten a small meal had 16 percent higher DEHP levels and 25 percent more DiNP. Those who said they had eaten a more sizable meal had DEHP and DiNP levels that were 24 percent and 39 percent higher, respectively. Fast-food intake did not affect BPA levels.
Those results held true even after researchers controlled for various lifestyle and demographic factors, such as age, gender, ethnicity, and household income.
Because of the cross-sectional design of the surveys the team analyzed, the results do not prove a causal relationship between fast food and higher levels of these chemicals, but Zota argued that the nature of the fast-food environment — machinery, conveyor belts, and plenty of plastic — make a strong argument for more research. “I really hope this study helps raise public awareness about the exposure problems associated with our industrialized food system,” she said.
While you’re waiting for the next round of studies, you can lower your own exposure to phthalates by opting for organic whole foods over processed fare. For tips on how to stock your cupboards with healthier options, check out “The Clean-Eats Pantry” from our May 2008 issue.