A new study explains why eating more homemade meals could be better for people's health.
Per- and polyfluoroalkyl substances (PFAS) are a group of chemicals that humans have created. They are in packaged foods, household products, kitchen appliances, and contaminated water, among other sources.
According to the United States Environmental Protection Agency (EPA), research has found links between PFAS and reproductive and developmental problems, liver and kidney disease, adverse effects on the immune system, and carcinogenic effects in rodents.
PFAS do not break down and, therefore, build up with time. Across most studies, a common conclusion has been that PFAS levels have links with high cholesterol in humans.
Now, new research in the journal Environmental Health Perspectives adds to these previous findings, suggesting that people who eat out more often are more likely to have higher PFAS levels in their blood.
The findings fall in line with recent research that found PFAS to be very common in fast food packaging. Researchers at the Silent Spring Institute in Newton, MA, conducted both this previous study and the new one.
Eating in may be safer than eating out
For the new study, scientists analyzed data from the National Health and Nutrition Examination Survey (NHANES) — a research program designed by the Centers for Disease Control and Prevention (CDC) to track the "health and nutritional status of adults and children in the United States."
The Silent Spring Institute researchers obtained information on 10,106 NHANES participants who had given detailed information on their diets and eating patterns. Specifically, the participants self-reported on the foods they consumed in the previous 24 hours, 7 days, 30 days, and 12 months.
The scientists also took blood samples from these individuals and analyzed these for traces of PFAS.
Overall, the researchers found a correlation between eating at home and having lower levels of PFAS in the blood. Ninety percent of the home cooked meals contained grocery store ingredients.
By contrast, those who ate more frequently at restaurants and consumed fast foods had more PFAS in their blood.
The findings, according to the researchers, suggest that food from restaurants and fast food places contains higher levels of PFAS due to contact with food packaging that contains PFAS.
Moreover, the study also found that people who regularly ate microwave popcorn also had higher levels of PFAS. This finding was in agreement with previous studies.
Strengths and limitations of the study
Study co-author Laurel Schaider, Ph.D., who is an environmental chemist at Silent Spring, comments on the strengths of the research, saying, "This is the first study to observe a link between different sources of food and PFAS exposures in the U.S. population."
"Our results suggest migration of PFAS chemicals from food packaging into food can be an important source of exposure to these chemicals," she continues.
However, the researchers also acknowledge that the fact that they only collected information on long-chain PFAS — as these were the most frequent substances they found — limits their results.
Recently, producers in the U.S. have replaced long-chain PFAS with newer and allegedly less harmful versions due to increasing health concerns.
But, while manufacturers made these changes in recent years, the present study only collected data from 2003 until 2014.
Still, many experts warn that the newer PFA varieties are just as harmful as the older ones, and study co-author Kathryn Rodgers, a staff scientist at Silent Spring, points out the additional harm that BPA and phthalates may cause.
These latter substances can also present in food packaging, and research has suggested they disrupt normal hormonal and endocrine function.
"The general conclusion here is the less contact your food has with food packaging, the lower your exposure to PFAS and other harmful chemicals."
"These latest findings will hopefully help consumers avoid these exposures and spur manufacturers to develop safer food packaging materials."