A recent study shows that exposure to PFAS “forever chemicals” during pregnancy may increase the risk of childhood obesity, especially in girls. This builds on previous research showing similar findings.
The study, led by Zhang Weng and colleagues at Fudan University in China, analyzed the prenatal exposure of 464 children to PFAS chemicals. It found that children, particularly girls, exposed to higher levels of certain PFAS had a higher risk of obesity by age 10.
These chemicals, found in a variety of everyday products, have long been linked to various health issues, and this new study strengthens concerns about their impact on childhood obesity.
Key Findings
The researchers measured PFAS levels in umbilical cord blood from the children’s birth and analyzed body fat, waist circumference, and BMI when the children were 10 years old.
Here are some of the key findings:
- Prenatal PFAS exposure, especially to PFNA and PFOS (which are two specific types of PFAS), was associated with increased obesity risk.
- Girls appeared to be more affected than boys, with a higher likelihood of increased weight and body fat.
- Doubling PFNA levels led to a significant rise in obesity risk for girls.
- Body fat measurements, such as skinfold thickness and waist-to-hip ratios, were higher in children with higher prenatal PFAS exposure.
The chemicals focused on in the study—perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and perfluorononanoic acid (PFNA)—are part of a larger class of compounds known as per- and polyfluoroalkyl substances (PFAS). There are estimated to be around 15,000 different chemicals in this class.
PFAS are commonly used in products like non-stick cookware (Teflon), food packaging, and water-resistant clothing. They have been widely detected in the environment and human bodies due to their persistence. (In other words: they do not easily break down, but rather continue building up over time.)
Unfortunately, they are linked to a range of serious health concerns, including cancer, hormone disruption, and immune system issues.
Not the First Time This Link Has Been Found
This isn’t the first time research has shown a link between prenatal PFAS exposure and obesity in children.
A 2023 study led by Brown University researchers found that PFAS exposure during pregnancy was linked to slightly higher body mass indices (BMIs) in children between ages 2 and 5. This study used data from a sample of 1,391 children and their mothers across the U.S.
Similar to the recent Fudan University study, the Brown University researchers found associations between PFAS levels in mothers’ blood during pregnancy and their children’s risk of obesity.
According to Joseph Braun, a professor of epidemiology at Brown University and a senior author of the 2023 study, the findings are concerning because they show that even low levels of PFAS exposure during pregnancy can have an impact on children’s health. “The fact that we see these associations at relatively low levels in a contemporary population suggests that even though PFAS usage in products has decreased, pregnant people today could still be at risk of harm,” Braun said.
In both the 2024 and 2023 studies, researchers stressed that more long-term studies are necessary to understand how prenatal exposure to PFAS affects children as they grow older. This includes looking at whether these children are more likely to face obesity-related health problems, such as diabetes or heart disease, as they reach adolescence and adulthood.
Obesogens: How Everyday Chemicals May Contribute to Obesity
PFAS are part of a larger category of chemicals known as “obesogens,” also known as “metabolic-disrupting chemicals,” or MDCs.
Obesogens are substances that may disrupt how the body regulates weight, leading to increased fat accumulation and a higher risk of obesity. These chemicals can interfere with hormone systems, particularly those involved in metabolism and fat storage.
Obesogens work by altering the body’s metabolic pathways or hormone regulation, potentially leading to changes in how fat is stored and how energy is used. For example, some obesogens may increase the number of fat cells, change the body’s hunger signals, or affect how the body responds to calories.
In addition to PFAS, several other chemicals have been identified as obesogens, including:
- Bisphenol A (BPA) and other bisphenols: Found in plastic products, can linings, and receipt paper, BPA has been shown to interfere with hormones and increase fat storage.
- Phthalates: Commonly used in plastics and personal care products, phthalates may disrupt hormone function and contribute to obesity.
- Atrazine: A widely used herbicide, Atrazine is commonly found in surface and ground waters in areas where it’s used. Animal studies suggest that long-term exposure to atrazine may increase the risk of obesity and insulin resistance, especially when combined with a high-fat diet.
The study of obesogens is still evolving, and researchers are working to understand the full range of chemicals that may contribute to obesity and how they interact with human biology.
What You Can Do
Given the widespread use of PFAS in consumer products and their persistence in the environment, it can be challenging to reduce exposure. However, there are many steps you can take, including:
- Use a water filter. Some water filters are designed to reduce PFAS contamination in drinking water. Here are the most affordable ones I’ve found.
- Switch to PFAS-free cookware. Opt for cast iron, stainless steel, or other alternatives to reduce exposure to PFAS commonly used in non-stick coatings. This guide should help.
- Be cautious with food packaging. Limit your use of takeout containers and microwave popcorn bags, which often contain PFAS (although they are currently being phased out).
- Check product labels and be careful of greenwashing. Look for products that are labeled “PFAS-free,” especially when purchasing things like water-repellent clothing or furniture. Be careful about claims like “PFOA-free” or “PFOS-free,” which only indicate that the product is free from those specific types. (Remember: there are around 15,000 different PFAS.)
- Stay informed. Keep an eye on research and government regulations surrounding PFAS to make informed decisions about the products you use in your home. I try to keep readers as updated as possible via my weekly newsletter.
- Learn more. If you’d like to dive deeper into what PFAS are and more ways to reduce your exposure to them, you may want to check out my PFAS Masterclass. It’s a 5-day, email-based mini course which will tell you everything you need to know about PFAS in a digestible way.
Although PFAS exposure is difficult (read: impossible) to avoid 100%, there is a LOT you can do to decrease exposures for yourself and your family.