A recent study conducted by the Southern California Superfund Research and Training Program for PFAS Assessment, Remediation and Prevention (ShARP) Center in collaboration with the University of Hawai'i has found a link between exposure to certain "forever chemicals" and an increased risk of liver disease in adolescents. These substances, known as per- and polyfluoroalkyl substances (PFAS), are synthetic compounds used in products such as nonstick cookware, water-repellent fabrics, food packaging, and some cleaning agents. They persist in the environment and accumulate in human bodies over time.
The research indicates that adolescents exposed to higher levels of PFAS may be up to three times more likely to develop metabolic dysfunction-associated steatotic liver disease (MASLD), formerly referred to as fatty liver disease. MASLD is a chronic condition that can occur without clear symptoms but increases the long-term risk for several serious health issues including type 2 diabetes, heart disease, advanced liver injury, cirrhosis, and liver cancer.
Lida Chatzi, MD, PhD, professor at the Keck School of Medicine of USC and director of the ShARP Center, stated: "MASLD can progress silently for years before causing serious health problems. When liver fat starts accumulating in adolescence, it may set the stage for a lifetime of metabolic and liver health challenges. If we reduce PFAS exposure early, we may help prevent liver disease later. That's a powerful public-health opportunity."
More than 99% of people living in the United States have detectable levels of PFAS in their blood. At least one type of PFAS has been found in about half of U.S. drinking water sources.
Shiwen "Sherlock" Li, PhD, assistant professor at the University of Hawai'i and lead author on the study said: "Adolescents are particularly more vulnerable to the health effects of PFAS as it is a critical period of development and growth. In addition to liver disease, PFAS exposure has been associated with a range of adverse health outcomes, including several types of cancer."
The study analyzed data from 284 adolescents and young adults from two longitudinal studies based at USC. Participants had an increased metabolic risk due to parental history of type 2 diabetes or overweight status. Researchers measured participants' blood for PFAS levels and used MRI scans to assess liver fat.
Findings showed that higher concentrations of perfluorooctanoic acid (PFOA) and perfluoroheptanoic acid (PFHpA)—two common types of PFAS—were linked to greater odds of MASLD diagnosis among adolescents. Those with double the amount of PFOA were nearly three times more likely to have MASLD compared to peers with lower exposure. The association was even stronger among individuals carrying a specific genetic variant known as PNPLA3 GG; smoking further heightened risk among young adults.
Max Aung, PhD, MPH from Keck School commented: "These findings suggest that PFAS exposures, genetics and lifestyle factors work together to influence who has greater risk of developing MASLD as a function of your life stage. Understanding gene and environment interactions can help advance precision environmental health for MASLD."
Li added that this is the first study investigating links between PFAS exposure and MASLD in children using established diagnostic criteria while also examining how genetics or lifestyle choices interact with chemical exposures.
The research builds on earlier work by USC indicating that high levels of certain PFAS are associated with worse forms of liver disease—including inflammation and fibrosis—in obese adolescents undergoing bariatric surgery.
Chatzi concluded: "Taken together, the two studies show that PFAS exposures not only disrupt liver biology but also translate into real liver disease risk in youth. Adolescence seems to be a critical window of susceptibility, suggesting PFAS exposure may matter most when the liver is still developing."
This study received funding from several sources including multiple grants from the National Institutes of Health, support from the U.S. Environmental Protection Agency (EPA), and contributions from the Hastings Foundation.
