Concerns have recently surfaced on social media platforms like Instagram and TikTok, with influencers suggesting that canned sparkling water may increase the risk of colorectal cancer due to undisclosed chemicals and high levels of per- and polyfluoroalkyl substances (PFAS), commonly known as forever chemicals.
Colorectal cancer specialists note that the concern is not with the carbonated beverage itself, but rather with the packaging. Many cans are lined with protective coatings or can be exposed to contaminants, including PFAS, during manufacturing and packaging. Plastic bottles, also frequently used for sparkling water, are similarly linked to PFAS.
PFAS are called "forever chemicals" because they persist in the environment and can accumulate in the human body. Research has linked PFAS exposure to an increased risk of several cancers, including kidney and testicular cancer, as well as impaired immunity, liver damage, infertility, and thyroid disease.
Some studies have detected PFAS in popular sparkling water brands, but Dr. Steven Lee-Kong, division chief of colorectal surgery at Hackensack Meridian Health’s Hackensack University Medical Center, stated that these levels often fall below current federal advisory limits. Dr. Maen Abdelrahim, section chief of Gastrointestinal Medical Oncology at Houston Methodist, added that the dosage of PFAS is critical, and amounts leached from beverage cans are significantly below levels shown to cause cancer in experimental studies. However, Lee-Kong cautioned that the science is still evolving, and some health organizations suggest that even very low levels of exposure could pose a risk.
Regarding how PFAS might contribute to cancer, Abdelrahim explained that these chemicals can act as endocrine disruptors, promote oxidative stress, alter gene expression, or interfere with DNA repair, which could theoretically contribute to carcinogenesis with long-term exposure. Lee-Kong further noted that PFAS may disrupt the intestinal barrier, potentially leading to chronic inflammation, damage to the intestinal lining, and changes in the gut microbiome over time. A well-established link exists between chronic inflammation and colorectal cancer, and some PFAS may alter intestinal cells in a manner that could promote tumor growth.
Despite these potential mechanisms, medical experts currently state there is no direct evidence concluding that canned sparkling water or seltzer causes colon cancer. "Based on current evidence, canned sparkling water is not considered a significant source of PFAS exposure," Abdelrahim said.
More extensive, long-term studies are necessary to fully understand the relationship between canned beverages and cancer risk. In the interim, Lee-Kong advises consumers to be mindful and drink sparkling water in moderation, diversifying beverage choices. He recommends water filtered ideally as the safest and most effective way to stay hydrated. For canned beverages, he suggests consuming them as part of a balanced and varied diet.
Abdelrahim stressed the importance of focusing on well-established, modifiable risk factors for colorectal cancer, such as maintaining a healthy weight, limiting processed and red meat consumption, avoiding tobacco, moderating alcohol intake, staying physically active, and adhering to age-appropriate screening guidelines.
Regulatory organizations, including the U.S. Environmental Protection Agency (EPA), are actively investigating the risks associated with PFAS. Lee-Kong recommended staying informed through reliable sources like the EPA and being mindful of personal consumption habits as practical steps for long-term health.