Recent online discussions have raised concerns about whether canned sparkling water could increase the risk of colorectal cancer. Influencers on platforms like Instagram and TikTok have claimed that these beverages, often marketed as a healthier alternative to soda, may contain undisclosed chemicals and elevated levels of per- and polyfluoroalkyl substances (PFAS), also known as "forever chemicals."
Medical experts are addressing these concerns, explaining that the potential link to cancer is not with the carbonated drink itself but with the packaging. Many cans are lined with protective coatings or may be exposed to contaminants like PFAS during manufacturing and packaging. Plastic bottles, another common packaging for beverages, have also been associated with PFAS.
PFAS are "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. However, Dr. Steven Lee-Kong, division chief of colorectal surgery at Hackensack Meridian Health’s Hackensack University Medical Center, notes that the levels found 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 leached from beverage cans is generally considered far below levels shown to cause cancer in experimental studies.
However, experts acknowledge that the science surrounding PFAS and health risks is still evolving. Some health organizations suggest that even very low levels of exposure could pose a risk.
Potential Mechanisms for Cancer Development
According to Abdelrahim, PFAS can potentially contribute to carcinogenesis over long-term exposure by acting as endocrine disruptors, promoting oxidative stress, altering gene expression, or interfering with DNA repair. Additionally, PFAS may disrupt the intestinal barrier, leading to gut inflammation, damage to the intestinal lining, and changes in the gut microbiome over time, as explained by Lee-Kong. There is a known link between chronic inflammation and colorectal cancer, and some PFAS may alter intestinal cells in ways that could promote tumor growth.
"While research is ongoing and some findings are inconsistent, the potential for PFAS to promote gut inflammation and cellular changes is the primary mechanism of concern for colorectal cancer risk," Lee-Kong stated.
Current Understanding and Recommendations
Despite the circulating concerns, experts emphasize that there is currently no direct scientific evidence proving that canned sparkling water or seltzer can cause colon cancer. Abdelrahim stated that "based on current evidence, canned sparkling water is not considered a significant source of PFAS exposure."
More extensive, long-term studies are needed to fully understand the relationship between canned beverages and cancer risk. In the meantime, Lee-Kong advises consumers to drink sparkling water in moderation and diversify their beverage choices. Opting for filtered water is generally the safest and most effective way to stay hydrated.
When choosing canned beverages, Lee-Kong suggests consuming them as part of a balanced and varied diet. Abdelrahim recommends focusing on established, modifiable risk factors for colorectal cancer, such as maintaining a healthy weight, limiting processed and red meat intake, avoiding tobacco, moderating alcohol consumption, staying physically active, and adhering to age-appropriate screening guidelines.
Regulatory organizations like the U.S. Environmental Protection Agency (EPA) are actively investigating the risks associated with PFAS. Staying informed through reliable sources and being mindful of consumption habits are practical steps individuals can take for their long-term health.