Sugary drinks have been linked to weight gain, type 2 diabetes and other health concerns. A new study suggests there may be another reason to pay attention to how often they show up in your routine: liver health.
In a pooled analysis of 11 long-running studies, researchers found that each additional sugar-sweetened beverage consumed per day was associated with a 10% higher risk of hepatocellular carcinoma, the most common type of liver cancer, and a 15% higher risk of intrahepatic cholangiocarcinoma, a cancer that begins in the bile ducts inside the liver. The study was observational, meaning it cannot prove that sugary drinks directly caused the increased risk.
The researchers did not find a statistically significant association between sugar-sweetened drinks and liver cancer overall. The associations emerged when they examined the two cancer subtypes separately. Artificially sweetened beverage intake was not independently associated with liver cancer overall or with either subtype after the researchers accounted for factors that could influence risk.
Published in JAMA Network Open, the analysis included 1,518,411 adults from 10 U.S. studies and one European study. Participants were followed for a median of nearly 18 years. During that time, researchers identified 2,811 liver cancer cases, including 1,699 cases of hepatocellular carcinoma and 444 cases of intrahepatic cholangiocarcinoma.
The study adds a new layer to the conversation about sweetened drinks. Sugar-sweetened beverages are already associated with health conditions that can increase liver cancer risk, including obesity, type 2 diabetes and metabolic dysfunction-associated steatotic liver disease, sometimes called fatty liver disease. The researchers adjusted for body mass index and diabetes status, among other factors, but acknowledged that they could not fully determine whether sugary drinks were associated with liver cancer independently of obesity and diabetes.
There also may be other ways sugary drinks affect the liver. Fructose, one of the sugars commonly found in sweetened beverages, is primarily metabolized in the liver. Previous research has linked higher sugar intake with greater fat accumulation in the liver. However, the new study did not test the biological mechanisms behind the cancer associations.
The findings involving artificially sweetened beverages require their own careful interpretation. In 2023, the International Agency for Research on Cancer classified aspartame as “possibly carcinogenic to humans” based on limited evidence, particularly evidence related to hepatocellular carcinoma. At the same time, a separate World Health Organization and Food and Agriculture Organization expert committee reaffirmed its acceptable daily intake for aspartame.
The new analysis did not find evidence that artificially sweetened drinks were independently associated with liver cancer risk after the researchers adjusted for factors such as body mass index and diabetes. People who regularly consumed artificially sweetened drinks were often more likely to have diabetes or a higher body mass index at the beginning of the studies, which can make the relationship difficult to untangle.
That does not mean the study gives artificially sweetened drinks a blanket endorsement. It examined liver cancer risk, not every possible health outcome. It also grouped artificially sweetened beverages together rather than evaluating individual sweeteners, and beverage formulations have changed over time.
The study has other limitations. Participants reported their own beverage intake, and most of the included studies assessed consumption at only one point in time. Drinking habits may change over the years. Researchers were also unable to fully account for underlying liver conditions such as cirrhosis or metabolic dysfunction-associated steatotic liver disease. Information about hepatitis B and hepatitis C infections, which can affect liver cancer risk, was incomplete across the studies.
The participants were also primarily white adults in the United States and Europe. The findings may not apply as clearly to populations in regions where hepatitis infections are a more common driver of liver cancer.
An occasional soda is not the same as a daily habit, and this study does not offer a precise line at which risk changes. But the findings add to the broader evidence that regularly consuming sugary drinks may carry health consequences. Cutting back on routine consumption remains a reasonable step for people looking to support their long-term health.
The study received support from the Canadian Institutes of Health Research, the National Institutes of Health Intramural Program, the Boston University Peter Paul Career Development Professorship and an NIH grant supporting the Southern Community Cohort Study. Two researchers disclosed outside financial relationships unrelated to the submitted work: one reported receiving personal fees from Merck, and another reported receiving equity options from Convergent Therapeutics.