One Sugary Soda a Day Linked to Higher Liver Cancer Risk, Study Finds

If you've been chasing down a gut-health lead for a liver problem, "cut the soda" has probably come up before, usually as vague advice with no numbers attached. A new pooled analysis of over 1.5 million people finally puts a number on it: drinking one sugar-sweetened beverage a day is tied to a measurable rise in risk for two specific liver cancer subtypes. The findings also answer a question that comes up early for anyone trying to sort out what actually matters, that diet soda didn't carry the same signal, and point to the gut as the likely reason why.

Key takeaways

• Drinking one sugar-sweetened beverage (SSB) per day was linked to a 10% higher risk of hepatocellular carcinoma (HCC) and a 15% higher risk of intrahepatic cholangiocarcinoma (ICC), the two main liver cancer subtypes, in a pooled analysis of 1.5 million people.
• Artificially sweetened (diet) beverages showed no link to liver cancer risk once the researchers accounted for body weight and diabetes.
• The leading explanation is a gut mechanism, not a direct liver effect, fructose may loosen the gut's barrier, letting bacterial byproducts leak into the bloodstream and reach the liver, but this study did not measure gut permeability directly.
• This is observational data: it shows a pattern, not proof that soda causes liver cancer, and it can't fully rule out undiagnosed liver disease as a confounder.

Sugar-Sweetened Beverages Linked to Two Liver Cancer Subtypes

Each additional sugar-sweetened beverage consumed per day was associated with a 10% higher risk of hepatocellular carcinoma (HCC, cancer that starts in the liver's main cells) and a 15% higher risk of intrahepatic cholangiocarcinoma (ICC, a rarer cancer that starts in the liver's bile ducts), according to a pooled analysis of 11 long-running cohort studies published in JAMA Network Open in June 2026. The HCC risk increase (hazard ratio 1.10, 95% CI 1.03-1.18) and the ICC risk increase (hazard ratio 1.15, 95% CI 1.00-1.32) were both calculated per one-beverage-per-day increment, meaning the more SSBs someone typically drank, the higher their modeled risk climbed. Liver cancer overall, when HCC and ICC were combined into one category, did not reach statistical significance after the researchers adjusted for other risk factors, a reminder that the SSB signal shows up more clearly when the two subtypes are looked at separately. Artificially sweetened beverages (ASBs), by contrast, showed no association with either subtype or with liver cancer overall once body mass index and diabetes were factored in.

Why This Matters for Anyone Managing Metabolic or Liver Risk

This finding is relevant well beyond people who already have a liver diagnosis. Anyone managing insulin resistance, type 2 diabetes, obesity, or metabolic dysfunction-associated steatotic liver disease (MASLD, the fatty liver condition linked to diet and inactivity, formerly called NAFLD) has extra reason to pay attention, since these conditions independently raise liver cancer risk and may compound whatever effect SSBs are contributing. The study's authors frame this as adding to a growing body of evidence, not a single alarm bell, that treats sugary drinks as one modifiable piece of long-term liver cancer risk, alongside established drivers like alcohol use and viral hepatitis.

A Pooled Analysis of 1.5 Million People Followed for Nearly 18 Years

The researchers combined data from 11 prospective cohorts across the US and Europe, including well-known long-term studies like the Nurses' Health Study and the NIH-AARP Diet and Health Study, to reach a combined sample of 1,518,411 participants (average age 57.8, 58.2% women). Over a median follow-up of 17.8 years, researchers tallied 2,811 confirmed liver cancer cases: 1,699 HCC and 444 ICC. Pooling cohorts this way, rather than relying on one study, is what let the researchers detect a risk difference of this size for ICC, a cancer rare enough that most single studies don't record enough cases to say anything statistically meaningful about it. Diet was self-reported once at the start of each cohort using food-frequency questionnaires, then tracked forward against cancer registries and death records for years afterward.

What This Means If You Drink Soda Regularly

Nothing here means an occasional soda is dangerous, or that liver cancer is an inevitable outcome of drinking one SSB a day. The risk increases reported are relative and modest in absolute terms: liver cancer itself remains uncommon, and a 10-15% relative increase per daily beverage moves individual risk only slightly for most people. What it does support is treating regular sugary drink consumption as one more lever worth pulling if you're already managing metabolic risk, alongside, not instead of, standard care for diabetes, weight, alcohol use, and hepatitis screening. If you already have a fatty liver diagnosis or elevated liver enzymes, this is a reasonable finding to bring up at your next appointment, particularly if soda is a daily habit. Diet soda did not carry the same signal here, which is useful information if you're deciding what to switch to, but it isn't the same as a clean bill of health for artificial sweeteners on other measures the study didn't examine.

What the Study Can't Prove

This is observational research, so it can show a pattern without proving sugar-sweetened beverages cause liver cancer. Diet was captured through self-report, which is always subject to error, and measured just once at each cohort's start rather than tracked over the following 17.8 years, so it can't capture how people's drinking habits actually changed over time. The researchers also couldn't fully account for underlying liver disease like MASLD or cirrhosis at baseline, or complete hepatitis B and C status across all 11 cohorts, both of which are major independent drivers of liver cancer that could be tangled up with the SSB association. The pooled cohorts were also primarily White participants, which limits how confidently the findings generalize to other populations. Two of the study's co-authors disclosed unrelated industry ties (consulting fees and equity in companies unconnected to soda or this specific finding), a standard disclosure that doesn't implicate the result itself.

The Gut Mechanism Behind the Numbers, and Where the Research Goes Next

The study's authors point to a specific biological pathway to explain why sugar, and not artificial sweeteners, might matter: fructose, they write, "can contribute to bacterial overgrowth and disrupt tight junctions in the gut, therefore increasing gut permeability and endotoxin exposure from the portal vein." In plain terms, high fructose intake may loosen the seals between the cells lining the intestine (tight junctions), letting bacterial byproducts called endotoxins leak into the bloodstream and travel directly to the liver through the portal vein, the blood vessel that carries everything absorbed from the gut. That leak can trigger chronic low-grade inflammation in the liver, a process independently linked to fatty liver disease and, over time, cancer. It's worth being precise about what this study did and didn't do: the authors are describing a plausible mechanism based on existing biology, not something they measured directly in these 1.5 million participants. Separate lab research, including a 2019 Hepatology study that found fructose reduced gut tight-junction proteins and raised bacterial endotoxin levels in animal models, and a related UC San Diego Health research summary on excess fructose weakening the gut barrier, supports the biological plausibility of that pathway. A 2023 Women's Health Initiative study previously found a similarly elevated liver cancer risk among postmenopausal women who drank sugary beverages daily.

Common Questions

Does diet soda carry the same liver cancer risk as regular soda? No. In this analysis, artificially sweetened beverages showed no association with liver cancer risk once body weight and diabetes were accounted for, unlike sugar-sweetened beverages.

How much does one soda a day actually raise liver cancer risk? The study found each additional sugar-sweetened beverage per day was linked to a 10% higher relative risk of HCC and a 15% higher relative risk of ICC, the two main liver cancer subtypes, not an absolute risk that applies the same way to everyone.

Does this study prove sugar-sweetened beverages cause liver cancer? No. It's an observational pooled analysis, which can show a strong association but can't establish cause and effect the way a controlled trial could.

Who should pay closest attention to this finding? People managing insulin resistance, type 2 diabetes, obesity, or an existing fatty liver diagnosis (MASLD), since these conditions already raise liver cancer risk independently of soda intake.

References

1. Artificially Sweetened and Sugar-Sweetened Beverage Intake and Risk of Liver Cancer. JAMA Network. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2850133
2. Young‐Eun Cho, Do‐Kyun Kim, Wonhyo Seo, Bin Gao, Seong‐Ho Yoo, Byoung‐Joon Song (2019). Fructose Promotes Leaky Gut, Endotoxemia, and Liver Fibrosis Through Ethanol‐Inducible Cytochrome P450‐2E1–Mediated Oxidative and Nitrative Stress. Hepatology. https://doi.org/10.1002/hep.30652
3. Excessive Fructose Consumption May Cause a Leaky Gut, Leading to Fatty Liver Disease. health.ucsd.edu. https://health.ucsd.edu/news/press-releases/2020-08-24-excessive-fructose-consumption-may-cause-leaky-gut/
4. Association Between Sugar-Sweetened Beverage Intake and Liver Cancer Risk in the Women's Health Initiative. NIH. https://pmc.ncbi.nlm.nih.gov/articles/PMC9193518/