One Sugary Drink a Day Was Tied to Double the Risk of Stomach Cancer

Anyone who has spent time researching stubborn stomach or gut symptoms has probably run across the short list of gastric cancer risk factors, H. pylori infection, smoking, heavy alcohol use. A new study adds a familiar daily habit to that list. Researchers tracking more than 112,000 US adults for over three decades found that people who drank a sugar-sweetened beverage at least once a day had close to double the risk of developing gastric cancer compared with those who rarely drank them, a link that held even after accounting for red and processed meat intake, weight, and other known risk factors. Diet versions of the same drinks showed no such association.

Key takeaways

• People who drank sugar-sweetened beverages (regular soda, sports drinks, punch, lemonade) at least once a day had roughly double the rate of gastric cancer compared with people who almost never drank them.
• Diet and other artificially sweetened beverages showed no link to gastric cancer risk in this study.
• The study can't prove sugary drinks cause gastric cancer, it's an association from observational data, and the actual number of cases stayed small.
• Researchers point to dysbiosis (an imbalance in gut bacteria), along with weight gain and chronic inflammation, as possible biological pathways connecting sugary drinks to cancer risk.

Daily Sugary Drinks Linked to Higher Gastric Cancer Risk

People who drank at least one sugar-sweetened beverage (SSB), meaning regular soda, sports drinks, punch, or lemonade, every day had a 2.45-fold higher rate of gastric cancer than people who almost never drank them, after adjusting for known risk factors like smoking, alcohol, and meat intake, according to a new cohort study published in Gastro Hep Advances. The finding comes from a joint analysis of two of the longest-running health studies in the US, the Nurses' Health Study and the Health Professionals Follow-up Study, led by researchers at Massachusetts General Hospital and Harvard Medical School. Among 112,284 participants tracked for more than three decades, 278 people developed gastric cancer. Artificially sweetened beverages (ASB), like diet soda, showed no meaningful link to gastric cancer risk in the same analysis.

Who Faces the Highest Stakes From This Finding

Gastric cancer is already the fourth leading cause of cancer death worldwide, according to a 2023 review in Nature Reviews Clinical Oncology, and it's notoriously hard to catch early because symptoms like indigestion, bloating, or mild stomach pain overlap with far more common, benign conditions. That overlap is exactly why people who suspect a gut issue often end up researching cancer risk factors in the first place. The new data matters most for anyone already carrying other risk factors, a history of H. pylori infection, a family history of stomach cancer, or a diet heavy in salted, pickled, or charred foods, since the study suggests daily sugary drinks may compound that baseline risk rather than act alone. The effect showed up in both sexes. Women in the Nurses' Health Study who drank SSBs daily had roughly triple the risk (HR 3.04) of those who rarely did, while men in the Health Professionals Follow-up Study saw about double the risk (HR 1.99).

Inside the Three-Decade Nurses and Health Professionals Cohorts

The strength of this study is its design and its size. Researchers pooled data from the Nurses' Health Study, which enrolled 121,700 female nurses starting in 1976, and the Health Professionals Follow-up Study, which enrolled 51,529 male health professionals starting in 1986. Both groups filled out detailed food frequency questionnaires every four years starting in 1986, tracking exactly how often they drank sugary sodas, sports drinks, and diet beverages, then answered health surveys every two years for decades afterward. That design lets researchers watch beverage habits and cancer diagnoses unfold together in real time, rather than relying on people's memory of what they drank years earlier. Across 3.2 million person-years of follow-up, the team confirmed each gastric cancer diagnosis using medical records or cancer registries rather than self-report alone, which strengthens confidence in the outcome data even though the total case count stayed modest.

What This Means If You Drink Soda Daily

This isn't a reason to panic over an occasional soda, and the researchers aren't recommending anyone switch to diet drinks as a proven protective step either, since ASBs simply showed no measurable effect either way rather than a benefit. Artificially sweetened beverages carry their own open questions, the WHO's International Agency for Research on Cancer classified aspartame as a possible carcinogen in 2023 based on limited evidence for liver cancer specifically, a separate question from what this new gastric cancer study measured. What the data does support is treating daily sugary drink habits as one more modifiable risk factor worth mentioning to a doctor, especially for anyone who already has a personal or family history of gastric issues, H. pylori infection, or stomach cancer. The researchers also flagged a related finding, high fructose intake specifically (the primary sweetener in SSBs) was linked to gastric cancer risk on its own, which points toward the sugar itself rather than the carbonation or caffeine in soda as the more likely driver. For a self-directed reader, the practical takeaway is straightforward, cutting back on daily sugary drinks is a reasonable, low-risk step that lines up with general metabolic and heart-health advice regardless of what future gastric cancer research finds.

What the Study Cannot Yet Prove

This is an observational cohort study, so it can show a statistical association but can't prove that sugary drinks directly cause gastric cancer. The researchers themselves note several open gaps. Only a small subset of participants, 940 out of 112,284, had their H. pylori infection status directly tested, so the analysis couldn't fully separate the effect of sugary drinks from this dominant, well-established risk factor across the full cohort. Both cohorts were also predominantly White health professionals first enrolled between ages 30 and 75, so the findings may not translate cleanly to more racially diverse populations or to younger adults. The study also could not examine where in the stomach each cancer developed, or capture family history and prior endoscopy history, all factors that shape individual risk. Finally, one of the paper's senior authors has disclosed consulting work for pharmaceutical companies Pfizer and Boehringer Ingelheim, unrelated to this study, a standard disclosure worth noting even though it has no direct bearing on a diet and cancer analysis funded by the National Institutes of Health.

What Researchers Want to Study Next

The authors call this the first study to demonstrate a link between sugar-sweetened beverage intake and gastric cancer incidence in a US population, and they're direct about what comes next, confirming the finding in other cohorts and pinning down the biology behind it. This isn't the first time sugary drinks have been tied to cancer in a major US cohort. A 2023 JAMA analysis of nearly 100,000 postmenopausal women found that daily sugar-sweetened beverage intake was linked to a higher risk of liver cancer, and a separate Nurses' Health Study analysis published in Gut linked sugary drink intake in adolescence and adulthood to early-onset colorectal cancer in women. Together with the new gastric cancer findings, that's a growing pattern across different digestive organs pointing at added sugar specifically, not just excess calories. Several mechanisms are on the table for gastric cancer specifically, including weight gain, insulin resistance, hormonal shifts, chronic inflammation, DNA damage, and dysbiosis (an imbalance in the gut's bacterial community that's increasingly tied to digestive cancers). None of those pathways has been confirmed as the actual driver here, and the researchers describe the underlying biology as still unexplored.

Common Questions

Does diet soda increase gastric cancer risk?

No. In this study, people who drank artificially sweetened beverages daily showed no meaningful increase in gastric cancer risk compared with those who rarely drank them.

How much does daily sugary drink consumption raise gastric cancer risk?

People who drank a sugar-sweetened beverage at least once a day had roughly 2.45 times the rate of gastric cancer compared with people who almost never drank them, after adjusting for other risk factors.

What is the connection between gut bacteria and this finding?

The researchers list dysbiosis, an imbalance in gut bacteria, as one of several possible biological pathways linking sugary drinks to cancer risk, alongside inflammation and insulin resistance, though this study didn't directly measure microbiome changes.

Is this study enough to prove sugary drinks cause gastric cancer?

No. It's an observational study that shows a statistical association, not a proven cause and effect relationship, and the researchers say the finding needs to be confirmed in other populations.

References

1. Tae-Geun Gweon, Jane Ha, Hanseul Kim, Mengxi Du, Mingyang Song, Andrew T. Chan (2026). Association between sugar-sweetened and artificially sweetened beverage intake and gastric cancer incidence. Gastro Hep Advances. https://doi.org/10.1016/j.gastha.2026.101097
2. Aaron P. Thrift, Theresa Nguyen Wenker, Hashem B. El-Serag (2023). Global burden of gastric cancer: epidemiological trends, risk factors, screening and prevention. Nature Reviews Clinical Oncology. https://doi.org/10.1038/s41571-023-00747-0
3. Sweetened Beverages and Risk of Adverse Liver Outcomes. JAMA Network. https://jamanetwork.com/journals/jama/fullarticle/2807987
4. Jinhee Hur, Ebunoluwa Otegbeye, Hee-Kyung Joh, et al. (2021). Sugar-sweetened beverage intake in adulthood and adolescence and risk of early-onset colorectal cancer among women. Gut. https://doi.org/10.1136/gutjnl-2020-323450