One Soda a Day Nearly Triples Gastric Cancer Risk in 112,000-Person Study

Roughly 65% of U.S. adults pour themselves at least one sugar-sweetened beverage daily, a habit long tied to obesity, type 2 diabetes, and some cancers. What has been missing from that picture is gastric cancer, the fifth leading cause of cancer death worldwide, a disease whose dietary drivers remain poorly understood. A new study from researchers at the Mass General Brigham Cancer Institute now fills part of that gap, and the findings are striking enough to be worth understanding carefully, even though this kind of research cannot yet prove cause and effect.

Key takeaways:

• Adults drinking at least one sugary beverage daily had 2.45 times the gastric cancer risk of those drinking fewer than one per month.
• Among women specifically, more than one sugary drink per day was linked to a 3.04-fold higher risk.
• Artificially sweetened beverages showed no similar association.
• This is observational research: it identifies a pattern, not a proven cause.
• H. pylori infection status did not appear to explain the association, though the subset studied was small.

Daily SSB consumption linked to more than double the gastric cancer incidence

Participants who drank at least one sugar-sweetened beverage (SSB, meaning carbonated sodas, punch, lemonade, or sports drinks) every day were 2.45 times more likely to develop gastric cancer than those who consumed fewer than one per month, according to the study published in Gastro Hep Advances. Women in the Nurses' Health Study cohort who exceeded one SSB per day faced a still steeper 3.04-fold higher risk. Higher total fructose intake, the primary sweetener in these drinks, was also associated with greater gastric cancer incidence. Artificially sweetened beverages, by contrast, showed no association with gastric cancer risk.

Andrew T. Chan, MD, MPH, who led the research, described the findings as a first for U.S.-based populations: "Gastric cancer is the fifth leading cause of cancer death worldwide, but we've known very little about how diet might contribute to this cancer."

Why people already managing gut health should pay attention

For anyone researching gut-related conditions, gastric cancer sits at one end of a spectrum of diseases shaped partly by what and how we eat. Previous research had already associated SSB intake with higher risks of colorectal, breast, liver, and bile duct cancers. Adding gastric cancer to that list matters because the stomach is where digestion begins, and it is continuously exposed to whatever we swallow. Conditions that inflame or disrupt the stomach lining, including chronic gastritis and H. pylori infection, are established risk factors for gastric cancer. Separately, dietary patterns that include high salt, processed meats, and low intake of fresh vegetables have long been linked to gastric cancer risk in epidemiological research, suggesting the stomach is sensitive to a range of dietary signals over time.

One proposed mechanism here centres on fructose. When you drink a sugary beverage rather than eating whole fruit, liquid fructose is absorbed rapidly because there is no fiber, protein, or fat to slow digestion. Some researchers suspect this fast absorption may drive metabolic and inflammatory changes that promote cancer cell growth, though that pathway has not been established in humans.

How 112,284 adults over several decades powered this finding

The study drew on two long-running U.S. cohorts: the Nurses' Health Study and the Health Professionals Follow-Up Study, together covering 112,284 participants. Both studies collected detailed dietary, lifestyle, and health data over many decades through validated food frequency questionnaires, giving researchers unusually rich data to work with. Over the follow-up period, 278 participants developed gastric cancer. Researchers adjusted for a wide range of potential confounders, including smoking, body weight, alcohol use, and overall diet quality. A subset of 940 participants also had data on H. pylori status (a bacterial infection that is the single largest known risk factor for gastric cancer), which allowed a preliminary look at whether the SSB association was explained by infection rates.

What this could mean if you are watching your own gut health

This research cannot tell any individual whether their beverage habits will cause gastric cancer, and it is not a basis for a specific dietary prescription. What it does is add sugar-sweetened beverages to the list of modifiable risk factors worth discussing with a clinician if gastric health is already a concern for you. The finding that artificially sweetened beverages carried no similar association is notable, and the researchers suggest fructose specifically, rather than sweetness or carbonation, may be the relevant variable. Still, that hypothesis has not been confirmed.

The broader evidence on sugar, obesity, and cancer risk suggests that even when a direct biological mechanism is uncertain, the indirect path through weight gain and metabolic disruption is well established. Reducing daily SSB intake is one of the few dietary changes that has clear support across multiple health outcomes, which gives it value even while the gastric cancer mechanism remains under investigation.

Key gaps: small H. pylori subset and a predominantly white sample

Several limitations shape how confidently we can read these results. The study was observational, so it can identify associations, not prove that SSBs cause gastric cancer. Higher consumption might correlate with other unmeasured behaviours that carry the real risk. The H. pylori subset of 940 participants was too small to draw firm conclusions about whether infection status modifies the SSB-cancer relationship. Family history of gastric cancer was also not well captured. Most significantly, participants were predominantly white, which limits whether findings generalise across racial and ethnic groups that have meaningfully different gastric cancer rates. The National Cancer Institute notes that even well-established dietary associations with gastric cancer have not yet clearly translated into confirmed prevention strategies when studied in trials, a caution that applies here too.

What comes next for SSB and gastric cancer research

The authors call for further studies to confirm the association and, critically, to investigate the biological mechanisms, particularly the role of fructose metabolism in gastric tissue. Research in more diverse populations is also needed. Until that work is done, the current findings sit in the emerging category: a credible and concerning signal from a large, well-designed cohort study, but not yet the kind of replicated, mechanistically understood evidence that translates into clinical guidelines.

Common questions

Does this mean diet soda is safe for the stomach? In this study, artificially sweetened beverages were not associated with increased gastric cancer risk, which suggests fructose or calories, rather than sweetness alone, may be the relevant factor. That said, the study was not designed to establish that diet drinks are safe in any absolute sense.

Does H. pylori infection change my risk if I also drink sugary beverages daily? The study looked at this question in a subset of 940 participants and found no clear interaction, but that subset was too small to draw firm conclusions. H. pylori remains the single largest known modifiable risk factor for gastric cancer regardless of beverage habits.

How many sugary drinks is too many, according to this research? The elevated risk appeared in people consuming at least one SSB per day compared with those drinking fewer than one per month. The study did not establish a safe threshold below that level.

Should I ask my doctor about this if I have a stomach condition? If you are already managing chronic gastritis, a family history of gastric cancer, or a known H. pylori infection, this finding is worth raising with your gastroenterologist as part of a broader conversation about diet and risk, without treating it as a confirmed causal link.

References

1. Ke Pu, Yang Feng, Qian Tang, Guodong Yang, Chuan Xu (2024). Review of dietary patterns and gastric cancer risk: epidemiology and biological evidence. Frontiers in Oncology. https://doi.org/10.3389/fonc.2024.1333623
2. Stomach Cancer Prevention | Winship Cancer Institute of Emory University. winshipcancer.emory.edu. https://winshipcancer.emory.edu/cancer-care/types-of-cancer/stomach-cancer/prevention.html
3. Margeaux Epner, Peiying Yang, Richard W. Wagner, Lorenzo Cohen (2022). Understanding the Link between Sugar and Cancer: An Examination of the Preclinical and Clinical Evidence. Cancers. https://doi.org/10.3390/cancers14246042
4. Stomach (Gastric) Cancer Prevention (PDQ®) – NCI. cancer.gov. https://www.cancer.gov/types/stomach/patient/stomach-prevention-pdq