People who drank more than one sugar-sweetened beverage a day were more than twice as likely to develop gastric cancer as those who drank less than one a month, according to a study of 112,284 U.S. health professionals.
The study, published in Gastro Hep Advances, drew on the Nurses’ Health Study and the Health Professionals Follow-up Study. Researchers identified 278 cases of gastric adenocarcinoma, including 140 in women and 138 in men, over 3,204,001 person-years of follow-up.
Compared with people who drank less than one sugar-sweetened beverage per month, those who drank more than one 8-ounce serving per day were 2.45 times as likely to develop gastric cancer after researchers accounted for other factors. Gastric cancer was diagnosed in 31 participants over 190,674 person-years in the highest-intake group, compared with 57 participants over 744,034 person-years among those who drank less than one serving a month — roughly 16 vs. eight cases per 100,000 person-years.
The authors reported the association was similar in both cohorts, though the estimate among men was borderline. Women who drank more than one serving daily were three times as likely to develop gastric cancer, while men were two times as likely.
In contrast, drinking artificially sweetened beverages was not linked to the risk of developing gastric cancer, even after researchers accounted for other factors. The authors described the analysis as the first to demonstrate an association between sugar-sweetened beverage intake and gastric cancer incidence.
According to corresponding author Andrew T. Chan, MD, MPH, a gastroenterologist at Harvard Medical School, Boston, the findings are a reminder that diet can influence the risk of cancers beyond those typically associated with it, such as colorectal cancer.
“While more research is needed to confirm this and understand why, cutting back on sugary drinks is a reasonable, low-risk step people can take in the meantime, especially since these drinks have been linked to other chronic health conditions, such as overweight and diabetes,” Dr. Chan told GI & Hepatology News.
For the analysis, Dr. Chan and colleagues began follow-up in 1986, when both groups first reported their beverage intake, and continued through June 2021 for the nurses’ cohort and January 2022 for the men’s cohort. Participants completed food questionnaires every four years and updated information about their lifestyle, medical history, and health every two years. Sugar-sweetened beverages included carbonated beverages, punch, lemonade, and sports drinks, while artificially sweetened beverages included low-calorie carbonated beverages. Researchers accounted for known or possible gastric cancer risk factors, including consumption of red and processed meat.
Researchers also examined Helicobacter pylori infection in a subgroup of 616 women and 324 men with available antibody test results. Infection was found in 36.7% of women and 34.0% of men. Neither sugar-sweetened nor artificially sweetened beverage consumption was linked to H. pylori infection. Higher overall fructose intake was linked to gastric cancer in the full cohort and among women.
Because the study was observational, it cannot prove that sugar-sweetened beverages cause gastric cancer. Other limitations included a lack of detailed information about H. pylori infection, tumor location, family history of gastric cancer, and previous upper endoscopy. Most participants were white and between ages 30 and 75 when they joined the study, so researchers could not examine findings across racial and ethnic groups or younger adults.
For clinicians, the findings suggest that frequent consumption of sugar-sweetened beverages may be a dietary sign of higher gastric cancer risk. However, Dr. Chan and his coauthors said more research is needed to confirm the association and determine whether sugary drinks directly contribute to gastric cancer. Possible explanations include weight gain, insulin resistance, steroid hormone imbalance, inflammation, DNA damage, and changes in the gut microbiome.
National Cancer Institute grants and a Stand Up to Cancer Gastric Cancer Interception Dream Team award funded the study. Dr. Chan reported consulting for Pfizer and Boehringer Ingelheim and grant support from Freenome Holdings outside the submitted work. The other authors reported no conflicts of interest.
Expert Insight
Dr. Chan shared his take on the findings with GI & Hepatology News.
Do your findings support counseling patients to limit SSB intake specifically for gastric cancer prevention, or is it too early to make that clinical recommendation?
Dr. Chan: Most people who drink sugary beverages could choose to cut back or substitute something else. If this association holds up in future research, it means there may be a meaningful, actionable way for people to lower their risk of a cancer that is often diagnosed late and is difficult to treat.
Because H. pylori status was available only for a subset, how confident are you that the observed SSB–gastric cancer association is independent of H. pylori infection?
Dr. Chan: It was reassuring that our findings held up even when accounting for H. pylori infection in a subset of our population. However, future studies are needed to look at this more carefully with a larger sample size.
Could the lack of tumor location data be masking clinically important differences in the association between SSB intake and cardia vs. non-cardia gastric cancers?
Dr. Chan: We don’t know if our association is the same for both cardia vs. non-cardia gastric cancer. This also requires further research.
Is there anything else you’d like to say about this work?
Dr. Chan: We don't yet know the precise mechanism, but several biological pathways have been proposed for how these beverages might contribute to cancer risk generally, including their effects on weight gain, insulin resistance, chronic inflammation, and changes to the gut microbiome. Any or several of these could plausibly play a role in stomach cancer specifically.