SOMERVILLE, Mass., Aug. 20 (Nationwide Times) — A U.S. study found that people who drank at least one sugar-sweetened beverage a day had 2.45 times the risk of developing stomach cancer as people who drank fewer than one serving a month.
The finding is an association, not proof that soda or other sugary drinks cause cancer. The study’s senior author, Andrew T. Chan of Mass General Brigham and Massachusetts General Hospital, said the research could not establish cause and effect and that more research is needed.
The result also does not show that a person who drinks a sugary beverage daily will develop stomach cancer. The study recorded 278 cases among 112,284 participants over several decades, but the researchers did not report in the supplied study summary the absolute risk for each beverage-consumption group. That means the relative-risk figure cannot be used to determine an individual’s personal risk.
What did the study examine?
Researchers analyzed information from two long-running U.S. studies: the Nurses’ Health Study and the Health Professionals Follow-Up Study. The data covered 1986 through 2022, according to the study summary published by Mass General Brigham.
The researchers examined consumption of sugar-sweetened beverages, including carbonated drinks, punch, lemonade and sports drinks. The study’s analysis also considered total fructose intake, a type of sugar found in many sweetened foods and drinks.
The comparison was between participants who consumed at least one sugar-sweetened beverage each day and those who consumed fewer than one serving per month. The serving definition in the study materials was 8 ounces.
What does “2.45 times the risk” mean?
The figure is a relative-risk comparison. It describes how the two groups differed within the study; it does not mean that 245 out of every 100 people who drink a sugary beverage daily will get stomach cancer.
Because the study summary does not provide the absolute risk for each group, the size of the difference in actual percentage points cannot be calculated from the available information. The total number of documented cases was small compared with the full study population.
Were the findings the same for everyone?
The association appeared in both women and men, according to the study reports. Among women in the Nurses’ Health Study, consuming more than one sugar-sweetened beverage per day was associated with a 3.04-fold higher risk compared with very rare consumption.
The study also found that higher total fructose intake was associated with a higher incidence of stomach cancer. That result does not establish whether fructose itself caused the cancer or whether it reflected other dietary or lifestyle factors connected with higher fructose consumption.
The researchers adjusted for other potential risk factors, according to Mass General Brigham. The supplied study summary does not list all of those factors or provide the study’s confidence intervals and full statistical model.
What about diet drinks?
The analysis found no association between higher consumption of artificially sweetened beverages and increased stomach-cancer incidence after adjustment for other factors. In the study, those beverages were defined as low-calorie carbonated drinks.
That finding does not show that artificially sweetened beverages reduce cancer risk. It indicates only that the study did not observe an increased incidence associated with them after the analysis accounted for other factors.
Why are more studies needed?
The research was observational. That means the investigators studied patterns in existing health and diet data rather than assigning people to drink particular beverages. Observational studies can identify associations, but they cannot by themselves prove that one exposure caused an outcome.
The study also cannot determine from the supplied results whether the association was caused specifically by sugary beverages, fructose, another part of participants’ diets or a related factor. Chan said the finding was the first reported association between sugar-sweetened beverage intake and stomach cancer in a U.S. population, but he also said further research is needed to determine whether the relationship is truly causal.
The study was published in Gastro Hep Advances by researchers identified by Mass General Brigham as Gweon T.G. and colleagues.
