Study details and key findings

In the United States, 63% of adults ages 18 and older report drinking sugar-sweetened beverages, like regular soda, energy drinks, and juice with added sugars, at least one or more times a day. Previous studies have linked the consumption of sugar-sweetened beverages with an increased risk of colorectal, breast, and liver cancers, but evidence on gastric or stomach cancer has been limited.

For the study, researchers from Mass General Brigham Cancer Institute analyzed data from 112,284 participants who were part of the Nurses' Health Study and the Health Professionals Follow-Up Study. The studies collected detailed information about participants' diet, lifestyle, and health information over several decades.

During the follow-up period, 278 participants developed stomach cancer. After accounting for other potential risk factors, the researchers found that participants who had least one serving of a sugar-sweetened beverage a day had a 2.45 times greater risk of stomach cancer compared to those who consumed less than one serving a month.

Fructose is the main sweetener used in these beverages, and higher total fructose intake was associated with greater stomach cancer incidence. The association between sugar-sweetened beverages and stomach cancer was observed in both men and women.

However, the researchers did not find a link between consuming artificially sweetened beverages and stomach cancer. 

Commentary

Anton Bilchik, a surgical oncologist, chief of medicine, and director of gastrointestinal and hepatobiliary program at Providence Saint John's Cancer Institute, said it was alarming that a single sugar-sweetened drink a day was associated with such an increase in stomach cancer risk.

Although the reason why sugar-sweetened beverages may contribute to this increased risk is still unknown, Bilchik suggested that insulin resistance and inflammation could both play a role.

"[W]hether sweetened drinks cause or result in increased inflammation and then stomach cancer is yet to be studied. So several possible explanations, but the bottom line is we just don't know," Bilchik said.

Chan acknowledged that more research is needed to confirm the association between sugar-sweetened beverages, as well as potentially identify the biological mechanism behind the association. In the meantime, he noted that "cutting back on sugary drinks is reasonable, low-risk step people can take" to reduce their risk of stomach cancer.

"Reducing consumption of these beverages is also associated with benefits in prevention of other chronic diseases, such as diabetes and obesity," Chan added.

Meridan Zerner, a registered dietitian and founder of Meridan Zerner Nutrition, recommends people make one swap a day if they want to cut back on the amount of sugar-sweetened beverages they drink.

For example, you could switch your afternoon soda or sweet tea with sparkling water or unsweetened iced tea. You could also mix unsweetened tea with sweet tea or sparking water with soda to gradually reduce the amount of sugar you consume.

"Appreciating that change can be challenging — give yourself permission to taper rather than quit abruptly," Zerner said.