- A new large study suggests that daily sugary drink consumption is linked to a higher risk of developing stomach cancer, compared with those who drink them less than once a month.
- In particular, a higher consumption of fructose, a sugar commonly found in these beverages, was associated with a greater incidence of stomach cancer.
- However, as an observational study, the findings cannot establish that sugary drinks directly cause stomach cancer. Other factors, such as bacterial infections, diet, weight, and other lifestyle choices, may also influence risk.
Sugar-sweetened beverages, such as regular soft drinks, sweetened teas and coffees, sports and energy drinks, and fruit drinks, are a
Older data from the
Regular consumption of these beverages is associated with a range of adverse health outcomes, including weight gain, obesity, type 2 diabetes, and cardiovascular disease. There is also growing interest in a possible relationship between high consumption of sugary beverages and cancer.
Now, a large observational study suggests that people who regularly consume sugar-sweetened beverages may have a 2.45-fold higher risk of developing stomach cancer.
The findings, published in Gastro Hep Advances, add to growing research indicating that the consumption of sugary drinks may contribute to cancer risk. However, as an observational study, it cannot establish that sugary drinks directly cause stomach cancer.
What did the study find?
Researchers from Mass General Brigham analyzed dietary and health information from more than 112,000 US adults drawn from two long-running US studies: the Nurses’ Health Study and the Health Professionals Follow-up Study.
Participants were grouped according to how frequently they reported consuming sugar-sweetened beverages. These included carbonated beverages, punch, lemonade, and sports drinks. Over the course of follow-up, 278 participants developed stomach cancer, also known as gastric cancer.
Compared with people who consumed fewer than one sugar-sweetened beverage per month, those drinking these beverages daily had more than twice the risk of developing gastric cancer after the researchers accounted for a range of potential risk factors.
The association appeared particularly strong among females who consumed more than one sugar-sweetened beverage per day. The study also found that higher total intake of fructose was associated with a greater incidence of gastric cancer.
“Based on data collected from more than 100,000 people over decades, we found that consuming at least one sugar-sweetened beverage per day was associated with more than twice the risk of developing gastric cancer compared with those never consumed these beverages,” senior study author Andrew Chan, MD, MPH, a gastroenterologist and epidemiologist with the Mass General Brigham Cancer Institute, told Medical News Today.
“In contrast, artificially sweetened beverages were not associated with increased risk of gastric cancer,” he said.
Sugar vs. artificial sweeteners
“(T)he evidence on artificial sweeteners and cancer risk overall is still evolving and somewhat mixed. The insulin and metabolic pathways that might underlie the risk of stomach cancer are specific to sugar sweetened beverages and not artificially sweetened beverages.”
—Andrew Chan, MD, MPH
Why might sugary drinks be associated with stomach cancer?
While the study found an association, it was not designed to determine why sugar-sweetened beverages might be associated with stomach cancer, so any explanation remains speculative.
One possibility is that frequent consumption of sugary drinks may contribute to weight gain and metabolic changes. Previous research highlights an association between excess body weight and an increased risk of several cancers. However, the relationship between obesity and individual cancer types can be complex.
“We don’t know the exact 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,” said Chan.
“Any or several of these could plausibly play a role in stomach cancer specifically,” he added.
Could fructose play a role?
The researchers also note an association between higher fructose intake and gastric cancer incidence. Evidence suggests that high-fructose corn syrup may play a role in chronic inflammation and tumor development. However, the study findings do not prove that fructose itself causes stomach cancer.
“Intriguing data suggest that fructose in particular may play a specific role in cancer development,” Chan said. “This may be due to insulin or inflammatory pathways, but also some metabolic pathways specific to cancer.”
The research team also add that certain lifestyle factors, such as dietary choices, smoking, and alcohol consumption likely play a role and it is difficult to account for these factors in observational research.
What does this mean for people who drink sugary beverages?
The study’s finding of a 2.45-fold higher risk may sound alarming, but it does not necessarily mean that someone who drinks soda occasionally is likely to develop stomach cancer.
Although the findings note more than twice the risk of developing stomach cancer, this is a measure of
While those who regularly consumed sugar-sweetened beverages had roughly a 145% higher relative risk of stomach cancer, there were 278 cases of gastric cancer among 112,284 participants during the study period, suggesting stomach cancer was relatively uncommon in this population.
Still, the findings add to
“Regularly drinking sugar-sweetened beverages appears to be associated with a significantly higher risk of stomach cancer,” Chan told MNT.
“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. Reducing consumption of these beverages is also associated with benefits in prevention of other chronic diseases, such as diabetes and obesity.”
—Andrew Chan, MD, MPH
Tips for reducing sugar-sweetened beverage intake can include swapping them for water or unsweetened varieties.
Alternatively, people can gradually taper these drinks by mixing soda with sparkling water. Individuals may also read the packaging label and choose a low sugar or sugar-free option, or avoid those containing added sugars such as high-fructose corn syrup.
What the research may be missing
It is important to consider the observational design of the study. Researchers observed participants’ existing dietary habits and then examined their health over time. They did not randomly assign people to drink sugary beverages or avoid them.
As a result, the findings show an association, rather than demonstrating that sugar-sweetened beverages directly cause stomach cancer.
Notably, the researchers had limited information on participants’ Helicobacter pylori infection status, an important established
Additionally, the study population was predominantly white, which limits how confidently the findings can be generalized to other groups. Dietary information was also based on participants’ reports, which can be affected by recall and reporting errors.
More research is still necessary to determine the association between sugar-sweetened beverages and stomach cancer, and whether there is a biological mechanism that could explain the relationship.
For now, the study adds to evidence suggesting that frequent consumption may increase the risk of health conditions and reducing consumption may be beneficial for several reasons.
