A University of Minnesota study shows that consuming a lot of soft drinks appears to increase a person's risk of pancreatic cancer.
The findings are based on the dietary habits of more than 60,000 people in Singapore who were observed for 14 years.
The study found a nearly two-fold increase in the risk of pancreatic cancer among people who consumed at least two carbonated, sugar-sweetened beverages per week, compared to those who did not consume soft drinks.
The pancreas is the organ which produces insulin, the substance that helps the body metabolize sugar. U of M researcher Mark Pereira said people who drink soda release a jolt of insulin into their pancreas, which may overwhelm the organ.
"They're pretty much all sugar, stimulate a lot of blood glucose, blood sugar and then insulin," Pereira said. "And as we know, the consumption of soft drinks in our society is very common and the portion sizes are unfortunately very large; so lots of sugar, lots of insulin."
People who drank mostly fruit juice instead of sodas did not have the same risk, according to the study.
Pereira and colleagues said they followed 60,524 men and women in the Singapore Chinese Health Study for 14 years.
Over that time, 140 of the volunteers developed pancreatic cancer. Those who drank two or more soft drinks a week had an 87 percent higher risk of being among those who got pancreatic cancer.
Pereira said he believed the findings would apply elsewhere.
"Singapore is a wealthy country with excellent health care. Favorite pastimes are eating and shopping, so the findings should apply to other western countries," he said.
Pereira said his researchers were able to account for many contributing factors such as diabetes, age and whether or not a person smoked.
"The results held up, actually, to all that rigorous analyses," he said. "So it suggests that there might be something going on here which could be cause and effect, but we can't say from observational studies."
There are several limitations to the study however. People who self-report on their diet often don't remember it accurately, and it's difficult to sort out the effects of other dietary behaviors.