There’s more bad news for connoisseurs of sugary soft drinks and the companies that produce them.
A report in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, found that people who consume two or more soft drinks per week nearly double their risk of developing pancreatic cancer compared to individuals who refrain from drinking them.
Pancreatic cancer is very deadly, with only 5 percent of people who are diagnosed are alive five years later.
Mark Pereira, Ph.D., senior author on the study and associate professor in the University of Minnesota School of Public Health, said people who consume soft drinks on a regular basis, defined primarily as carbonated sugar-sweetened beverages, tend to have a poor health profile overall.
However, the effect of these drinks on pancreatic cancer may be unique.
“The high levels of sugar in soft drinks may be increasing the level of insulin in the body, which we think contributes to pancreatic cancer cell growth,” said Dr. Pereira.
There was no association made between fruit juice consumption and pancreatic cancer.
For the current study, Dr. Pereira and colleagues followed 60,524 men and women in the Singapore Chinese Health Study for 14 years. During that time, there were 140 pancreatic cancer cases. Those who consumed two or more soft drinks per week and averaging five per week, had an 87 percent increased risk compared with individuals who did not.
Dr. Pereira said the results from Singapore are likely to be applicable to Americans.
“Singapore is a wealthy country with excellent health care," he said. "Favorite pastimes are eating and shopping, so the findings should apply to other western countries.”
Last September, a team of prominent doctors, scientists and policy makers urged the federal government to consider a tax on sugary drinks that they say could be a powerful weapon in efforts to reduce obesity and other ill-health effects, in the same way that cigarette taxes have helped curb smoking.
The report, published in the New England Journal of Medicine, cited research on price elasticity for soft drinks that has shown that for every 10 percent rise in price, consumption declines 8 to 10 percent. The team said lowering consumption of soda and other sweetened drinks would not only lead to shrinking the waist size of many Americans but would also reduce health risks for many serious chronic diseases.
An earlier study also linked drinking soda to an increased risk of developing esophageal cancer.
Shortly after the NEJM report, the American Heart Association jumped on board by urging people to reduce their sugary food and beverage intake to lower the risk of obesity and high blood pressure and singling out soft drinks as a prime culprit.
The soft drink industry, which has been losing market share in recent months, has adamantly resisted the notion that its products are responsible for a national increase in obesity or that a tax would help curb the problem.
No congressional action has been taken on the proposed soft drink tax.
Susan Mayne, Ph.D., associate director of the Yale Cancer Center and professor of epidemiology at the Yale School of Public Health, said the Singapore study results are intriguing but have some key limitations that should be considered in any interpretation.
“Although this study found a risk, the finding was based on a relatively small number of cases and it remains unclear whether it is a causal association or not. Soft drink consumption in Singapore was associated with several other adverse health behaviors such as smoking and red meat intake, which we can't accurately control for," said Mayne, an editorial board member of Cancer Epidemiology, Biomarkers & Prevention.
Dr. Pereira pointed out that the findings are biologically plausible. There was little statistical difference between smokers and non-smokers after taking other dietary habits into account and the results are consistent with findings in Caucasian populations.
Lynette Summerill, is an award-winning journalist who lives in Scottsdale, Arizona. In addition to writing about cancer-related issues, she writes a blog, Nonsmoking Nation, which follows global tobacco news and events.