Study: Soda drinkers at increased risk of pancreatic cancer

By Larue Huget/Rob Stein - February 8, 2010 - Washingtonpost

A study published today in the journal Cancer Epidemiology, Biomarkers & Prevention finds that people who drink two caloric soft drinks a week have nearly double the risk of developing pancreatic cancer when compared to those who drink less.

The research tracked 60,524 men and women in the Singapore Chinese Health Study for 14 years and found that the soft-drinkers increased their risk of contracting the deadly cancer by 87 percent. The relationship held up even when smoking and a handful of other habits were taken into account. The study did not look at consumption of diet soda; soft drinks were defined as "sugar-sweetened carbonated beverages."

The study, funded by the National Cancer Institute, notes that lifestyles in Singapore have much in common with those in the U.S. and that the findings should apply to Caucasians as well as to the Asians who were tracked.

Lead author Mark Pereira, an associate professor in the School of Public Health at the University of Minnesota, suggests that the high level of sugar in sodas may boost insulin levels in the body, which in turn might spur the development of pancreatic cancer cells.

But no such connection was found between drinking fruit juices, whose sugar content often matches that of soft drinks.

The findings, while provocative and frightening, could use some perspective. First, the total number of pancreatic cancer cases found over the 14 years of the study was just 140. Of those, 18 occurred among people who'd reported consuming two or more sodas per week, and 12 among those who drank less than two; 110 occurred in people who'd reported drinking no soda.

The study acknowledges that those small numbers might make the association a little more tenuous, "limiting the power" of the data and "giving potential to a chance association." It also cites four earlier studies that examined the soda-pancreatic cancer link that came to varying conclusions, including finding no link at all to finding an association for women but not for men.

Speaking on behalf of the American Beverage Association, consultant Richard H. Adamson said, "The study is, in my opinion, a weak study." Adamson, former vice president for science and technical affairs for the beverage association and, before that, a researcher at the National Cancer Institute, says that the study was "very small with regard to number of cases" of pancreatic cancer for major conclusions to be drawn from its data.

Further, Adamson says, the researchers didn't correct for other known pancreatic-cancer risk factors such as chronic pancreatitis, high-fat diet, workplace exposure to chemicals or gender (males are much more likely to get this cancer than females). The fact that the association didn't hold for juice raises questions, he said, as the sucrose in Singapore soft drinks "breaks down into the same thing that's in juice."

In the end, Adamson said, "The study doesn't scare me. I continue to drink soft drinks."

I'm not a soda drinker, and this study doesn't inspire me to start sipping. But while many public-health advocates believe we'd all be better off without soda in our lives, I'm not sure that if I did enjoy soda I'd stop drinking on the basis of this study alone. Because pancreatic cancer is relatively rare, even doubling your risk leaves your individual risk pretty low.

On the other hand, given the grim prospects for surviving pancreatic cancer (fewer than 5 percent of those diagnosed are alive after five years), and that fact that there's no screening test and very few treatment options, anything we can do to reduce our risk might be worth considering.

How about you? Are you a soda drinker? Does this study make you inclined to cut back?