Add Coke and Pepsi to the ever-expanding list of foods and drinks that could possibly increase the risk of cancer. A 14-year study of 60,500 Singaporeans found that those who drank two or more soft drinks per week had nearly double the risk of developing pancreatic cancer, a study published in Cancer Epidemiology, Biomarkers & Prevention reveals. Those who drink sugar-sweetened carbonated drinks were 87% likelier to develop pancreatic cancer than those who don't.The pancreas produces hormones including insulin, which controls levels of blood sugar, and enzymes that help digest food. The researchers believe soft drinks' high sugar content may increase insulin levels -- which may be linked to the growth of pancreatic cancer cells. Pancreatic cancer, although rare, is one of the deadliest forms of cancer: Only 5% of those diagnosed live more than five years, according to the American Cancer Society. Patrick Swayze died from the disease in September, and it has also afflicted Apple (AAPL) CEO Steve Jobs.

Some critics argue that it's hard to isolate the cause of increased cancer risk. Those who drink sweetened carbonated beverages may also smoke or have poor nutrition, both factors that could affect cancer risk. Still, studies like these have fueled initiatives to remove junk food from schools. The Obama administration intends to "begin a drive this week to expel Pepsi, French fries and Snickers bars from the nation's schools in hopes of reducing the number of children who get fat during their school years," The New York Times reports.

Scientists believe the overall risk is small, even to soft drink fans, but 24/7Wallst points out that the study could add to Coca-Cola's (KO) and PepsiCo's (PEP) challenges amidst recent public drives toward healthier eating habits. Indeed, both companies have expanded their product lines to offer healthier products. The study also examined fruit juice but found no link between drinking juice and developing pancreatic cancer.