People who drink two or more soft drinks - and especially carbonated colas - every week double their risk of developing pancreatic cancer. The drinks - defined by researchers as carbonated and sugar-sweetened - increase levels of insulin, which is a known cause of the cancer. The effect was not seen in people who drank fruit juice. Researchers from the University of Minnesota made the discovery after they tracked the health profiles of 60,524 men and women in Singapore for 14 years. In that time, 140 people developed the cancer, and after eliminating all other options, the researchers discovered they drank at least two carbonated drinks a week. On average, they were drinking five drinks a week. Although the cancer is rare, it is usually fatal, say researchers. (Source: Cancer Epidemiology, Biomarkers & Prevention, 2010; 19: 447-55).