Tel Aviv University researchers have found a connection between obesity in childhood and colon or bladder cancer in adulthood. The risk for these malignant tumors is 40 percent higher in adults who were overweight as children.Dr. Adi Leiba, Prof. Arnon Afek and Dr. Ari Shamiss of Tel Aviv University’s Sackler Faculty of Medicine and Sheba Medical Center in Tel Hashomer, together with researchers from the IDF’s medical corps and the Hadassah Medical Organization, just published their study in the journal Cancer Epidemiology, Biomarkers & Prevention. It has long been known that maintaining normal weight is vital because being overweight can raise the risk of diabetes, heart disease and joint and muscle pain. But the research team, who studied the health records of 1.1 million 18-yearold male draftees and followed them up for a period of another 18 years, has now found that obesity can be clearly linked with the two kinds of cancer.The researchers began with urological cancer and cancer of the large intestine, but state that in the future, they think more research will show direct links between childhood obesity and many others tumors – including pancreatic cancer, which they are now studying.They defined obesity in children as weight in the top 15% of the body mass index (BMI) tables. The American Heart Association has said that one out of every three children and teenagers in the US is obese.The rate is still lower in Israel, but the numbers are rising.Shamiss said the results of the study demonstrated that more research is needed in the field.“For example, we must examine whether obesity is a direct risk factor for cancer or perhaps the two phenomena result from a joint genetic variation. Basic research can help us understand in more depth the connection between obesity and cancer,” he said.One of the critical questions, he added, was whether weight loss reduces children’s risk of contracting cancer as an adult.The database included fat children who were compared to those of normal weight, but did not investigate whether weight loss had a significant difference in risk.“Today, we see the importance of preventing obesity in children, but this new finding undoubtedly produces a warning light,” Shamiss concluded.