Other known epidemiological risk factors are family history, inflammatory bowel disease, smoking and type-2 diabetes. But out of all the risk factors that elevate colon cancer risk, diet is the one environmental and lifestyle factor that may be the easiest to control ---simply by changing people's behavior and eating habits----if we knew the exact connections. "There's epidemiological evidence for a strong link between obesity and increased tumor risk," said School of Life Sciences assistant professor Miyeko Mana. Mana added, "And in the intestine, the stem cells are the likely cell of origin for cancer. So, what is that connection? Well, diet is something that feeds into that cycle of obesity and colorectal cancer."