That morning bagel, bowl of corn flakes, or packet of instant oatmeal could be increasing your risk of lung cancer, according to a study published this month. NBC News reports researchers in Texas found a link between foods with a high glycemic index and lung cancer, which kills more Americans per year than any other cancer. After comparing the diets of more than 1,900 people with lung cancer and more than 2,400 without it, researchers found a 49% increase in lung cancer risk for those who ate the most high glycemic foods versus those who ate the least, according to the Telegraph. Forbes reports the glycemic index measures how quickly carbs raise blood sugar levels. Foods with a high glycemic index include white bread, many breakfast cereals, white rice, pineapple, melons, popcorn, and more.
High glycemic foods have been linked to other cancers in the past, but doctors aren't sure why they would contribute to lung cancer. One possibility is that as foods with a high glycemic index increase insulin levels, they also increase insulin-like growth factors. Those IGFs could play a role in growing small tumors. Another interesting result from the study: nonsmokers who ate a lot of high glycemic foods were more than twice as likely to have lung cancer than nonsmokers who ate the least amount of those foods. While the study isn't conclusive, the doctor who led it says eating foods with a low glycemic index may lower the risk of lung cancer. Those foods include stone-ground whole wheat bread, rolled oatmeal, non-starchy vegetables, and most fruits. (These five states have the most cancer deaths.)