Numerous studies have demonstrated a pronounced negative correlation between high-fiber diets and the incidence of colon cancer. For example, the colon cancer rate in Western countries is much higher than in many non-Western countries where people eat more fiber-rich foods, such as fruits and vegetables. Furthermore, in Scandinavia it has been conclusively shown that the higher the colon cancer rate in a given area, the lower the consumption in that area of cereals, which, like fruits and vegetables, are high in fiber. All of this shows that insufficient consumption of fiber causes colon cancer, and sufficient consumption of fiber prevents it. The argument's reasoning is vulnerable to criticism because the argument overlooks the possibility that ['foods containing fiber also contain other substances that, when consumed, tend to prevent colon cancer', 'the fiber in fruits and vegetables and the fiber in cereals have cancer-fighting properties to different degrees', 'the consumption of fiber in many countries is rising appreciably', 'the risk of many types of cancer is reduced by high-fiber diets']