Which of the following is NOT a risk factor for colorectal cancer?

A high fiber diet is recognized for its protective effects against colorectal cancer, rather than being a risk factor. Numerous studies suggest that diets rich in fiber, particularly from fruits, vegetables, and whole grains, can contribute to a lower risk of developing colorectal cancer. Fiber may help in various ways, including promoting regular bowel movements, improving gut health, and potentially lowering the levels of certain harmful substances in the colon.

In contrast, increasing age is a well-established risk factor for colorectal cancer, with the incidence rising significantly after the age of 50. Inflammatory bowel disease, such as Crohn's disease and ulcerative colitis, is also associated with an increased risk due to chronic inflammation of the intestinal lining. Additionally, a family history of colon cancer can indicate a genetic predisposition to the disease, thus making it a significant risk factor for those individuals.

Therefore, the assertion that a high fiber diet is not a risk factor holds true, as it is actually linked with a decrease in risk for colorectal cancer.