Which factor does NOT increase the risk of colorectal cancer?

A diet high in fiber is known to be protective against colorectal cancer rather than a risk factor. This is due to the beneficial effects of dietary fiber, which promotes healthy bowel movements, helps regulate gut bacteria, and may reduce gut inflammation. Research indicates that a higher intake of fiber-rich foods, such as fruits, vegetables, and whole grains, can lower the risk of developing colorectal cancer.

In contrast, age, the presence of adenomatous polyps, and genetic predisposition are well-established risk factors for colorectal cancer.

As individuals age, the likelihood of developing various cancers, including colorectal cancer, increases. Adenomatous polyps are precursors to colorectal cancer; their presence indicates an increased risk because they can mutate over time into malignant tumors. Genetic predisposition, often due to inherited conditions like familial adenomatous polyposis or Lynch syndrome, also significantly raises the risk of developing colorectal cancer due to inherited mutations that affect tumor suppression mechanisms.

Thus, a high-fiber diet promotes prevention, while the other factors mentioned correspond with an increased risk of colorectal cancer.