My physician had told me the number one way to reduce the risk of colon cancer was a few cups of coffee a day; he was actually disappointed when I had given it up.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4874555/
I had a colonoscopy when I turned 50 and the doctor was laughing about it to me afterwards. He said it looked like I ate scouring powder because my colon was cleaner than any he had ever seen. Lots of fiber I guess.