I have beetroot on my sandwiches every day ( for 30 yrs ) and have never noticed any difference . How much of the stuff are you consuming ??
Even though I have family history, and get a colonoscopy done every 5 yrs, it's not a bad idea to get one at around the 50yr mark !!
What it can pick up is polyps......they might take 5, 10 or 20 yrs to develop, but it can nip them in the bud early.
Funny how we spend more money on our 4wd's , but ignore our own engines !!