I'm weighing in a month late on this but it has been a month very relevant to this discussion. About a month ago my doctor found a polyp in my colon that he said has probably been growing for two years. I eat very healthy (nearly McDougall), two to three cups of fruits and three to four cups of vegetables every day, about 50 grams of fiber a day. I'm normal weight, and I exercise every day for 40-50 minutes. I'm also only 46. So I have been wondering about this--just an anomaly to have the polyp, or genetics (my dad had them too), or something else?
The key, I am wondering, might be in the fact that it's been growing for two years. I did make a big change about two years ago, because I was starting menopause--I began to have a shake every day with isolated soy protein powder. So many people tell you soy is the miracle for menopause if you don't want to do HRT. "Revival soy" and other products are all over the menopause self-help boards. But after I got the diagnosis of the large polyp I began to do research and found what Dr. McDougall says about soy and particularly isolated soy protein. Now I wonder if I may have caused my system harm from (1) too much protein in general; and (2) the isolated soy protein. There is a genetic factor at play--my dad had polyps early, about my age also. But he had a much different diet back then--very standard Western.
I have discarded the soy protein, of course--and I'm ready to endure hot flashes or whatever comes without it! I thank God I keep up on Dr. McDougall's advice and looked for what he says about soy, as I often do about other health issues.
(Colonoscopy is in two days--just finished my "last meal" and feeling sorry for myself

but also overall very lucky for this discovery)