Green bananas, cold boiled potatoes and other sources of virtually indigestible starch, "nutritionist in Cambridge say, may provide particularly strong protection against bowel cancer." On the Whole, a diet rich in starch, not just fiber. may be a "major protective factor."
In an analysis of diet and cancer rates from 12 countries, a strong association between starch consumption and cancer of the large bowel, colon and rectum has been founded. on average, the more starch consumed in a population, the lower the incidence of these diseases.
Writing in the BRITISH JOURNAL OF CANCER, Sheila Bingham and her colleauges argue that the anti-cancer effect comes from starch that escaped digestion in the small intestines.
As this "resistant" starch moves into the colon. bacteria break it down by the process of fermentation. This process produces short-chain fatty acids, particularly butyrate, which has proved to be a powerful suppresos of the growth of cancer cells.
Bacteria which feed on the starch also help prevent colon cancer by increasing stool weight, thereby diluting the contents of the colon and speed the passage of potentially cancer-causing waste products.
Nutritionists typically lump starches with sugars under the heading "carbohydrates."
Bananas that are still green at the tips contain substantial amounts of resistant starch, whereas in ripe bananas with black spots most of the starch has been converted to sugars.
