Can the risk of colon cancer be lessened?

Colon cancer was rare or uncommon in the past, and still is in traditionally-living third world populations. It now affects 3-5% of western populations. Epidemiological, case control, experimental and other studies suggest that proneness to colon cancer can be lessened by major dietary changes, principally decreasing fat intake by a third, and doubling the intake of fiber-containing foods, especially vegetables and fruit--recommendations similarly advocated for the avoidance of coronary heart disease and other degenerative diseases. Among nondietary factors, evidence indicates familiality, obesity and atmospheric pollution to be contributory, while parity, physical activity, solar radiation, high social class, estrogen use, and aspirin use, appear protective. Despite insufficiencies of knowledge of prevention, avoiding action should certainly be taken by those familially prone. For the rest, conceivably a prudent life-style could benefit a proportion avoiding colon cancer.