Sam P.K Collins in ThinkProgress:
...In a study conducted at the University of Pittsburgh, 20 African Americans and 20 South Africans switched diets for two weeks. In this time, the Africans consumed traditional American food — meat and cheese high in fat content — while African Americans took on a traditional African diet — high in fiber and low in fat, with plenty of vegetables, beans, and cornmeal, with little meat.
Boiled Plantain with Vegetable egg (Egusi) stew image via Dobby
After the exchange, researchers performed colonoscopies on both groups and found that those in the African diet group increased the production of butyrate, a fatty acid proven to protect against colon cancer. Members of the American diet group, on the other hand, developed changes in their gut that scientists say precede the development of cancerous cells...[more]