What happened when scientists put African-Americans on a diet from the long-ago "motherland" and African-Africans on an American diet? Nothing good for the Africans.

20 African-Americans and 20 South Africans switched diets for two weeks. The African-Africans consumed traditional American food, meat and cheese high in fat content, while African-Americans took on a traditional African diet, which was high in fiber and low in fat, with vegetables, beans, and cornmeal but little meat. 

Then the University of Pittsburgh 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 developed changes in their gut that scientists say precede the development of cancerous cells, notes ThinkProgress.