Colon cancer, the second leading cause of cancer death in the US, aﬀects a greater proportion of African Americans than rural Africans, indicating that diet plays an important role in disease prevention. To see how traditional diets aﬀect risk factors for colon cancer, researchers assigned 20 middle aged African Americans to a traditional, African heritage diet (averaging 55g ﬁber daily and 16% calories from fat, with foods like mangos, bean soup, and ﬁsh) and 20 middle aged rural South Africans to a typical American diet (averaging 12g ﬁber daily and 52% calories from fat, with foods like pancakes, burgers, fries, and meatloaf). In just 2 short weeks, the African Americans reduced the inﬂammation of their colons, improved their markers for cancer (including increased levels of butyrate, an anti-cancer chemical), and increased the diversity of their healthy gut bacteria. On the other hand, the rural Africans eating an American diet fared worse, producing more bile acid (a risk factor for colon cancer), while decreasing the diversity of healthy gut bacteria. These results indicate that an African heritage diet can help promote a healthy digestive tract (potentially reducing colon cancer risk), and that rapid improvements can come with a change to healthier foods.
Nature Communications. 2015 Apr 28;6:6342. (O’Keefe SJ et al.)