In America the risk of developing colorectal cancers begins to rise after the age of 50. An exception to that rule is in African Americans whose risk begins to rise at an earlier age. But colon cancers in native Africans are relatively rare - some studies put it at 50 times less likely than Americans.
That statistic alone causes researchers to focus on environmental factors. Dietary recommendations in America tout protective factors such as fiber, calcium, and vitamins A, C, and folic acid; but less emphasis is placed on removing risks such as restricting the intake of red meats.
Researchers compared rural and urban black South African diets to that of Caucasian South Africans, Caucasian Americans, and African Americans. The study showed that black South Africans, both rural and urban, still eat a largely carbohydrate dense diet, low in meat, consisting of a highly refined corn meal (maize) that is low in fiber. This maize product was found to be resistant to absorption in the small intestine and thus while low in fiber may have a similar action as it enters the colon. Overall, researchers believe that the lack of fat and animal protein in the diet was the main deterrent to the development of colorectal cancers in the African study group.
Of course further study is needed to determine that pathway of the diet to cancer link. There was strong evidence found during these studies that the two types of diets allow for very different bacterias found in the gut of the two different population groups. This relationship between diet and the types and quantities of bacteria could be the key to explaining the differences in colon cancer rates on two continents.
The most important thing to do to prevent colon cancer is get screened! If you are African American you could be at greater risk. It is important to know your family history and to talk with your gastroenterologist at GI Associates about the proper time to begin your screening. today.