What happens when rural Africans eat a Western diet for two weeks

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We all know that a diet that is too rich in processed foods is not good for the health, but a 2015 study highlighted exactly the extent to which fast food can trigger extremely harmful biological changes. 

“let food be thy medicine and medicine be thy food”. As part of the study published in Nature Communications, the researchers asked 20 Americans who routinely ate fast food to swap their diets with 20 people living in the middle of the countryside in South Africa. They immediately noticed “remarkable” changes in the biomarkers for colon cancer in the South African participants. However, the good news was that the Americans considerably reduced these biomarkers, thanks to their new rural diet -including the presence of mucous and bile in their colons.

“In just two weeks, a change in diet from a Westernised composition to a traditional African high-fibre, low-fat diet reduced these biomarkers of cancer risk, indicating that it is likely never too late to modify the risk of colon cancer”, explained Stephen O’Keeffe of the University of Pittsburgh in the United States, the main author of the study. The researchers got the idea for this study after having noticed that African Americans present with bowel cancer rates that are 13 times higher than those of rural South Africans.

They already knew that this difference was likely to be due to the fact that Americans eat lots of animal proteins and fats, to the detriment of fibre. But they were not sure of how quickly a dietary change could have an impact on the risk of colon cancer.

“The food changes resulted in remarkable reciprocal changes in mucosal biomarkers of cancer risk and in aspects of the microbiota and metabolome known to affect cancer risk”, noted the researchers. Although the sample size in their study is very small, the study contributes to a vast body of existing research, which links poor diet to debilitating disease. The researchers believe that up to one third of cases of colon cancer could be avoided with dietary changes. A previous study also showed that only five days of eating a high fat diet could change the way our bodies process food.