|That the type of diet a person eats affects their colon cancer risk is not only self-evident, but also commonly known.
A joint US-British study that was published in "Nature Communications" has now demonstrated how strong this effect is and how quickly it has an impact. The researchers found significant effects within just two weeks following dietary change.
Scientists from Imperial College London and the University of Pittsburgh (Pennsylvania) included 20 African Americans and 20 people from rural South Africa in their study. The groups swapped diets under tightly controlled conditions: the Africans ate a Western diet with high amounts of protein and fat, while the Americans consumed lots of fibre and low amounts of fat and proteins.
Before and after the trial, the researchers examined the subjects' colons using colonoscopy, analysed bacteria samples and determined the colon cancer risk using several biomarkers. At the start, about half of the Americans had polyps - which can progress to cancer - but none of the Africans.
Following the diet swap, the American group demonstrated a significant drop in inflammation levels and a decrease in biomarkers for cancer risk. However, in the African group the factors indicating cancer risk had increased dramatically.
|Of course, this study alone does not suffice to definitively say whether or not dietary change would have led to more or fewer cases of cancer in the respective groups. But the findings show that a change in diet impacts the cancer risk within just a short time, and that it is therefore never too late to change one's diet, said the authors. In any case, the scientists raised serious concerns regarding the increasing westernisation of diets in African countries.