Westerners’ carb-rich diets have long been linked to high levels of cancer, and scientists have begun to work out why. In an experiment with mice, gut bacteria bridged the gap, explaining why sugar-heavy diets can cause cancer, researchers report in the July 17 Cell.
Colorectal cancer ranks third on the list of deadliest cancers, and the disease hits developed countries harder than developing ones. Nearly one of every 15 people in Western nations will suffer from the condition, and doctors suspect that carbohydrate-laden diets contribute to the problem.
In country after country where people have switched to Western-style diets heavy in refined sugars such as high fructose corn syrup, the incidence of colorectal cancer has increased, says geneticist Scott Bultman of the University of North Carolina, Chapel Hill, who was not involved in the study. Until now, the underlying connection between food and colon cancer has been cloudy. “This study gives a good mechanism for how diet is tied to colon cancer,” Bultman says.