A 20-year study has found that the starch in bananas can reduce the risk of some types of cancer by more than 60%.
The study, led by experts at the Universities of Newcastle and Leeds and published in the journal Cancer Prevention Research , could be important in reducing upper bowel cancer.
During the study, participants received a dose of this starch - known as resistant starch - equivalent to what you would get from eating a banana that is not overripe and still slightly green.
About 1,000 patients with Lynch syndrome - an inherited disorder that increases the risk of cancer, particularly in the colon and rectum - took the dose for an average of two years. The study found that while starch did not affect colon cancer, it reduced the incidence of cancer in other parts of the body by more than half.
The treatment had a particular effect on cancers of the upper gastrointestinal (GI) tract, including cancers of the esophagus, stomach, biliary tract, pancreas and duodenum.
The dose taken is equal to that of eating a banana every day, but they should not be too ripe and not soft; so the bananas should be slightly green.
This starch can be taken as a supplement in powder form and is found naturally in peas, beans, oats and other starchy foods.
