Leading scientists say there is more evidence than ever before that fibre-rich foods prevent bowel cancer.
Following analysis of the most up-to-date research on the disease, experts said there is now "convincing" evidence that foods containing fibre can offer protection.
This is stronger than a 2007 conclusion that dietary fibre "probably" cuts the risk of the disease. New evidence includes research that says three servings a day of cereal fibre and wholegrains reduces the risk.
The World Cancer Research Fund (WCRF), which commissioned experts from Imperial College London to look at the data, said it recommended people eat a plant-based diet including fibre-rich foods such as fruits, vegetables, wholegrains and pulses such as beans.
Scientists also analysed new data on the risk of bowel cancer from red and processed meat, which adds weight to the view these are a "convincing" cause of the disease.
The WCRF and the American Institute for Cancer Research recommend people eat no more than the equivalent of about five or six medium portions of red meat such as beef and lamb a week. They say people should avoid processed meat.