Black raspberries may help prevent bowel cancer, new research suggests.
Scientists found that a freeze-dried version of the fruit could reduce the number of tumours in a strain of mice prone to the disease by 60%.
The incidence of bowel tumours was cut by 45%.
Previous research had indicated that black raspberries have antioxidant and anti-cancer properties.
In the study, the fruit inhibited tumour development by suppressing a protein called beta-catenin.
Tumour incidence and numbers were both reduced by 50% in another strain of mouse vulnerable to colitis, an inflammation of the large intestine that can contribute to bowel cancer.
"We saw the black raspberry as a natural product, very powerful, and easy to access," said study leader Dr Wancai Yang, from the University of Illinois in Chicago.
The findings were published today in the journal Cancer Prevention and Research.
Both mouse strains were either fed a Western-style, high fat diet, or the same diet supplemented with 10% freeze-dried black raspberry powder for 12 weeks.
Scientists saw a broad range of protective effects in the bowels of the mice given the supplement.