Previous research has offered possible reasons for an association between glucose metabolism and cancer risk. Prof Khaw says that both diabetes and bowel cancer may share common predisposing factors. It is already accepted that a high fibre diet and regular exercise can help protect against both diseases.

Alternatively, hormonal changes associated with diabetes could promote tumour risk.

"Instead of looking at insulin we measured glycated haemoglobin “ a marker of blood glucose levels over the past few months “ which is likely to be a good indicator of metabolic processes that influence insulin levels," she says.

"Understanding these metabolic changes, and the lifestyle factors responsible, may help us to prevent and treat cancer."

Prof Robert Souhami, Director of Clinical and External Affairs, says: "Colorectal cancer is one of most common cancers and is the second most common cause of cancer death. This puts it at the top of the research agenda and any information that helps formulate prevention strategies is welcome."

*(1) Cancer Epidemiology and Biomarkers: Vol 13; No. 6*(2) glycated haemoglobin*(3)The EPIC study began in 1992 and is looking prospectively at the diets of 400,000 men and women aged 45 “ 74 years in nine European countries. Extensive social, medical and lifestyle information is being collected as well as biological samples.

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