High carb intake not linked to risk of colorectal cancer
NEW YORK (Reuters Health) - A high carbohydrate intake, a high glycemic index, and a high glycemic load do not appear to increase the risk of colorectal cancer in women, according to study findings published in the February issue of the American Journal of Epidemiology.
"Ample evidence indicates that insulin resistance and associated complications, such as elevated fasting glucose (and) insulin ... are implicated in colorectal carcinogenesis," Dr. Susanna C. Larsson, of the Karolinska Institute, Stockholm, Sweden, and colleagues write. They note that diets with a high glycemic load might increase the risk of colorectal cancer "owing to their potential to increase postprandial glucose and insulin levels."
The researchers prospectively examined the associations between carbohydrate intake, glycemic index, and glycemic load and the risk of colorectal cancer among 61,433 women enrolled in the Swedish Mammography Cohort, which was established between 1987 and 1990.
The women completed a 67-item food frequency questionnaire at baseline and a 96-item follow-up questionnaire in 1997. Computerized record linkage of the study population to the national and regional Swedish Cancer registers was used to ascertain incident cases of colorectal cancer.
The women were followed for a mean of 15.7 years. During that time, a total of 870 incident cases of colorectal adenocarcinoma were diagnosed. No associations were observed between carbohydrate intake, glycemic index, and glycemic load and the risk of colorectal cancer, colon cancer, or rectal cancer.
"Future studies should examine the insulin index of foods in relation to cancer risk," Larsson's team suggests.
Am J Epidemiol 2007;165:256-261.