Boston - February 2003, Harvard Medical School affiliate Brigham and Women's Hospital - A diet with a high dietary glycemic load may increase the risk of colorectal cancer in women, according to a new study. Glycemic load is a measure of how quickly a food's carbohydrates are turned into sugars by the body (glycemic index) in relation to the amount of carbohydrates per serving of that food. Some examples of foods with a high glycemic load are white breads, white rice, and some pastas.
The growing recognition that colorectal cancer may be promoted by hyperinsulinemia and insulin resistance suggests that a diet inducing high blood glucose levels and an elevated insulin response may contribute to a metabolic environment conducive to tumor growth. Simin Liu, M.D., Sc.D., of Harvard Medical School and Brigham and Women's Hospital, and colleagues looked at information gathered from the Women's Health Study. They looked at the association between dietary glycemic load, overall dietary glycemic index, carbohydrate, fiber, nonfiber carbohydrate, sucrose, and fructose with the subsequent development of colorectal cancer.
Dietary glycemic load was associated with an increased risk of colorectal cancer. Total carbohydrate, nonfiber carbohydrate, and fructose were also associated with increased risk. "A diet with a high glycemic load may increase the risk of colorectal cancer by affecting insulin and insulin-like growth factors or...by exacerbating proinflammatory responses, either locally or systemically," the authors write. "Further work is needed to elucidate these mechanisms."