New study links high blood sugar to colorectal cancer

A research team led by ACSH advisor Dr. Geoffrey Kabat, of the Albert Einstein College of Medicine in the Bronx, has found that high blood sugar in post-menopausal women is associated with a roughly two-fold increased risk of colorectal cancer.

While diabetes has already been linked with colorectal cancer, it hasn t been established whether that association is the result of circulating insulin or glucose. In order to investigate this question, Kabat and colleagues analyzed data from nearly 5,000 women participating in the Women s Health Initiative. The researchers looked at baseline and serial follow-up measurements of fasting blood glucose and insulin over a median of 12 years, as well as taking into consideration variables of age, body mass index (BMI), alcohol consumption, physical activity, ethnicity, and family history of colorectal cancer. When compared with postmenopausal women whose glucose levels were in the lowest third of the participants, those with levels in the highest third had a 74 percent greater risk of developing colorectal cancer. And the increased risk for colon cancer, specifically, was even higher more than double.

As the authors point out in The British Journal of Cancer, where the results of the study were published online, their analysis was limited by the small number of colorectal cases (81 in total). And while ACSH s Dr. Ruth Kava is impressed with the significantly increased risk the researchers found, ACSH s Dr. Gilbert Ross Ross would like to know more about the mechanism of this relationship between colorectal cancer and elevated blood sugar levels. Scientists have speculated that glucose could contribute to the development of this kind of cancer by providing an energy source for malignant cells, but a definitive cause-and-effect relationship between high blood sugar levels and colorectal cancer has yet to be established.