Excessive blood sugar levels are linked to an increased risk of colorectal cancer, according to a study led by researchers at Albert Einstein College of Medicine of Yeshiva University. The findings appear in a recent online edition of the British Journal of Cancer.
The study involved nearly 5000 postmenopausal women participating in the National Institutes of Health’s landmark Women’s Health Initiative study. Fasting blood sugar and insulin levels for these women were assessed at baseline and several more times during the following 12 years.
Colorectal cancer had developed in 81 of the women by the end of the 12-year period. Results showed that high baseline glucose levels were related to an increased colorectal cancer risk. Furthermore, women in the highest third of baseline glucose levels were nearly twice as likely to develop colorectal cancer compared to women in the lowest third of blood glucose levels. When researchers studied repeated glucose measurements over time, results were similar. However, no relationship was detected between insulin levels and the risk for colorectal cancer.
Obesity is a known risk factor for colorectal cancer and is usually accompanied by high blood levels of insulin and glucose. Although scientists have suspected that the effect of obesity on colorectal cancer risk comes from the high insulin levels it causes, the Einstein study suggests that the influence of obesity on this cancer may be a result of elevated glucose levels.
“The next challenge is to find the mechanism by which chronically elevated blood glucose levels may lead to colorectal cancer,” said Geoffrey Kabat, PhD, a senior epidemiologist at Einstein and lead author of the paper. “It’s possible that elevated glucose levels are linked to increased blood levels of growth factors and inflammatory factors that spur the growth of intestinal polyps, some of which later develop into cancer.”
Source: Albert Einstein College of Medicine of Yeshiva University