Does Dietary Insulin Load Affect Colon Cancer Recurrence?
Posted: Friday, July 13, 2018
Patients with resected stage III colon cancer who followed diets that produced high insulin levels in the body had a higher risk of recurrence and mortality than did those with lower dietary insulin loads, according to the CALGB 89803 (Alliance) trial by Vicente Morales-Oyarvide, MD, MPH,of Dana-Farber Cancer Institute, and colleagues, published in the Journal of the National Cancer Institute. Consequently, the investigators encourage dietary management after colon cancer surgery and additional research to uncover the mechanisms behind their study findings.
A total of 1,023 patients with resected stage III colon cancer enrolled in this study of adjuvant chemotherapy. They completed semiquantitative food frequency questionnaires both 4 months after surgery and 6 months after the completion of adjuvant chemotherapy (14 months after surgery). The food insulin index was used to determine the postprandial plasma insulin elicited by the foods reported. This index and dietary intake were used to calculate dietary insulin load, which was then used to calculate a dietary insulin index.
Higher dietary insulin load and dietary insulin index had statistically significant associations with worse disease-free, recurrence-free, and overall survival. In terms of disease-free survival, those in the highest quintile of dietary insulin load had a higher hazard ratio than those in the lowest quintile (2.77 vs. 1.75). In addition, the link between worse disease-free survival and higher dietary insulin load seemed to be “strongest” among patients with obesity (hazard ratio = 3.66)
“We now have evidence that [patients with resected stage III colon cancer] may help avoid a recurrence of the disease and improve their prospects of survival by following a healthy diet,” lead study author Dr. Morales-Oyarvide said in a Dana-Farber press release.