Insulin resistance is the loss of sensitivity of the receptors on each cell that respond to insulin from to repeated over-stimulation by insulin due to high blood sugar levels. High levels of insulin “in the background” do many kinds of damage in the run-up to type 2 diabetes when the body’s capacity to produce ever higher compensatory levels of insulin finally fails and the blood sugar goes up. My patients will certainly recognize that insulin is, of course, a hormone—and that excessive levels are a tumor promoter (along with the related insulin-like growth factor (IFG1). This paper recently published in the journal Cancer Science looks at the epidemiological link between insulin resistance and cancer.

“Epidemiological evidence from our prospective study, the Japan Public Health Center-based Prospective (JPHC) study, and systematic literature reviews generally support the idea that factors related to diabetes or insulin resistance are associated with an increased risk of colon (mostly in men), liver, and pancreatic cancers… The suggested mechanism of these effects is that insulin resistance and the resulting chronic hyperinsulinemia and increase in bioavailable insulin-like growth factor 1 (IGF1) stimulate tumor growth.”

The data from the Japan Public Health Center-based Prospective (JPHC) study support this conclusion:

“…there is substantial evidence to show that cancers of the colon, liver, and pancreas are associated with insulin resistance, and that these cancers can be prevented by increasing physical activity, and possibly coffee consumption.”

That’s right, coffee consumption—see the numerous posts documenting the benefits of coffee. Past and forthcoming posts report on studies that describe the association of insulin resistance and other cancers. The ‘take home’ message is that it’s important to maintain insulin at a healthy level long before the onset of type 2 diabetes by lifestyle factors (good eating and exercise) and evidence-based supplementation appropriate to your genetic and circumstantial needs.