Low-insulin-response diets may decrease plasma C-reactive protein by influencing adipocyte function

Abstract

Hepatic production of many acute phase reactants, including C-reactive protein (CRP), is induced primarily by interleukin-6 (IL-6). A significant fraction of the plasma pool of IL-6 derives from adipocytes. Physiological concentrations of insulin as well as of catecholamines have been shown to boost adipocyte production of IL-6 dose-dependently. High fasting and postprandial insulin levels can increase adipocyte exposure to catcholamines by activating the sympathetic nervous system, as well as by provoking postabsorptive hypoglycemia that triggers adrenal secretion of epinephrine. It follows that diets which promote low diurnal insulin levels – by minimizing the stimulus to postprandial insulin release, and by aiding muscle insulin sensitivity – should be associated with lower CRP levels. In fact, recent epidemiology demonstrates a correlation between dietary glycemic load and serum CRP in women, and a recent clinical study reports a 28% reduction in serum CRP following adoption of a whole-food vegan diet rich in soluble fiber. Whether very-low-fat diets which promote insulin sensitivity – and thus down-regulate insulin secretion – can influence CRP, remains to be seen. These considerations suggest that it may be possible to achieve worthwhile reductions in CRP by avoiding high-insulin-response starchy foods and by ingesting more soluble fiber, in foods or as a meal-time supplement.