Effect of inulin consumption on lipid and glucose metabolism in healthy men with moderately elevated cholesterol

Oligosaccharides are carbohydrates with an average degree of polymerization ranging from 2-20 sugar monomers. Inulin, a polyfructosan from the Jerusalem artichoke (Helanthus tuberosus) is classified as a non-digestible oligosaccharide. Since inulin resists digestion, it behaves similar to soluble dietary fibers and may possess some of the desirable characteristics of these fibers such as decreasing blood lipids and slowing glucose absorption. The present study was a randomized, double blind, crossover study consisting of two three-week diet periods with no washout. Participants (n=9) consumed a controlled diet +/-20g inulin in low fat vanilla ice cream. Daily intake of 20g inulin for 3 weeks significantly reduced mean serum triglyceride levels by 79 mg/dl. Plasma total, LDL, and HDL cholesterol did not differ significantly between treatments. Mean blood glucose levels after a 75 g oral glucose tolerance test did not change. Mean glucagon levels at 1 hour post-glucose load were significantly elevate (p=0.03) with inulin consumption (92.6 +/-5.6 vs. 105.2 +/- 9.3) . A trend toward elevated mean insulin and C-peptide levels at 1 hour post-glucose load was observed (p=0.09 and p=0.13), respectively.