Effects of dietary inulin on serum lipids in men and women with hypercholesterolemia

Inulin, a carbohydrate derived from plant sources, can be classified as a soluble fiber. Since inulin has a bland flavor and a fat-like texture, it can be incorporated into various food preparations to replace sugar and fat. Soluble fibers have been shown to modulate serum lipids, therefore, the present study examined the effect of consuming three servings per day of inulin-containing foods, compared to similar foods without inulin, on serum lipid profiles among hypercholesterolemic men and women. In addition, the practicality of including 18 g/day of inulin in a low-fat diet was investigated. The study was a randomized, double-blind, crossover trial with two six-week treatment periods, separated by a six-week washout. Twenty-one men and women with baseline low density lipoprotein cholesterol (LDL-C) 3.36-5.17 mmol/L completed the trial. Within each treatment sequence, total and LDL-C increased significantly (7.4% and 12.3%, respectively) during the control phase. There were small, non-significant declines in total-(1.3%) and LDL-C (2.1%) during the inulin phase. Thus, differences in response between periods (inulin minus control) were statistically significant (P < 0.05) for LDL-C (-14.4%) and total cholesterol(-8.7%), respectively. Mild gastrointestinal discomfort was more common during the inulin than control food phase, however, the gastrointestinal side effect profile of inulin was similar to that of other soluble fibers. Although it is not possible to draw firm conclusions from these data, inulin may have blunted the hypercholesterolemic effects observed during consumption of control foods. Additional research will be required to confirm the possible lipid-modulating properties of dietary inulin in humans. (C) 1998 Elsevier Science Inc.