Long-term blood cholesterol-lowering effects of a dietary fiber supplement

Background: The study evaluated the blood cholesterol-lowering effects of a dietary supplement of water-soluble fibers (guar gum, pectin) and mostly n on-water-soluble fibers (soy fiber, pea fiber, corn bran) in subjects with mild to moderate hypercholesterolemia (LDL cholesterol, 3.37-4.92 mmol/L). Methods After stabilization for 9 weeks on a National Cholesterol Education Program Step I Diet, subjects were randomly assigned to receive 20 g/d of the fiber supplement (n = 87) or matching placebo (n = 82) for 15 weeks and then receive the fiber supplement for 36 weeks. The efficacy analyses incl uded the 125 subjects (58 fiber; 67 placebo) who were treatment and diet co mpliant. One hundred two (52 fiber; 50 placebo) completed the 15-week compa rative phase. Of these subjects 85 (45 fiber; 40 placebo) elected to contin ue in the 36-week noncomparative extension phase. Results The mean decreases during the 15-week period for LDL cholesterol (L DL-C), total cholesterol (TC), and LDL-C/HDL-C ratio were greater (P <0.001 ) in the fiber group. The mean changes from pre-treatment values in LDL-C, TC, and LDL-C/HDL-C ratio for subjects in the fiber group were -0.51 mmol/L (-12.1%), -0.53 mmol/L (-8.5%), and -0.30 (-9.4%), respectively. The corre sponding changes in the placebo group were -0.05 mmol/L (-1.3%), -0.05 mmol /L (-0.8%), and 0.05 (1.5%), respectively. The fiber supplement had no sign ificant effects (P > 0.05) on HDL cholesterol (HDL-C), triglyceride, iron, ferritin, or vitamin A or E levels. Similar effects were seen over the subs equent 36 week noncomparative part of the study. Conclusions The fiber supplement provided significant and sustained reducti ons in LDL-C without reducing HDL-C or increasing triglycerides over the 51 -week treatment period.