EFFICACY OF PSYLLIUM IN REDUCING SERUM-CHOLESTEROL LEVELS IN HYPERCHOLESTEROLEMIC PATIENTS ON HIGH-FAT OR LOW-FAT DIETS

Objectives: To determine the efficacy of psyllium in reducing serum ch olesterol levels in patients on high- or low-fat diets. Design: Double -blind, placebo-controlled, 16-week parallel trial. The study included an 8-week baseline period and an 8-week treatment period. Patients: H ealthy men and women, 21 to 70 years old, with primary hypercholestero lemia (total serum cholesterol greater-than-or-equal-to 5.7 mmol/L [22 0 mg/dL]). Thirty-seven participants followed a high-fat diet and 81 p articipants followed a low-fat diet. Intervention: Participants were r andomly assigned to either psyllium, 5.1 g twice a day, or placebo. Me asurements: Fasting lipid and apolipoprotein concentrations, including direct low-density lipoprotein (LDL) cholesterol quantification; nutr itional analyses of 4 days of 7-day food records to monitor dietary co mpliance; and physical examinations, clinical chemistry and hematologi c studies, and urinalysis to assess treatment safety. Main Results: Ps yllium recipients in both the high- and low-fat diet groups showed sma ll but significant decreases (P < 0.05) in total cholesterol and low-d ensity lipoprotein (LDL) cholesterol levels. Total cholesterol and LDL cholesterol levels decreased 5.8% and 7.2%, respectively, in psyllium recipients on high-fat diets and 4.2% and 6.4%, respectively, in psyl lium recipients on low-fat diets. No significant difference was seen i n LDL cholesterol response when psyllium recipients on low- and high-f at diets were compared (P > 0.2). No significant reductions in lipid-l evels were observed in placebo recipients. Based on the National Chole sterol Education Program LDL cholesterol classification system, 39% of the psyllium recipients improved in LDL cholesterol classification (P < 0.0001) compared with 20.3% of placebo recipients (P > 0.2). Conclu sions: Psyllium produces a modest but significant improvement in total cholesterol and LDL cholesterol levels in persons on either low-fat o r high-fat diets. Psyllium, when added to a prescribed low-fat diet, m ay obviate the need for typical lipid-lowering medications or may prov e to be a valuable adjunct to other treatments in patients with modera tely elevated LDL cholesterol levels.