Time- and dose-dependent effect of psyllium on serum lipids in mild-to-moderate hypercholesterolemia: a meta-analysis of controlled clinical trials

Abstract

Objectives: Evidences from randomized clinical trials and meta-analysis have claimed an association between the use of soluble dietary fiber from psyllium and a cholesterol-lowering effect. However, there is still uncertainty as to the dose-response relationship and its long-term lipid-lowering efficacy. This meta-analysis was primarily conducted to address the dose-response relationship between psyllium and serum cholesterol level and time-dependent effect of psyllium in mild-to-moderate hypercholesterolemic subjects. Methods: Twenty-one studies, which enrolled a total of 1030 and 687 subjects receiving psyllium or placebo, respectively, were included in the meta-analysis. The studies were randomized placebo-controlled trials, double blinded or open label, on subjects with mild-to-moderate hypercholesterolemia. The dose of psyllium was between 3.0 and 20.4 g per day and intervention period was more than 2 weeks. Any type of diet background was permitted. Diet lead-in period was between 0 and 8 weeks.Results: Compared with placebo, consumption of psyllium lowered serum total cholesterol by 0.375 mmol/l (95% CI: 0.257-0.494 mmol/l), and LDL cholesterol by 0.278 mmol/l (95% CI: 0.213-0.312 mmol/l). With random-effect meta-regression, a significant dose-response relationship were found between doses (3-20.4 g/day) and total cholesterol or LDL cholesterol changes. Regression model of total cholesterol was À0.0222 þ 0.2061 Â log (dose þ 1), and that of LDL cholesterol was 0.0485 þ 0.1390 Â log (dose þ 1). There was a time effect of psyllium on total cholesterol (equation: 6.3640-0.0316 Â treatment period) and on LDL cholesterol (equation: 4.3134-0.0162 Â treatment period), suggesting that psyllium reduced serum total cholesterol more quickly than LDL cholesterol. Conclusions: Psyllium could produce dose-and time-dependent serum cholesterol-lowering effect in mild and moderate hypercholesterolemic patients and would be useful as an adjunct to dietary therapy for the treatment of hypercholesterolemia. (2009) 63, 821-827; doi:10.1038/ejcn.2008 published online 5 November 2008 Keywords: hypercholesterolemia; total cholesterol; LDL cholesterol; meta-analysis; randomized controlled trials European Journal of Clinical Nutrition IntroductionIn recent years, there has been growing interest in the use of dietary fibers in health maintenance and disease prevention (Petchetti et al., 2007). It has been speculated that a deficiency of soluble fibers in the Western diet might be contributing to the epidemics of coronary heart disease (CHD), diabetes mellitus and colonic cancer. Hypercholesterolemia has been identified as a prominent independent risk factor in the development of CHD. Soluble fibers, including those from psyllium husk, have been shown to augment the cholesterol-lowering effects of a low-fat diet in persons with hypercholesterolemia. Increasing dietary fiber has been recommended as a safe and practical approach for cholesterol reduction (NCEP ATPIII, 2001 andBrunner et al., 2007). Psyllium is one of the highest so...

Effects of psyllium on LDL-cholesterol concentrations in Brazilian children and adolescents: a randomised, placebo-controlled, parallel clinical trial

“…consumption of psyllium in conjunction with the NCEP Step 2 diet helps to maintain lower LDL-C concentrations without affecting HDL-C or TAG concentrations (7,10) . The 11 % (2 0·37 mmol/l) reduction in LDL-C concentrations observed in the present study is consistent with the results of previous psyllium trials in adults (7) , but higher than that recorded in short-term studies carried out previously in children and adolescents (9,23) .…”

“…It is derived from the seed husk of Plantago ovata (11) and is considered a useful supplement to dietary therapy (National Cholesterol Education Program (NCEP) Step 1 and 2 diets) for the treatment of hypercholesterolaemic patients. Despite this, Haney et al (12) and Spence et al (13) have expressed certain doubts with regard to the dose -response relationship and long-term efficacy of the treatment.Although these positive effects have been clearly demonstrated in hypercholesterolaemic adults (7) , there are few, mostly old, published studies on the use of psyllium or other fibre mixtures in children or adolescents (9,10) and some (13,14) have reported inconclusive results.We hypothesised that psyllium supplementation exerts an additional lipid-lowering effect on serum LDL-C concentrations in dyslipidaemic paediatric subjects treated with the NCEP Step 2 diet. * Corresponding author: Professor S. A. Ribas, fax þ55 21 2587 6494, email ribasnut@yahoo.com.br…”

“…A recent systematic review (7) has demonstrated the cholesterol-lowering capacity of the soluble dietary fibre extracted from psyllium husk in adults. Psyllium has been found to lead to reductions ranging from 2·78 to 2 22·8 % in the serum LDL-C concentrations of children and adolescents (8 -10) .…”

Dietary Supplements for Cholesterol Management

“…The meta-analysis that included 21 studies by Wei et al [45] reported that the use of psyllium (3-20.4 g/day) is associated with a lowering of total cholesterol by 14.5 mg/dL and LDL-cholesterol by 10.8 mg/dL in subjects with mild-to-moderate hypercholesterolemia. Based on their findings, the authors calculated that the consumption of psyllium 5, 10, 15 g/day could result in 5.6, 9.0, and 12.5 % decreases in LDL-cholesterol, respectively.…”

Effects of Glycemic Index and Intake of Dietary Fiber on Serum HDL-Cholesterol Levels

“…In three meta-analyses, data on effects of dietary fiber intake on HDL-C were not available [9][10][11]. Seven meta-analyses reported that intake of dietary fiber is not significantly associated with changes in HDL-C. Two meta-analyses described that HDL-C was significantly reduced, but only by a small amount [12,18].…”