Abstract and Introduction
Abstract
Study Objective: To compare the efficacy and safety
of plant sterols and stanols as well as policosanol in the
treatment of coronary heart disease, as measured by a
reduction in low-density lipoprotein cholesterol (LDL)
levels.
Design: Systematic review and meta-analysis
of randomized controlled trials.
Patients: A total
of 4596 patients from 52 eligible studies.
Measurements
and Main Results: We searched MEDLINE, EMBASE, the Web of
Science, and the Cochrane Library from January 1967-June 2003
to identify pertinent studies. Reduction of LDL levels was the
primary end point; effects on other lipid parameters and
withdrawal of study patients due to adverse effects were the
secondary end points. Weighted estimates of percent change in
LDL were -11.0% for plant sterol and stanol esters 3.4 g/day
(range 2-9 g/day [893 patients]) versus -2.3% for placebo (769
patients) in 23 eligible studies, compared with -23.7% for
policosanol 12 mg/day (range 5-40 mg/day [1528 patients])
versus -0.11% for placebo (1406 patients) in 29 eligible
studies. Cumulative p values were significantly different from
placebo for both (p<0.0001). The net LDL reduction in the
treatment groups minus that in the placebo groups was greater
with policosanol than plant sterols and stanols (-24% versus
-10%, p<0.0001). Policosanol also affected total
cholesterol, high-density lipoprotein cholesterol (HDL), and
triglyceride levels more favorably than plant sterols and
stanols. Policosanol caused a clinically significant decrease
in the LDL:HDL ratio. Pooled withdrawal rate due to adverse
effects and combined relative risk for patients who withdrew
were 0% and 0.84, respectively (95% confidence interval [CI]
0.36-1.95, p=0.69), for plant sterols and stanols across 20
studies versus 0.86% and 0.31, respectively (95% CI 0.20-0.48,
p<0.0001), for policosanol across 28
studies.
Conclusion: Plant sterols and stanols and
policosanol are well tolerated and safe; however, policosanol
is more effective than plant sterols and stanols for LDL level
reduction and more favorably alters the lipid profile,
approaching antilipemic drug efficacy.
Introduction
Coronary heart disease (CHD) remains the leading cause of
death in industrialized nations. Elevated low-density
lipoprotein cholesterol (LDL) level is a major risk factor for
CHD, hence it is the primary target of lipid-lowering
therapy.[1] Due to concerns regarding adverse
effects and patient reluctance to comply with chemically
derived drug therapies, alternative natural therapies have
become increasingly popular over the last
decade.[2,3]
Plant (phyto) sterols are naturally occurring cholesterol
derivatives (e.g., sitosterol, campesterol, brassicasterol,
stigmasterol) from vegetable oils, nuts, soy, corn, woods, and
beans. Hydrogenation of plant sterols produces stanols.
Esterification produces sterol and/or stanol esters. The
generic term phytosterols often is used to describe both
sterols and stanols and their esters. The LDL-lowering
efficacy of plant stanols is considered comparable with that
of plant sterols.[4-8] The United States National
Cholesterol Education Program (NCEP) Adult Treatment Panel
(ATP) III endorses plant sterol and stanol esters 2 g/day as
an essential feature of therapeutic lifestyle changes along
with diet modifications, weight reduction, intake of viscous
fibers, and increased physical activity to reduce risk for
CHD.[1]
Another natural product, policosanol, is an antilipemic
agent that includes mixtures of aliphatic primary alcohols
extracted from sugarcane ( Saccharum officinarum L)
wax. Its main components are octacosanol (62.9%), triacontanol
(12.6%), and hexacosanol (6.2%).[9] Policosanol is
used for reduction of LDL levels in more than 25 countries,
mainly in the Caribbean and South America. Clinical studies
have demonstrated consistent LDL-lowering activity of
policosanol without apparent toxicity
concerns.[9,10]
