Role of plant stanol ester- and sterol ester-enriched margarines in the treatment of hypercholesterolemia.

Maarit Hallikainen,

Department of Clinical Nutrition,University of Kuopio and Kuopio University Hospital.

The effects of plant stanol esters or sterol esters on serum lipids and lipoprotein lipids, serum fat-soluble vitamins and carotenoids, serum cholesterol precursors as well as serum plant sterols and stanols were examined in mildly or moderately hypercholesterolemic men and women.

Study I/II utilized a parallel study design, studies III/IV and V involved a repeated measures design.

In study I/II 55 subjects were randomized after a 4-week baseline, high-fat, diet period into three experimental groups ingesting three low-fat margarines: wood stanol ester (WSEM), vegetable oil stanol ester (VOSEM) and control. The groups consumed the margarines for eight weeks as part of a low-fat, low-cholesterol diet.

In study III/IV, each of 22 subjects consumed five different doses of plant stanol [target (actual) intake 0 (0), 0.8 (0.8), 1.6 (1.6), 2.4 (2.3), 3.2 (3.1) g/day]- added as stanol esters to margarine for four weeks as part of a standardized habitual diet. The order of dose periods was randomly determined.

In study V, 34 subjects consumed stanol ester (STAEST), sterol ester (STEEST) and control margarines as part of a cholesterol-lowering diet each for four weeks. The randomization was performed according to the Latin square model. In study I, the low-fat WSEM and VOSEM margarines reduced serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) as part of a cholesterol-lowering diet significantly by 16-18% and 18-24%, respectively, from a high-fat baseline diet. An additional approximately 10% cholesterol-lowering effect of these margarines compared with the low-fat diet (control) was noted (I). There was no significant difference in the cholesterol-lowering efficacy between these test margarines (I).

Study III showed that the effect of plant stanol esters on serum TC and LDL-C is dose-dependent. A significant reduction in serum TC and LDL-C was achieved with the stanol dose of 1.6 g/d, and increasing the dose from 2.4 g/d to 3.2 g/d did not offer additional cholesterol-lowering effect.

In study V, no significant differences between the STAEST and STEEST margarines with respect to efficacy in reducing serum TC (9.2% vs. 7.3%, compared with control) and LDL-C (12.7% vs. 10.4%) in short-term were found. Plant stanol esters or sterol esters did not affect serum fat-soluble vitamins (I, III, V). Their impact on serum carotenoids was minor (I/II, III, V) when the dietary intake of vegetables was ensured. Plant stanol esters reduced serum plant sterol concentrations significantly already with the stanol dose of 0.8 g/d (III/IV) indicating that cholesterol absorption was effectively inhibited already with the small stanol ester doses.

The findings of serum D7-lathosterol/TC ratio (an indirect indicator of cholesterol synthesis) indicated that cholesterol synthesis was stimulated by a stanol dose of 0.8 g/d, but no further increase was observed when the stanol dose was higher than 1.6 g/d (IV). The consumption of plant stanol esters increased serum sitostanol and campestanol concentrations by about twofold, but the concentrations remained extremely low, and they plateaued with a dose equal to or greater than the 0.8 g/d (III/IV). In conclusion, plant stanol ester- and sterol ester-enriched margarines are an effective and safe way to achieve a reduction in serum cholesterol when they are consumed as part of a low-fat, low-cholesterol diet. The optimal dose of stanol ester is 1.6-2.4 g/d of stanols.