Safety assessment of common foods enriched with natural nonesterified plant sterols.

BACKGROUND/OBJECTIVES: To assess safety during a diet based on low-fat foods enriched with nonesterified wood-derived plant sterols and mineral nutrients related to serum phytosterol, sex hormone and fat-soluble vitamin metabolism. SUBJECTS/METHODS: Seventy-one study participants (52 women, 19 men) with mild-to-moderate hypercholesterolemia completed the double-blind, placebo-controlled feeding trial lasting for 15 weeks. The subjects were randomly allocated to the sterol group receiving food items enriched with mineral nutrients as well as with a total of 1.25, 2.5 and 5.0 g per day of plant sterols during the first, second and third 5-week periods, respectively, or to the placebo group receiving similar food items without plant sterols. This outpatient clinical trial with free-living subjects was carried out at two hospital clinics. RESULTS: Two significant findings were observed. Serum sitosterol concentrations increased from 2.84 to 5.35 mg l(-1) (P<0.004 vs placebo) but those of serum total plant sterols did not because of compensatory changes in other phytosterols. The highest plant sterol levels did not exceed 0.6% of total serum sterols. Serum alpha-tocopherol concentrations decreased in the sterol group by 10% (P<0.0002), but the between-group difference disappeared after adjusting for the change in the carrier (LDL cholesterol). CONCLUSIONS: Fifteen-week consumption of natural nonesterified plant sterol-enriched food does not cause any serious adverse effects during such a period. However, serum alpha-tocopherol levels were somewhat reduced in the sterol group suggesting that long-term effects of plant sterols on serum fat-soluble vitamin concentrations should be further explored, especially in relation to very low-fat diets.

Safety aspects and cholesterol-lowering efficacy of low fat dairy products containing plant sterols.

OBJECTIVE: The aim of this study was to investigate whether a plant sterol mixture would reduce serum cholesterol when added to low fat dairy products in subjects with hypercholesterolaemia, and to examine the effects of the mixture on the serum plant sterol and fat-soluble vitamin levels. DESIGN: A parallel, double-blind study. SETTING: The study was performed in three different locations in Finland. SUBJECTS: In total, 164 mildly or moderately hypercholesterolaemic subjects participated in the study. METHODS: The subjects were randomly divided into two groups: a plant sterol group and a control group. The subjects consumed the products for 6 weeks after a 3-week run-in period. The targeted plant sterol intake was 2 g/day in the sterol group. RESULTS: During the treatment period, there was a 6.5% reduction in serum total cholesterol in the sterol group while no change was observed in the control group (P<0.0005). Serum low-density lipoprotein (LDL) cholesterol was reduced by 10.4% in the sterol group and by 0.6% in the control group (P<0.00005). There was no change during the trial in serum high-density lipoprotein (HDL) cholesterol or triacylglycerol concentrations. The HDL/LDL cholesterol ratio increased by 16.1% in the sterol group and by 4.3% in the control group (P=0.0001). Serum plant sterol levels increased significantly (P=0.0001) in the sterol group. None of the fat-soluble vitamin levels decreased significantly when changes in serum total cholesterol were taken into account. The hypocholesterolaemic effect of sterol administration was not influenced by apolipoprotein E phenotype. CONCLUSIONS: Yoghurt, low-fat hard cheese and low-fat fresh cheese enriched with a plant sterol mixture reduced serum cholesterol in hypercholesterolaemic subjects and no adverse effects were noted in the dietary control of hypercholesterolaemia.

Effect of a diet based on low-fat foods enriched with nonesterified plant sterols and mineral nutrients on serum cholesterol.

Plant sterols have been incorporated into nutritional fats to achieve cholesterol lowering, but studies using enrichment of low-fat foods with plant sterols have not been reported. Our study was aimed at determining the effect of dietary intake of low-fat foods containing natural nonesterified plant sterols together with recommended doses of calcium, magnesium, and potassium on serum cholesterol and low-density lipoprotein (LDL) cholesterol-lowering in persons with mild to moderate hypercholesterolemia. This was a randomized, double-blind, placebo-controlled feeding trial lasting 15 weeks and performed in 2 university hospital centers. Seventy-eight subjects aged 25 to 75 years with serum cholesterol concentrations varying between 6 mmol/L (232 mg/dl) and 8 mmol/L (310 mg/dl) were randomly allocated to active treatment consisting of intake of bread, meat products, and jam enriched with 1.25 to 5.0 g/day of plant sterols and the slightly elevated concentrations of mineral nutrients, or the corresponding placebo food items. Serum lipid, high-density lipoprotein cholesterol and calculated LDL cholesterol concentrations were determined. Seventy-one persons completed the trial. Reduction in serum total cholesterol was 8% in the active treatment group and 3% in the placebo group (p = 0.0071) and that of LDL cholesterol was 13% in the active treatment group and 5% in the placebo group (p = 0.0070). In conclusion, natural nonesterified plant sterols contained in low-fat food items and ingested in moderate doses reduced serum total and LDL cholesterol concentrations to the same extent as reported previously for esterified plant sterol derivatives added to nutritional fats. The presence of mineral nutrients in doses recommended for blood pressure-lowering did not interfere with the cholesterol-lowering efficacy of the sterols, providing a promising approach to dietary prevention of cardiovascular diseases.