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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 α-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 α-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.European Journal of Clinical Nutrition (2009) 63, 684–691; doi:10.1038/ejcn.2008.11; published online 13 February 2008 [ABSTRACT FROM AUTHOR]

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.European Journal of Clinical Nutrition (2006) 60, 633–642. doi:10.1038/sj.ejcn.1602362; published online 11 January 2006 [ABSTRACT FROM AUTHOR]

Objective:To clarify whether supplementation of vitamin E can alter the low density lipoprotein (LDL) oxidation properties and thereby affect endothelial cell function and prostacyclin production in smokers compared to nonsmokers on diets rich in fish in a pilot study.Design:The LDL of six smokers and six nonsmokers on habitual high fish diet was isolated before and after an 8-week supplementation of vitamin E (800 IU/day). LDL was oxidized by incubation with CuSO4. Cytotoxicity of LDL oxidized to different degrees on endothelial cells was investigated in vitro in these two groups.Setting:Helsinki University Central Hospital; Institute of Biomedicine, Pharmacology, University of Helsinki.Results:At baseline, the rate of oxidation was higher in nonsmokers than in smokers. The lag phase increased significantly after the supplementation of vitamin E both in smokers and nonsmokers. Native LDL dose dependently tended to reduce the viability of endothelial cells in vitro more markedly when isolated from smokers than from nonsmokers. Vitamin E supplementation had no beneficial effect on the cytotoxicity of oxidized LDLs in endothelial cell culture. On the other hand, simultaneous administration of Trolox®, the water-soluble analogue of vitamin E, attenuated the LDL cytotoxicity on endothelial cells. The vitamin E supplementation to LDL donors attenuated the increase in prostacyclin production both in smokers and nonsmokers.Conclusion:Supplementation of LDL donors (healthy male volunteers on habitual fish diet) with vitamin E increased the lag phase of LDL oxidation, but, on the other hand, did not influence in vitro cytotoxicity of LDL, or prostacyclin production.Sponsorship:Helsinki University Central Hospital and Biomed 2.European Journal of Clinical Nutrition (2005) 59, 1282–1290. doi:10.1038/sj.ejcn.1602241; published online 27 July 2005 [ABSTRACT FROM AUTHOR]

Objective: To study, if there are differences in the fatty acid composition of low-density lipoprotein (LDL) in people eating three different long-standing habitual diets: vegetarian, high fish intake, or high saturated fat (milk fat) diet as a control group, and to study if these differences influence the oxidation susceptibility of LDL.Design: Cross-sectional study using blood samples and a validated dietary frequency questionnaire with illustrations.Setting: Helsinki University Central Hospital, Finland.Subjects: The effect of three different types of long-standing diets of different fatty acid content (a strict vegetarian diet, n=11; a high fish intake diet, n=9; and a high saturated fat (milk fat) diet, controls, n=7) on the serum and LDL fatty acid content, and on the susceptibility of LDL to oxidation in vitro, was studied in healthy normocholesterolemic volunteers who had been on these diets for years. Oxidation of LDL was carried out by using CuSO4 as a pro-oxidant.Results: There were no statistically significant differences in the serum lipids or lipoproteins, though the vegetarian group exhibited lowest mean values of total, high-density lipoprotein (HDL) and LDL cholesterol levels. Both the serum and LDL eicosapentaenoic, docosapentaenoic and docosahexaenoic acid proportions were highest in the fish and lowest in the vegetarian groups. Linoleic acid was highest among the vegetarians. In the fish group, the vitamin A concentration in serum was higher than in vegetarians and controls and beta-carotene lower than in controls, but in alpha-tocopherol, or lycopene concentrations there were no statistically significant differences. The lag phase of LDL oxidation was shortest (116 min) in the fish group and longest (165 min) in the vegetarian group, and the control group was between them (129 min). The mean oxidation percentage after 2.5 h of copper-induced oxidation was highest (44%) in the fish group and lowest (22%) in the vegetarian group and intermediate (31%) in the control group.Conclusion: Long-term dietary habits predict the fatty acid composition of serum and LDL, and influence the susceptibility of LDL to oxidation. In the fish group with the highest content of omega-3 fatty acids in LDL, the oxidation susceptibility of LDL was highest. In the vegetarian group with less omega-3 fatty acids in LDL, the LDL was more resistant to oxidation.Sponsorship: Helsinki University Central Hospital. [ABSTRACT FROM AUTHOR]