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 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]