Effects of a diet high in plant sterols, vegetable proteins, and viscous fibers (Dietary Portfolio) on circulating sterol levels and red cell fragility in hypercholesterolemic subjects

Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
Lipids (Impact Factor: 1.85). 03/2005; 40(2):169-74. DOI: 10.1007/s11745-005-1372-6
Source: PubMed


Plant sterols, soy proteins, viscous fibers, and nuts are advised for cholesterol reduction, but their combined effect on plant sterol absorption has never been tested. We assessed their combined action on serum sterols in hyperlipidemic subjects who were following low-saturated fat diets before starting the study and who returned to these diets post-test. The 1-mon test (combination) diet was high in plant sterols (1 g/1,000 kcal), soy protein (23 g/1,000 kcal), viscous fiber (9 g/1,000 kcal), and almonds (14 g/1000 kcal). Fasting blood was obtained for serum lipids and sterols, and erythrocytes were obtained for fragility prior to and at 2-wk intervals during the study. The combination diet raised serum campesterol concentrations by 50% and beta-sitosterol by 27%, although these changes were not significant after Bonferroni correction; near-maximal rises were found by the end of the first week, but no change was found in red cell fragility despite a 29% reduction in the LDL cholesterol level. No significant associations were observed between changes in red cell fragility and blood lipids or sterols. We conclude that plant sterols had a minimal impact on serum sterol concentrations or red cell fragility in hyperlipidemic subjects on diets that greatly reduced their serum lipids.

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    • "Plant sterols have been suggested to increase red cell fragility or to reduce deformability in studies of spontaneously hypertensive stroke prone rats (Naito et al., 2000; Ratnayake et al., 2000). The current data demonstrate a significant effect only when the red cell fragility change was compared as a percentage and other human studies have failed to show an increase in red cell fragility or changes in hematological indices with plant sterols (Hendriks et al., 2003; De Jong et al., 2004; Jones et al., 2005). Small changes in red cell fragility within the physiological range may be part of the explanation for the equally small changes in Hb, although no direct correlation was observed. "
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