Objective: To assess the effects of plant sterol or stanol ester consumption on their incorporation into erythrocytes and their effects on osmotic fragility of red blood cells.
Design: Double-blind, randomized, placebo-controlled intervention trial.
Subjects and intervention: Forty-one subjects on stable statin treatment - who already have increased serum plant sterol and stanol concentrations - first received for 4 weeks a control margarine. For the next 16 weeks, subjects were randomly assigned to one of three possible interventions. Eleven subjects continued with control margarine, 15 subjects with plant sterol ester enriched and 15 subjects with plant stanol ester-enriched margarine. Daily plant sterol or stanol intake was 2.5 g. Erythrocyte haemolysis was measured spectrophotometrically at five different saline concentrations.
Results: Despite significant (P = 0.004) increases of, respectively, 42 and 59% in cholesterol-standardized serum sitosterol and campesterol concentrations in the plant sterol group as compared to the control group, campesterol levels in the red blood cells did not change (P = 0.196). Osmotic fragility did not change significantly (P = 0.757) in the plant sterol and plant stanol groups as compared to the control group.
Conclusion: We conclude that plant sterol and stanol ester consumption for 16 weeks does not change osmotic fragility of erythrocytes in statin-treated patients.
Sponsorship: Netherlands Organisation for Health Research and Development (Program Nutrition: Health, Safety and Sustainability, Grant 014-12-010).