The effects of plant stanol ester consumption on arterial stiffness and endothelial function in adults: a randomised controlled clinical trial

BACKGROUND: The hypocholesterolemic effect of plant stanol ester consumption has been studied extensively, but its effect on cardiovascular health has been less frequently investigated. We studied the effects of plant stanol esters (staest) on arterial stiffness and endothelial function in adults without lipid medication. METHODS: Ninety-two asymptomatic subjects, 35 men and 57 women, mean age of 50.8±1.0 years (SEM) were recruited from different commercial companies. It was randomized, controlled, double-blind, parallel trial and lasted 6 months. The staest group (n=46) consumed rapeseed oil-based spread enriched with staest (3.0 g of plant stanols/d), and controls (n=46) the same spread without staest. Arterial stiffness was assessed via the cardio-ankle vascular index (CAVI) in large and as an augmentation index (AI) in peripheral arteries, and endothelial function as reactive hyperemia index (RHI). Lipids and vascular endpoints were tested using analysis of variance for repeated measurements. RESULTS: At baseline, 28% of subjects had a normal LDL cholesterol level (≤3.0 mmol/l) and normal arterial stiffness (<8). After the intervention, in the staest group, serum total, LDL, and non-HDL cholesterol concentrations declined by 6.6, 10.2, and 10.6% compared with controls (p<0.001 for all). CAVI was unchanged in the whole study group, but in control men, CAVI tended to increase by 3.1% (p=0.06) but was unchanged in the staest men, thus the difference in the changes between groups was statistically significant (p=0.023). AI was unchanged in staest (1.96±2.47, NS) but increased by 3.30±1.83 in controls (p=0.034) i.e. the groups differed from each other (p=0.046). The reduction in LDL and non-HDL cholesterol levels achieved by staest was related to the improvement in RHI (r=−0.452, p=0.006 and −0.436, p=0.008). CONCLUSIONS: Lowering LDL and non-HDL cholesterol by 10% with staest for 6 months reduced arterial stiffness in small arteries. In subgroup analyses, staest also had a beneficial effect on arterial stiffness in large arteries in men and on endothelial function. Further research will be needed to confirm these results in different populations. TRIAL REGISTRATION: Clinical Trials Register # NCT01315964