Plant sterols and stanols inhibit intestinal cholesterol absorption and consequently lower serum LDL-cholesterol (LDL-C) concentrations. The underlying mechanisms are not yet known. In vitro and animal studies have suggested that changes in intestinal sterol metabolism are attributed to the LDL-C-lowering effects of plant stanol esters. However, similar studies in human subjects are lacking. Therefore, we examined the effects of an acute intake of plant stanol esters on gene expression profiles of the upper small intestine in healthy volunteers. In a double-blind cross-over design, fourteen healthy subjects (eight female and six male; age 21–55 years), with a BMI ranging from 21 to 29 kg/m2, received in random order a shake with or without plant stanol esters (4 g). At 5 h after consumption of the shake, biopsies were taken from the duodenum (around the papilla of Vater) and from the jejunum (20 cm distal from the papilla of Vater). Microarray analysis showed that the expression profiles of genes involved in sterol metabolism were not altered. Surprisingly, the pathways involved in T-cell functions were down-regulated in the jejunum. Furthermore, immunohistochemical analysis showed that the number of CD3 (cluster of differentiation number 3), CD4 (cluster of differentiation number 4) and Foxp3+ (forkhead box P3-positive) cells was reduced in the plant stanol ester condition compared with the control condition, which is in line with the microarray data. The physiological and functional consequences of the plant stanol ester-induced reduction of intestinal T-cell-based immune activity in healthy subjects deserve further investigation.

Clinical safety of consuming plant stanol ester spreads during pregnancy and lactation, the impact on maternal and infant serum and breast-milk cholesterol and the ratios (μmol/mmol of cholesterol) of synthesis and absorption markers were evaluated. Pregnant women (n 21) were randomised to control and dietary intervention groups, the intervention including advice to follow a balanced diet and to consume spreads enriched with plant stanol esters. Participants were followed during and after pregnancy and their infants up to 1 year of age. A mean 1·1 (sd 0·4) g consumption of plant stanols during pregnancy and 1·4 (sd 0·9) g 1 month post-partum increased sitostanol and the markers for cholesterol synthesis, lathosterol, lathosterol/campesterol and lathosterol/sitosterol, and reduced a marker for cholesterol absorption, campesterol, in maternal serum. In breast milk, desmosterol was lower in the intervention group, while no differences were detected between the groups in infants' serum. Plant stanol ester spread consumption had no impact on the length of gestation, infants' growth or serum β-carotene concentration at 1 and 6 months of age, but the cholesterol-adjusted serum β-carotene concentration was lowered at 1 month in the intervention group. Plant stanol ester spread consumption appeared safe in the clinical setting, except for potential lowering of infants' serum β-carotene concentration, and was reflected in the markers of cholesterol synthesis and absorption in mothers' serum, encouraging further studies in larger settings.

We evaluated whether plant stanol esters mixed with different vegetable oil spreads improved arterial health. A total of 200 adults with serum cholesterol >5 mmol/l were randomised to consume camelina, rapeseed or sunflower oil spread with stanol (2 g/d) ester or sunflower oil spread without stanol ester (controls) for 3 months. Non-invasive ultrasound was used to measure carotid artery compliance (CAC) and brachial artery flow-mediated endothelial dependent vasodilatation (FMD) at baseline and after the intervention as markers of arterial health. Plant stanol esters reduced LDL-cholesterol by 9 % compared with controls (P < 0·001) similarly in the different treatment groups. In the combined treatment groups (n 147), CAC or FMD were not changed from controls (n 47). In a subgroup analysis, division of subjects at baseline into below and over sex-specific 50th percentiles of CAC and FMD revealed that low CAC was improved from 1·23 to 1·59 % per 10 mmHg in the treatment group (n 69), and from 1·42 to 1·47 % per 10 mmHg in controls (n 25), (P = 0·0035 between groups). Low FMD was improved from 6·9 % to 8·6 % in the treatment group (n 73) and from 6·6 % to 6·8 % in controls (n 24) (P = 0·05 between groups). In the respective high-median groups, CAC and FMD were not changed in spite of significantly lowered LDL-cholesterol. In conclusion, consumption of plant stanol ester for 3 months had no overall significant effect on arterial elasticity and endothelial function. A controlled study is needed to test whether beneficial changes are obtained in subjects with initially reduced arterial elasticity and endothelial function.