Background: Plant sterol (PS) supplementation is increasingly accepted as a dietary strategy to lower plasma cholesterol concentrations. However, information is scarce about the effect of increased PS intake in potentially vulnerable groups, such as phytosterolemia heterozygotes (HET).
Objective: This study assessed the responsiveness of circulating PS and lipid concentrations and cholesterol kinetics (absorption and synthesis) to daily PS supplementation in HET (ABCG8 S107X mutation) compared with a healthy control cohort.
Design: A double-blind, randomized, crossover, placebo-controlled study was conducted in 10 HET and 15 control subjects. The participants had a mean (±SEM) age of 34 ± 2 y and a BMI (in kg/m²) of 29.9 ± 1.1 and consumed ∼1.6 g PS or placebo capsules daily with supper for 4 wk. Cholesterol absorption and synthesis were assessed by using [¹³C]cholesterol and deuterium oxide, respectively.
Results: Plasma LDL-cholesterol concentrations decreased (P = 0.006) in both groups after PS supplementation (HET: 2.73 ± 0.19 mmol/L; control: 3.11 ± 0.19 mmol/L) compared with placebo (HET: 3.12 ± 0.20 mmol/L; control: 3.50 ± 0.21 mmol/L), whereas PS concentrations (campesterol+β-sitosterol) increased (P = 0.03) in both groups after PS supplementation (HET: 39.72 ± 6.05 μmol/L; control: 24.03 ± 1.65 μmol/L) compared with placebo (HET: 27.32 ± 3.80 μmol/L; control: 21.12 ± 2.05 μmol/L). Cholesterol absorption efficiency decreased (P = 0.010) by ∼22% and ∼17% and synthesis rates increased (P = 0.040) by ∼20% and ∼24% in the HET and control groups, respectively, in response to PS consumption compared with placebo.
Conclusion: These data suggest that heterozygosity for the ABCG8 S107X mutation does not influence the action of dietary PS on circulating cholesterol concentrations but may affect sterol absorption.
Trial registration: ClinicalTrials.gov NCT01102647.