Objective: Plant sterols (PS) consumed as a snack may not have the same cholesterol-lowering potential as when consumed with a meal due to poor solubilization. It was hypothesized that the consumption of a single dose, low-fat yogurt rich in PS (1.6 g/d) with a meal over an afternoon snack will lead to favourable changes in plasma lipids, plasma PS concentrations, and cholesterol synthesis without negatively affecting alpha-tocopherol or carotenoids levels.
Methods: Twenty-six hyperlipidemic males and females completed the randomized trial of three phases (control, single PS dose consumed with a meal, or single PS dose as an afternoon snack) while consuming controlled, low-fat diets. Plasma lipids, cholesterol synthesis rates, plasma PS and serum fat-soluble antioxidants were measured at baseline and after 4 weeks.
Results: Endpoint total cholesterol (TC) levels after the PS snack phase were decreased (p = 0.04) (5.30 +/- 0.2 mmol/L) compared to the control phase (5.53 +/- 0.2 mmol/L). However, endpoints for TC (5.37 +/- 0.2 mmol/L) for PS dose with a meal were comparable to control phase. Low-density lipoprotein-cholesterol tended to be different (p = 0.06) at the end of the intervention phases (3.51 +/- 0.1, 3.43 +/- 0.1, and 3.33 +/- 0.1 mmol/L; control, meal and snack, respectively). Cholesterol fractional synthesis rates were higher (p = 0.007) by 25.8% and 19.5% at the end of the snack and meal phases, respectively, compared with the control phase. Plasma campesterol and beta-sitosterol concentrations, adjusted for TC, were higher (p < 0.01) in the snack phase (2.30 +/- 0.3 and 0.54 +/- 0.1 micromol/mmol, respectively) and in the meal phase (2.00 +/- 0.3 and 0.51 +/- 0.1 micromol/mmol, respectively) when compared to the control phase (1.81 +/- 0.3 and 0.40 +/- 0.1 micromol/mmol, respectively). No changes in alpha-tocopherol or carotenoids levels were detected after adjusting for TC, for all phases.
Conclusion: These results indicate that a single dose of PS in low-fat yogurt, provided as a snack, lowers cholesterol levels but does not alter fat-soluble vitamin or carotenoid concentrations in hyperlipidemic participants.