Recommended phytosterol intake predicted to reduce LDL cholesterol by 9%, meta-analysis shows
- Meta-analysis of 84 randomized, controlled trials involving over 6,800 participants
- Dose-response curves predicts absolute (mmol/L) and relative (%) effect of phytosterols on LDL cholesterol
- Recommend daily dosage of phytosterols (2 g) expected to lower LDL cholesterol by 0.35 mmol/L or by 9%
This meta-analysis was performed to establish a continuous dose-response curve to predict the ability of different phytosterols dosages to reduce blood levels of low-density lipoprotein (LDL) cholesterol.
Inclusion criteria included randomized, placebo-controlled trials involving adults (parallel-arm or cross-over trials) with typical phytosterols treatment (not more than 10 g/day) lasting 2 weeks or longer and with blood lipids as a primary or secondary outcome measure with sufficient data reported. Studies with other interventions that could confound the effects of the intake of phytosterols were excluded.
A nonlinear equation using the maximal LDL cholesterol-lowering effect and an incremental dose step was used to describe the dose-response curve. The overall pooled absolute (mmol/L) and relative (%) LDL cholesterol-lowering effects of phytosterols were also assessed with a random effects model.
A total of 84 trials (141 trial arms) with 6,805 participants were included in the analysis.
Results indicate that a mean daily dose of 2.15 g phytosterols resulted in a pooled LDL cholesterol reduction and confidence interval (CI) of 0.34 mmol/L (95% CI: -0.36, -0.31) and 8.8% (95% CI: -9.4, -8.3).
Subgroup analyses found no significant differences between dose-response curves established for plant sterols vs. stanols, fat-based vs. non fat-based food formats and dairy vs. nondairy foods.
However, subgroup analyses revealed that a higher baseline LDL-C level resulted in greater absolute LDL cholesterol reductions. A larger effect was observed with solid vs. liquid foods, but only at high dosages of phytosterols exceeding 2 g/day. A tendency (P=.054) towards slightly lower efficacy of single vs. multiple daily intakes of phytosterols was also reported.
These findings indicate that a dose-response relationship predicts that the recommended daily dosage of phytosterols (2 g/day) would be expected to lower LDL cholesterol by 0.35 mmol/L or by 9%.