Alpha lipoic acid supplementation improves blood lipid profile in adults, meta-analysis shows
Highlights
- Meta-analysis of 11 randomized, controlled trials involving 452 adults
- ALA supplementation ranges from 300 to 600 mg/day
- Study duration ranges from 2 to 20 weeks
- ALA significantly reduces serum levels of triglycerides, total cholesterol and LDL cholesterol without affecting HDL cholesterol.
Summary
This systematic review and meta-analysis was conducted to summarize the available clinical trials examining the effect of alpha lipoic acid (ALA) supplementation on the blood lipid profile of adults.
A systematic search was carried out on clinical trials (English language) published in PubMed and Scopus up to April 2017. Inclusion criteria included controlled clinical trials involving adults with oral ALA supplementation and reported lipid profile parameters after intervention. Exclusion criteria included studies that also investigated effects of other interventions, had no control/placebo group, reported incomplete data, or were observational studies such as case-control or cohort studies.
Results are reported as the weighted mean difference (WMD) with 95% confidence intervals (CI) using a random effects model. Heterogeneity was assessed with I-squared (I2) and Cochrane’s Q tests. Publication bias and subgroup analyses were also performed.
A total of 11 clinical trials with 452 adults (51.5% women, 48.5% men) met the inclusion criteria and were included in the meta-analysis. The duration of study interventions varied from 2 to 20 weeks, and ALA dosages ranged from 300 to 600 g/day.
Results indicate that ALA supplementation significantly reduced serum triglyceride (TG) level compared to placebo (weighted mean difference [WMD], -29.185 mg/dL; 95% confidence interval [CI], -51.454 to -6.916; P=.010). ALA supplementation also significantly reduced serum total cholesterol and LDL cholesterol (WMD, -10.683 mg/dL; 95% CI, -19.816 to -1.550; P=.022; WMD, -12.906 mg/dL; 95% CI, -22.133 to -3.679; P=.006, respectively). Significant changes were not observed in serum HDL cholesterol (WMD, -0.092 mg/dL; 95% CI, -3.014 to 2.831; P=.025).
The authors report potential sources of heterogeneity as ALA dosage and body mass index (BMI). Those with a BMI over 30 kg/m2 who received more than 600 mg/day ALA showed better improvements in lipid profile.
These findings indicate that ALA supplementation (300 to 600 mg/day for 2 to 20 weeks) may offer clinical value to improve blood lipid profiles in adults by reducing serum levels of TG, total cholesterol and LDL cholesterol without affecting HDL cholesterol.
