Effect of Yerba Mate (Ilex paraguariensis) on Lipid Levels: A Systematic Review and Meta-Analysis.

Several studies have evaluated the lipid-lowering properties of yerba mate, although the results were conflicting. The objective of this systematic review was to assess the effect of yerba mate consumption on lipid levels. A literature search was performed to detect observational and experimental studies that evaluated the association between yerba mate consumption and lipid levels. A quantitative analysis was performed with the subgroup of experimental studies. A meta-regression was performed considering the difference in baseline lipid values between the intervention and control groups as a covariate. Thirteen studies were considered eligible for this systematic review and seven studies (378 patients) were selected for quantitative analysis. In the qualitative analysis, the results were conflicting, both in the observational and in the experimental studies. In quantitative analysis, we found no differences in total cholesterol [mean difference 6.4 (CI 95% -2.2 to 15.0)], LDL-C [mean difference 5.5 (CI 95% - 1.5 to 12.6)], HDL-C [mean difference 0.4 (CI 95% -2.8 to 3.7)] and triglycerides [mean difference 5.7 (CI 95% 0.0 to 11.4)] levels when comparing the yerba mate and control groups. According to meta-regression, differences between baseline levels could influence the findings on total cholesterol and LDL-C but not on HDL-C or triglycerides. In conclusion, this research showed that yerba mate consumption was not associated with a significant change in lipid levels. Since the results are based on small inconclusive studies, more research is needed to confirm these findings.