José · Nutrition reviews 2023 · systematic review · n=32 studies

Physiological effects of yerba maté (Ilex paraguariensis): a systematic review.

Level 1 - systematic review of randomized trials

Systematic review including randomized controlled trials, nonrandomized trials, and observational studies

PubMed 36647770 · doi:10.1093/nutrit/nuac109 · record verified 2026-08-26

What was done

Authors searched six electronic databases (PubMed, Embase, Scopus, Web of Science, SciELO, LILACS) and three grey literature databases for randomized trials, nonrandomized trials, and observational studies evaluating the physiological effects of yerba maté (*Ilex paraguariensis*). Risk of bias was evaluated using Cochrane tools (RoB and ROBINS-I) and Joanna Briggs Institute critical appraisal instruments. Evidence certainty was rated using GRADE.

What was found

Thirty-two studies were included from 1,096 identified records. The abstract reports no quantitative pooled effect sizes or numeric metrics. Qualitatively, studies reported consistent benefits on metabolism, antioxidant and anti-inflammatory activity, body weight and composition, exercise performance, mood, appetite, and cardiovascular and neuroprotective markers. Of the 32 studies, risk of bias was rated as high in 22, moderate in 9, and low in 1. GRADE certainty of evidence ranged from moderate to very low.

Why it matters

This review aggregates clinical and observational evidence for yerba maté's metabolic and physiological effects, establishing potential therapeutic roles while highlighting substantial methodological shortcomings in existing trials.

Limits

The abstract reports no numerical effect sizes or meta-analytic estimates. The primary evidence base is constrained by poor methodological rigor, with 22 of 32 studies carrying a high risk of bias, only 1 low-risk study, and overall evidence certainty ranging from moderate to very low.

Cited by