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Ym3.5

Yerba Mate Research

Mostly mechanism / observationalModerate safety

5 peer-reviewed studies

What the evidence says

Mostly mechanism / observational

Most Yerba Mate studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.

Most evidence is from medium-quality meta-analyses and randomised trials published 2014–2025 with a typical study size of 92 participants.

Based on 5 studies · 1 meta-analysis · 2 RCTs · 4,751 total participants

Confidence

Moderate

By outcome

Weight managementSmall reductions in body-fat mass and waist-hip ratio in one 12-week RCT; meta-analysis found weight/BMI effects 'limited' · 8-12 weeks
Too few graded studies2 studies
Safety profile
Too few graded studies2 studies

Steady research

1 study in the last 5 years · Latest meta-analysis: 2025

201420192025

1Meta-Analysis2025

Yerba Maté consumption may demonstrate favorable effects on glycemic control, though its impact on lipid profiles and weight management appears to be limited.

Li D et al. · Front Endocrinol (Lausanne) (2025)

Pooled 13 RCTs; in pre-diabetic subjects found lower postprandial glucose (MD -12.76), HbA1c (MD -0.37), and HOMA index (MD -0.24)
NO significant effect on triglycerides, total/HDL/LDL cholesterol, fasting glucose, fasting insulin, waist circumference, or BMI
Reported adverse events included insomnia, tachycardia, angina, headache, GI discomfort, and mucosal irritation

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2Case-Controln=4,629 · very large study2014

Odds ratios for esophageal squamous cell carcinoma increased linearly with cumulative maté consumption and were higher with hotter beverage temperatures.

Lubin JH et al. · Cancer Epidemiol Biomarkers Prev (2014)

Pooled case-control data: 1,400 cases and 3,229 controls
Ever-use OR 1.60 (95% CI 1.2-2.2); risk rose linearly with cumulative consumption
Strength of association increased with higher mate temperature (a key, modifiable safety factor)

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3RCTn=30 · small study2015

Yerba Mate supplementation decreased body fat mass, percent body fat and WHR without significant adverse effects.

Kim SY et al. · BMC Complement Altern Med (2015)

12 weeks of 3 g/day yerba mate vs placebo in obese adults
Significant reductions in body-fat mass (P=0.036), percent body fat (P=0.030), and waist-hip ratio (P=0.004)
Small trial (n=30); no clinically significant safety changes

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4Systematic Review2019

Commercial mate samples, often smoke-dried, frequently contained high levels of carcinogenic polycyclic aromatic hydrocarbons.

Oranuba E et al. · J Environ Sci Health C Environ Carcinog Ecotoxicol Rev (2019)

Reviewed 10 articles measuring PAHs in dry mate; most found benzo[a]pyrene over 25 ng/g, some up to 600 ng/g
Transfer of PAHs into the infusion varied 1-50% depending on method
Provides a second plausible carcinogenic mechanism (chemical contamination) beyond thermal injury

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5Crossovern=92 · small study2017

Mate tea did not significantly improve the lipid profile; only dark chocolate raised HDL-C in this crossover trial.

Souza SJ et al. · Nutrition (2017)

Randomized double-blind placebo-controlled crossover, 92 patients, 3 g mate tea for 15 days
Mate tea showed no significant lipid improvement (the HDL-C benefit was attributed to dark chocolate, not mate)
Illustrates the inconsistency of mate's lipid effects in controlled settings

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View in Research Library

Yerba Mate Research

Mostly mechanism / observational

Yerba Maté and its impact on glycemic control and metabolic health: a systematic review and meta-analysis.

Maté drinking and esophageal squamous cell carcinoma in South America: pooled results from two large multicenter case-control studies.

Anti-obesity effects of Yerba Mate (Ilex Paraguariensis): a randomized, double-blind, placebo-controlled clinical trial.

Polycyclic aromatic hydrocarbons as a potential source of carcinogenicity of mate.

Effect of chocolate and mate tea on the lipid profile of individuals with HIV/AIDS on antiretroviral therapy: A clinical trial.