Supplement analysis backed by scientific evidence · PT

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Limited evidenceHeart & metabolic

Yerba Mate

A caffeinated polyphenol-rich tea with modest, inconsistent effects on blood lipids and no convincing weight-loss data. The more important finding in the literature is a consistent association between heavy, very hot mate drinking and oesophageal cancer.

What the science says

  • Blood lipids and cardiometabolic markers Limited evidence

    A randomized crossover study of standardized mate extract in men at cardiovascular risk found modest reductions in LDL cholesterol and improvements in oxidative-stress markers over several weeks. Other controlled trials, including comparisons with green tea in dyslipidaemic overweight patients, have produced mixed results, and effect sizes are small relative to established lipid therapy.

  • Weight loss and fat oxidation Limited evidence

    Acute studies show mate raises fat oxidation during exercise, which is expected from its caffeine content, but trials measuring actual body weight or fat mass over weeks are few, small and largely unconvincing. There is no adequately powered RCT supporting mate as a weight-loss intervention.

  • Oesophageal cancer risk Moderate evidence

    A meta-analysis of observational studies found mate drinking significantly associated with oesophageal squamous cell carcinoma, with risk rising with amount consumed. The mechanism appears to be primarily thermal injury from drinking at very high temperature: the IARC classifies very hot beverages above 65 C as probably carcinogenic to humans, while mate drunk at moderate temperature is not classified as carcinogenic.

  • Alertness and mental performance Limited evidence

    Mate contains roughly 30-90 mg caffeine per cup plus theobromine, and produces the alertness you would expect from that dose. Claims of a uniquely smooth or jitter-free stimulation from its saponins are marketing, not trial findings.

Dosage & safety

Studied doseTraditional consumption is 0.5-1 L of infusion per day from roughly 50 g of leaves, refilled repeatedly. Clinical studies used 1-3 g/day of dried leaf or standardized extract. If you drink it, let it cool below about 60-65 C before the first sip.
SafetyThe main effects are caffeine-related: insomnia, anxiety, palpitations and raised blood pressure. Heavy long-term consumption is associated with oesophageal, laryngeal and oral cancers, an association strongest for very hot and high-volume drinking and amplified by smoking and alcohol. Traditionally smoke-dried mate can carry polycyclic aromatic hydrocarbons; air-dried products reduce this exposure. Mate has mild MAO-inhibitory activity in vitro, so avoid combining with MAOIs, and keep total caffeine under about 200 mg/day in pregnancy. Interacts with stimulants, theophylline and fluvoxamine.

Scientific references

Where to buy

Source Naturals, Yerba Mate, 600 mg, 90 Tablets

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