Yerba Mate

Publication Details

OVERVIEW

Introduction

Yerba mate is a caffeinated herbal drink popular in South America that is used much like coffee or tea as a refreshing and stimulating beverage. It has recently become popular in the United States and Europe as a drink as well as a component of multiingredient dietary supplements. Yerba mate is generally regarded as safe and despite broad scale use has been recently linked to rare instances of clinically apparent liver injury.

Background

Yerba mate is prepared from the leaves and small stems of the evergreen tree, Ilex paraguariensis, that is native to Paraguay, Uruguay, and parts of Brazil and Argentina. Yerba mate as a beverage was first used by the native Guarani people and was later popularized by missionary Jesuits in the area which led to a more widespread use. Yerba mate is now a popular drink in South America prepared as tea or as a cold soft drink sold in bottles and cans. More recently, it has become a popular herbal drink in the United States and in Europe as well as a component in multiingredient herbal products. In preparation of Yerba mate, the leaves are typically baked, dried, and ground into a powder that may be flavored with citrus fruit or other flavoring substances and sold as a powder for preparing tea or made into a drinkable form and sold in bottles or cans. Yerba mate has multiple methylxanthines including caffeine, theobromine, and theophylline, and drinks made from the herb typically have concentrations of caffeine similar to those in tea and coffee. In addition, Yerba mate has polyphenols that are believed to be antioxidants as well as flavonoids (such as rutin and quercetin), anthocyanins, triterpene saponins, phytosterols, amino acids, minerals, and vitamins. Yerba mate is claimed to increase vitality and mental concentration and to decrease hunger. It is also purported to improve serum lipids, cause weight loss, decrease inflammation, benefit cardiovascular health, and even to prevent liver injury. The levels of caffeine may explain some of the effects found with Yerba mate, but the health promoting properties are usually attributed to its other components. The general health claims made for Yerba mate, however, have not been shown in rigorously controlled and adequately powered clinical trials, and it is not approved in the United States as therapy for any disease or condition. Nevertheless, Yerba mate is widely available as a powdered extract and as canned or bottled liquid drinks. Yerba mate extracts also are found in multiingredient dietary supplements, typically advertised as helpful for weight loss and for metabolic health, well-being, and longevity. The typical dose ranges widely and is difficult to estimate but is probably in the range of 1 to 3 grams daily. Side effects are uncommon but with excessive intake, caffeine related adverse events such as palpitations, nervousness, headache, and insomnia may arise. Epidemiologic studies suggest that long term use of Yerba mate may increase the risk of head and neck cancers.

Hepatotoxicity

In small, short term clinical studies of different preparations and concentrations of Yerba mate, adverse side effects were usually described as absent or minimal with no mention of hepatotoxicity. Typical tests for liver and kidney injury or dysfunction were unchanged and normal. Despite these findings and its long history of use, Yerba mate has been implicated in causing liver injury in a few published cases. Details of the liver injury have not been well defined. In a recent case report, a 21 year old American man developed jaundice and itching after 4 months of drinking Yerba mate daily while visiting Argentina. The injury was strikingly hepatocellular with ALT and AST values more than 50 times the upper limit of normal (ULN), but alkaline phosphatase less than twice ULN, despite a bilirubin above 30 mg/dL. All known causes of acute hepatitis were excluded. Immune allergic symptoms (fever and rash) were not present and liver biopsy showed an acute hepatitis with cholestasis. The patient recovered without treatment within 2 months of stopping the herbal drink. While unusual, the case report was reasonably convincing as no other cause was evident, and improvement followed stopping the herbal drink. Thus, liver injury from Yerba mate might be considered possible but is exceedingly rare.

Likelihood score: D (possible but rare cause of clinically apparent liver injury).

Mechanism of Injury

Yerba mate has multiple constituents, and the chemical compound responsible for liver injury is not known. The clinical features of the single case of Yerba mate associated liver injury suggest that it was immunologically mediated. The injury resembled that of green tea or turmeric associated liver injury which are believed to be caused by polyphenols.

Outcome and Management

The single carefully described case of liver injury from Yerba mate resolved spontaneously and completely once the herbal drink was discontinued. There is no information on cross sensitivity to liver injury with other similar herbal drinks.

Drug Class: Herbal and Dietary Supplements

Other names: Paraguay Tea, Mate Tea, Erva Mate

PRODUCT INFORMATION

REPRESENTATIVE TRADE NAMES

Ilex paraguariensis – Generic

DRUG CLASS

Herbal and Dietary Supplements

Fact Sheet at MedlinePlus, NLM

CHEMICAL FORMULAS AND STRUCTURES

ANNOTATED BIBLIOGRAPHY

References updated: 10 November 2024

Abbreviations: HDS, herbal and dietary supplements.

  • Zimmerman HJ. Unconventional drugs. Miscellaneous drugs and diagnostic chemicals. In, Zimmerman, HJ. Hepatotoxicity: the adverse effects of drugs and other chemicals on the liver. 2nd ed. Philadelphia: Lippincott,1999: pp. 731-4.
    (Expert review of hepatotoxicity published in 1999; several herbal medications are discussed, but not Yerba mate).
  • Liu LU, Schiano TD. Hepatotoxicity of herbal medicines, vitamins and natural hepatotoxins. In, Kaplowitz N, DeLeve LD, eds. Drug-induced liver disease. 2nd ed. New York: Informa Healthcare USA, 2007, pp. 733-54.
    (Review of hepatotoxicity of HDS published in 2007; no mention of Yerba mate).
  • McGee J, Patrick RS, Wood CB, Blumgart LH. A case of veno-occlusive disease of the liver in Britain associated with herbal tea consumption. J Clin Pathol. 1976;29:788-94. [PMC free article: PMC476180] [PubMed: 977780]
    (26 year old woman developed abdominal pain and fatigue having used large amounts of herbal teas [including Yerba mate: “Paraguay tea”] for years and presented with ascites [bilirubin 0.8 mg/dL, ALT 28 U/L, Alk P 303 U/L, prothrombin time 19 sec], biopsy demonstrating veno-occlusive disease [sinusoid obstruction syndrome (SOS)] and subsequently dying of multiorgan failure; testing of the tea revealed contamination with pyrrolizidine alkaloids known to cause SOS).
  • Jacobsson I, Jönsson AK, Gerdén B, Hägg S. Spontaneously reported adverse reactions in association with complementary and alternative medicine substances in Sweden. Pharmacoepidemiol Drug Saf 2009; 18: 1039-47. [PubMed: 19650152]
    (Review of 778 spontaneous reports of adverse reactions to herbals in a Swedish Registry does not list Yerba mate among products associated with 5 or more reports).
  • Teschke R, Wolff A, Frenzel C, Schulze J, Eickhoff A. Herbal hepatotoxicity: a tabular compilation of reported cases. Liver Int 2012; 32: 1543-56. [PubMed: 22928722]
    (A systematic compilation of all publications on the hepatotoxicity of specific herbals identified 185 publications on 60 different herbs, herbal drugs and supplements but does not mention or list Yerba mate or Ilex paraguariensis).
  • Harrold JA, Hughes GM, O'Shiel K, Quinn E, Boyland EJ, Williams NJ, Halford JC. Acute effects of a herb extract formulation and inulin fibre on appetite, energy intake and food choice. Appetite. 2013;62:84-90. [PubMed: 23207186]
    (Among 58 adult overweight women given either 3 tablets of a combination of Yerba mate, guarana, and damiana [YGD], or a soluble fermentable fiber [SFF], or placebo before meals, total food intake was less, but hunger was unchanged with YGD tablets and SFF, and was greatest with the combination, while no adverse events occurred; serum ALT and AST were not measured).
  • Navarro VJ, Barnhart H, Bonkovsky HL, Davern T, Fontana RJ, Grant L, Reddy KR, et al. Liver injury from herbals and dietary supplements in the U.S. Drug-Induced Liver Injury Network. Hepatology 2014; 60: 1399-408. [PMC free article: PMC4293199] [PubMed: 25043597]
    (Among 839 cases of liver injury from drugs collected in the US between 2004 and 2013, 130 were due to HDS products, including 45 from body building agents [probably anabolic steroids] and 85 from diverse HDS products, but no case was attributed specifically to Yerba mate).
  • Kim SY, Oh MR, Kim MG, Chae HJ, Chae SW. Anti-obesity effects of Yerba mate (Ilex paraguariensis): a randomized, double-blind, placebo-controlled clinical trial. BMC Complement Altern Med. 2015;15:338. [PMC free article: PMC4583719] [PubMed: 26408319]
    (Among 30 overweight or obese adults treated with Yerba mate [3 gm daily] or placebo for 12 weeks, there were no differences in changes in body weight, dietary intake, or serum lipids between the two groups, and there were no adverse side effects, routine liver tests did not change and remained normal).
  • Alkhatib A, Atcheson R. Yerba Maté (Ilex paraguariensis) metabolic, satiety, and mood state effects at rest and during prolonged exercise. Nutrients. 2017;9:882. [PMC free article: PMC5579675] [PubMed: 28809814]
    (Among 12 healthy, active adult women ingesting Yerba mate [2 gm] or placebo shortly before a 30 minute cycling exercise in a repeated measures design, fatty acid oxidation and measures of hunger and mental concentration were improved with Yerba mate ingestion; no mention of adverse events).
  • Brown AC. Liver toxicity related to herbs and dietary supplements: Online table of case reports. Part 2 of 5 series. Food Chem Toxicol 2017; 107: 472-501. [PubMed: 27402097]
    (Description of an online compendium of cases of liver toxicity attributed to HDS products lists one case exposed to 12 herbal products including Yerba mate).
  • Medina-Caliz I, Garcia-Cortes M, Gonzalez-Jimenez A, Cabello MR, Robles-Diaz M, Sanabria-Cabrera J, Sanjuan-Jimenez R, et al.; Spanish DILI Registry. Herbal and dietary supplement-induced liver injuries in the Spanish DILI Registry. Clin Gastroenterol Hepatol. 2018;16:1495-1502. [PubMed: 29307848]
    (Among 856 cases of hepatotoxicity enrolled in the Spanish DILI Registry between 1994 and 2016, 32 were attributed to herbal products, the most frequent cause being green tea [n=8] and Herbalife products [n=6], no mention of Yerba mate).
  • Poswal FS, Russell G, Mackonochie M, MacLennan E, Adukwu EC, Rolfe V. Herbal teas and their health benefits: a scoping review. Plant Foods Hum Nutr. 2019;74:266-276. [PubMed: 31243622]
    (Among 21 human studies on the health benefits of herbal teas, only 7 discussed adverse events and only one dealt with Yerba mate; no mention of hepatoxicity of herbal teas).
  • Rodriguez EA, Teixeira Yokoda R, Payton DE, Pai R, Byrne TJ. Acute hepatitis secondary to the use of Ilex paraguariensis (mate tea): a case report and review of literature. Case Reports Hepatol. 2019;2019:8459205. [PMC free article: PMC6815554] [PubMed: 31737383]
    (21 year old American developed jaundice after a 4 month church-mission visit in Argentina during which he drank Yerba mate daily [bilirubin 32.9 mg/dL, ALT 2685 U/L, AST 1842 U/L, and Alk P 129 U/L], a liver biopsy showing an acute hepatitis with cholestasis while viral and autoimmune tests were all negative, resolving spontaneously without therapy over the next 2 months after stopping the herbal beverage).
  • Lutomski P, Goździewska M, Florek-Łuszczki M. Health properties of Yerba Mate. Ann Agric Environ Med. 2020;27:310-313. [PubMed: 32588612]
    (Brief review of the health benefits of Yerba mate including a role in weight loss, prevention of infections, improving serum lipids and cardiovascular health and the stimulatory effects of its caffeine; mentions the possible increased risk for head and neck cancer of long term use, but no mention of liver injury).
  • Gawron-Gzella A, Chanaj-Kaczmarek J, Cielecka-Piontek J. Yerba mate—a long but current history. Nutrients. 2021;13:3706. [PMC free article: PMC8622869] [PubMed: 34835962]
    (Review of the preparation of Yerba mate, its composition, biological activities, clinical effects, and toxicity, mentions the increased risk for head and neck cancer, which has been linked to use to heated Yerba mate).
  • Ballotin VR, Bigarella LG, Brandão ABM, Balbinot RA, Balbinot SS, Soldera J. Herb-induced liver injury: Systematic review and meta-analysis. World J Clin Cases. 2021;9:5490-5513. [PMC free article: PMC8281430] [PubMed: 34307603]
    (Systematic review of the literature on herb induced liver injury identified 446 references describing 936 cases due to 79 different herbal products, the most common being He Shou Wu [91], green tea [90] Herbalife products [64], kava kava [62] and greater celandine [48]; mentions that erva mate, another name for Yerba mate that was implicated in 3 cases, details and references not provided).
  • Bessone F, García-Cortés M, Medina-Caliz I, Hernandez N, Parana R, Mendizabal M, Schinoni MI, et al. Herbal and dietary supplements-induced liver injury in Latin America: experience from the LATINDILI Network. Clin Gastroenterol Hepatol. 2022;20:e548-e563. [PubMed: 33434654]
    (Among 367 cases of hepatotoxicity enrolled in the Latin American DILI Network between 2011 and 2019, 29 [8%] were attributed to herbal products, the most frequent being green tea [n=7], Herbalife products [n=5] and garcinia [n=3], while Yerba mate was not mentioned).