Yerba Maté Summary:
Yerba maté is a popular South American tea made from the Amazonian tree Ilex paraguariensis.
It contains many similar compounds to green tea, including the antioxidant polyphenols and caffeine. Yerba maté also contains theobromine, another stimulating alkaloid related to caffeine. Theobromines actions are only mildly stimulating, and counteract many of the side effects caffeine delivers.
Therefore, because of the more even combination of these 2 chemicals, yerba maté offers the same stimulating actions on as coffee, but brings less of the negative side effects that coffee does, like jitteriness, insomnia, and anxiety.
Yerba maté has been consumed in tea form by indigenous cultures living in the Amazon rainforest for a long time. it has since become very popular in South America, showing up in yerba maté cafes across the continent.
Its benefits include central nervous system stimulation, providing relief from fatigue, improvement in concentration, weight loss support, anti-diabetic actions, and tones the heart.
Much of the work put into The Sunlight Experiment has been fuelled off yerba maté.
There are generally 3 types of yerba maté that you can buy (although each farm has its own take on the processing):
- With Stems
- Without Stems
The stems add a bit of sweetness to this relatively bitter herb, but do not add as much medicinal value as the leaves. With stems is the most traditional method.
Some prefer to receive as much medicinal value from their yerba maté as possible, and do not mind a bit of bitterness. This is why you can find stemless yerba maté.
This is a popular method in Brazil, and offers the most medicinal value, however can be fairly chalky, and bitter. It also usually comes in a form called "Chimarrão".
Syn: Ilex paraguayensis
Leaves and stems
- Appetite suppressant
- Digestive stimulant
- Cardiac stimulant
- Memory enhancer
- Laxitive (mild)
- Cognitive enhancement
- Athletic performance enhancement
- Weight loss support
- Weight gain prevention
- Appetite suppression
- Various digestive complaints
- As a diuretic
- Aid with sleep deprivation
- Topically as an astringent
- Metabolic and endocrine disorders
- As a study or work aid
South American Holly
St. Bartholomews Tea
Traditional use of yerba mate consisted of both chewing the leaves, as well as the commonly known brew (infusion) of its leaves .
Upon “discovery” in the early 1600s by Spanish explorers in Paraguay, it increased in popularity among them. As the demand for this herb increased, the Jesuits started to develop plantations in Paraguay and Brazil to supply it, leading to the common name “Jesuits tea” or “Paraguay tea”. This was due in part by demand for the herb, as well as a lack of mineral wealth and population density in Paraguay, leading the Spanish government to classify yerba mate as a mineral in order to provide economic wealth to the region. This lead to early Yerba harvesters to be referred to as mineros (mine workers). As the Jesuits organized “missions”, they often turned to yerba mate production to support their livelihood. It was generally regarded that yerba mate was hard to cultivate, due to the hard coated seeds necessity to be worn down by the ingestion of birds, before germination was at all possible, it is though that the Jesuits figured this out early on, and kept it a secret from their neighbouring colonies, which gave them an advantage in the region. Other reports suggest that a technique whereby fresh yerba mate berries were plucked and soaked, releasing a thick lather, followed by drying, and planting [3, 16].
The traditional method with which this herb was served, is in a small gourd (mate in spanish) used as a cup, and a small tube with a filter on the end to keep the loose leaves out of the drinker's mouth, called a bombilla. The gourd is filled with 30-60% yerba mate leaves, then hot water is added (sometimes cold), occasionally with flavouring agents such as burnt sugar, lemon juice, and/or milk. The beverage is drunk through the bombilla until no water remains, then the gourd is refilled with hot water, and passed to the next person in the circle until the leaves are exhausted. In this way, yerba mate is drunk socially by groups of people from the same gourd. [3, 16].
In Brazil, this herb has been used to stimulate nervous and muscular systems, for digestive complaints, renal colic, nerve pain, depression, fatigue, and obesity. A poultice has also been employed topically for anthrax skin ulcers .
Some remnants of yerba mate powder that has been found inside Incan tombs, suggest the plant was linked to prestige, however there exists much disagreement on whether yerba mate was much used by indigenous cultures in pre colonial times .
Illex as a genus contains about 300 species, and is classified under the Aquifoliaceae family, which only has 4 genuses. Illex takes up the vast majority of species in this genus .
Yerba mate is a medium sized, slow growing, evergreen tree, growing to a height of 15-20 meters in the wild. When cultivated it is not uncommon for this to be trained into a 4-8 meter shrub instead .
As part of the holly family (Aquifoliaceae), it bears the leathery, stiff, leaves that are common in this family. Leaves are oblong, toothed, and dull-mid color green. Has white flowers, and red fruit .
The species most commonly used medicinally, as well as recreationally, is Illex paraguariensis, and this is the species sold commercially as well. Another species, Illex guayusa is more commonly referred to as Guayusa (pronounced why-yoo-sah), is used traditionally in Ecuador for much the same purposes, however there is much less scientific literature studying this species, and can be difficult to find commercially.
In South America, Yerba mate is considered a national beverage in several countries. In Europe, it is often called “the green gold of the Indios” . Mate bars are very prevalent in South America and can be compared to coffee use in North America and Australia.
It is the leathery leaves that are used medicinally and socially from the yerba mate plant. In South America, not only is this beverage drunk for flavour purposes, but also as a tonic, diuretic, appetite suppressant, depurative, to combat fatigue, and for gastric support.
The wild plant is reported to be unmatched in flavour to cultivated samples.
Habitat, Ecology, Distribution:
Yerba mate is indigenous to the Amazon rainforest, in countries such as Brazil, Paraguay, Argentina, and Uruguay, and is now cultivated in many tropical countries worldwide. Brazil, Paraguay, and Argentina are the leading exporters of this herb, and production still comes from wild stands in some places, but more commonly is cultivated [3, 16].
Harvesting, Collection, Preparation:
To harvest from the wild, Terrafeiros or Yebateros (otherwise called mate gatherers), travel through the jungle searching for a stand of trees (called mancha) to harvest its leaves. This typically takes place between May and October when the leaves are fullest. To preserve the trees for subsequent harvests, the leaves are usually only picked once every 3 years. More commonly however, the plants are cultivated in Paraguay, Uruguay, and Brazil. It takes roughly 4 years before Illex paraguariensis is harvested for the first time, after that, it is harvested every two to 4 years depending on the farmer. The first harvest is usually about 1-2kg, but after a few decades it produces closer to 100 kgs per harvest [3, 16].
The preparation of yerba mate involves many individual processes conducted by different people, yielding many different results in quality, and flavour, in much the same way as tea (Camellia sinensis), and coffee (Coffea arabica). Large scale farms may have mechanized the process, and increased efficiency, but it is usually the farms that take special care in the growing, and preparation of this herb that produces the highest quality, and best flavor. There are many brands, large and small, that sell Yerba mate, and all deliver a unique quality and flavour palate in their product.
Various traditional methods are employed to prepare this tea depending on the producer or tradition. In one method, the branches are cut and held over fire (called sapecado), this process is meant to deactivate the enzymes in the leaves, which in turn makes them brittle, and allows the green color to remain while the plant dries over indirect heat (called secado), then the dried product is coarsely ground (called canchada or mborobire). At this point the herb can be consumed as is, or aged an additional 6 months, then ground more finely (called molida). [3, 16].
Other methods involve par-blanching the leaves in boiling water (also to deactivate the enzymes), then toasted dry in either a pan over fire, or in a brick oven, which will produce a brown colored tea as a finished product.
To consume the beverage, the traditional gourd (mate, usually from a calabash gourd), and bombilla (straw with a filter at the bottom end) are often still employed, however the group “sharing” of the same bombilla is often considered unhygienic by conventional tea drinkers . Yerba mate can also be prepared in the same ways Camellia sinensis or other herbal teas are prepared, in a teapot, french press, or in tea bags. The traditional brewing ratio of yerba mate is quite high (the author suggests about 1:4, or more, equalling about ½ to ⅔ of the gourds volume), with a brew time of a few seconds to a few minutes, as it was commonly drunk in social circles in single doses and passed from person to person, where as other teas like green tea (Camellia sinensis), is often prepared in smaller concentrations (~1:85). Even still, medicinal infusions are brewed for a much longer time (sometimes hours) at a much smaller concentration than green tea (1:20), to extract as much medicinal content as possible. The tannins, and catechins involved with yerba mate, are the constituents associated with the astringent, bitter flavor and are extracted best in long, and hot steeping durations. These are also the constituents associated with possible negative side effects.
The primary active constituents of Yerba mate are xanthine alkaloids such as caffeine, theobromine, and theophylline, as well as saponins (including some novel saponins), chlorogenic acid (10%), caffeic acid, sterols, polyphenols (quercetin, and rutin) as well as containing a rich source of vitamins, minerals, and as much as 15 different amino acids. [4, 16].
Yerba mate has had some claims passed around that it does not contain caffeine, but a different chemical called mateine, which has the same effects but no caffeine side effects, however this is not true. Caffeine is a known constituent of yerba mate through many scientifically validated independent sources, and continues to be confirmed year after year. Caffeine content in Yerba mate is considered to be between 0.7 and 2% with the average being about 1% . In plants, xanthine alkaloids such as caffeine, and theobromine are bound to tannins, sugars, or phenols and are released during the heating process (coffee, cocoa, and yerba mate are all roasted to release these alkaloids). The “mateine” referred to, is likely to be caffeine still bound to the sugar, tannin, or phenol pre-heating.
Compared to other herbs, guarana (Paulinia cupana) is highest in caffeine concentration (4-8%), followed by Camellia sinensis (black tea) (2.5%-4.5%) with yerba mate (0.7%-2%) considered to have slightly higher caffeine content on average than Coffea spp. (1%-2.5%), then cacao seed (Theobroma cacao) (0.25%) with much less .
Pharmacology and Medical Research:
Aqueous extract of yerba mate (Taragui; Argentina), has been shown to produce bactericidal, and inhibitory effects against methicillin-resistant Staphylococcus aureus (MRSA). The antibiotic effects of yerba mate were considered to be due to compounds such as citric acid, caffeic acid, chlorogenic acid, kaempferol, quercetin, quinic acid, and one unidentified compound . Another group of researchers found both the methanolic, and ethanolic extracts of yerba mate active against Staphylococcus aureus, Listeria monocytogenes, and Salmonella Enteritidis, and related the main activity to phenolic compounds, mainly gallic, syringic, caffeic, ferulic and ρ-coumaric acids .
Yerba mate has the ability to “inhibit the formation of advanced glycation end products (AGE), with an effect comparable to that of two pharmaceutical AGE inhibitor drugs”  (page 450). Others report that chlorogenic acid may be involved with these effects on glucose metabolism, and is thought to modulate glucose-6-phosphatase activity .In one study, only the roasted yerba mate leaf produced this action in type 2 diabetic and prediabetic patients .
The saponins have been reported to interfere with cholesterol metabolism, thus relating its anti-cholesterol effects to this group of chemicals in yerba mate . Another study found that both green, and roasted yerba mate infusions lowered LDL, and increased HDL levels in healthy patients, and had a stronger effect on hypercholesterolemic individuals on statin therapy, as well as prediabetic, and type 2 diabetic patients .
Yerba mates anti-inflammatory effects are due to its ability to inhibit lipoxygenase, which is an enzyme involved in the inflammatory process  (page 449). The anti-inflammatory effects noted with yerba mate are resulting from its effect on reducing adipose mass, as well as other constituents contained in yerba mate that may provide anti inflammatory effects to support this action .
Yerba maté was also sohown to exhibit antiinflammatory action through chemopreventive effects in the colon by “suppression of NF-jB signaling pathway via reduction of phosphorylation of IjB-a and GSK-3b”  (page 439).
Yerba mate was shown to have potent antioxidant activity. This same study interestingly found that yerba mate was shown to increase the lifespan of the nematode Caenorhabditis elegans, which is an organism commonly used to test longevity in living organisms. This should not be considered conclusive, but sparks reason to study this action further. These researchers attributed these effects to synergy between the various health promoting effects provided by the constituents of this herb, including its antioxidant effects. .
Yerba mate is able to inhibit lipid peroxidation, particularly LDL, which is considered the initiating factor in atherosclerosis. This, combined with other synergistic actions including antioxidant, cholesterol inhibitory, hypoglycemic, as well as some gene modulatory (paraoxonase-2) activity may prevent the mechanisms involved with atherosclerosis [4, 7, 16].
+ Athletic Support
Ingesting yerba mate before light to moderate exercise, enhances fat metabolism without negatively affecting maximal performance .
Yerba mate leaf extract produced possible chemoprotective effects, through its actions on detoxification, antioxidant effects, and its effects on cellular metabolism. .
+ Central Nervous System Stimulant
Caffeine, which is contained in fairly high concentrations in Yerba mate, is a known stimulant . Theophylline is also a known heart stimulant . All 3 xanthine alkaloids contained in yerba mate (caffeine, theobromine, and theophylline) are indeed stimulating to the CNS, myocardial muscles, and cause peripheral vasoconstriction, and bronchodilation and relaxation of other smooth muscles .
+ Weight Loss Supportive
A study investigating the effects of Illex paraguariensis on mice fed a high fat diet. They stated that “yerba mate extract has potent anti obesity activity in vivo. Additionally, we observed that the treatment had a modulatory effect on the expression of several genes related to obesity”  (pg 2127). It should be noted that the Yerba mate extract referred to in the study was in fact an instant Yerba mate powder at a dose of 1g /kg, prepared daily in water. This study also noted decreased serum levels of cholesterol, triglycerides, LDL, and glucose compared to the control group, which all have shown direct correlation with obesity.
It is likely that through the synergistic actions of the various effects of yerba mate on cholesterol, LDL oxidation, blood glucose, and visceral fat accumulation, rather than one individual action, that body weight is affected positively.
Yerba mates modulatory effect on the expression of several genes related with obesity is also of significant finding , because this may indicate that yerba mate has significant effects on both the treatment of obesity, as well as its prevention.
Interestingly, researchers in one study noted that the effects of early weaning off breast milk is connected to the development of obesity, cardiovascular disease, and insulin resistance later in life . In this study yerba mate's effects on mice exposed to early weaning off breast milk, were investigated. Researches reported that a yerba mate extraction (aqueous) was able to normalize most of the alterations noted in the mice subjected to early weaning. They also suggested that the effects were due in part to hypothalamic mechanisms (the only source so far the author has found that suggests this, though is a significant finding), and showed possible use for other endocrine-metabolic diseases as well.
These effects, strongly suggest the use of yerba mate for weight, and endocrine related disorders, but needs further research, especially to further investigate yerba mates effects on the hypothalamus.
It has been suggested that the intake of Yerba mate correlated with the risk of developing prostate, upper digestive tract, esophagus, stomach, larynx, lung, cervix uteri, bladder, and kidney cancers, however this is highly controversial as a lack of properly conducted, long term studies investigating these effects, as well as strong evidence of the opposite effects being produced .
These effects may be caused by the high tannin content contained in yerba mate, and suggested that by mixing with milk, these tannins were neutralized. She also noted that it would take very high amounts of yerba mate, over long periods of time to develop such a condition. Again, more research is needed.
Care should be taken with individuals sensitive to xanthine alkaloids (such as caffeine), due to this chemicals relatively high presence in this botanical.
There is likely to be synergy between Yerba mate, damiana (Turnera diffusa), and guarana (Paullinia cupana), which was found to prolong gastric emptying (making patients feel fuller for longer), and reduce overall body weight.
Terms and Definitions Associated With Yerba Maté:
Amargo - “Mate Amargo” means yerba mate that has no additives, such as sugar, agave, honey, lemon, milk, etc.
Algarrobo - Common type of wood, aka carob, used to make yerba mate gourds in Argentina.
Bombilla - The filtered straw used to sip yerba mate.
Canchada - Coarsely ground yerba mate.
Cebador - The person who prepares the mate in a mate circle.
Chimarrão - Brazilian term meaning yerba mate prepared in hot water without sugar.
Despalada - Mate without any stems. Synonym is “sin palos”.
Dulce - Mate dulce means sugar has been added to the yerba mate. Sugar is usually added before the hot water is added.
Gaucho - Gaucho mate is yerba mate that is common in Brazil and Uruguay, and uses very strong, often powdery, yerba mate cuts.
Guayusa - Refers to the plant Illex guayusa.
Lavado - spanish for “wash”, used in reference to yerba mate meaning the brew has become watery and needs to be replaced with new leaves. “The mate is lavado”.
Mate - (also called guampa) is the gourd, or vessel used to prepare and drink yerba mate
Mate cocido - Hot coals atop a pile of yerba mate, and sprinkling sugar over the leaves, caramelizing the sugar, before the whole mixture is poured into boiling water.
Matero - Yerba mate enhusiast
Mborobire - Coarsely ground yerba mate.
Mineros - Meaning “mine workers”. This referred to early yerba mate harvesters in Paraguay, due to yerba mate being classified as a mineral during that time for economic reasons.
Molida - Finely ground mate, usually the finished product that is then packaged and shipped around the world for consumption.
Palos - Small white twigs included in some yerba mate to enhance its flavor, providing added sweetness, and adds smooth flavor to the mate.
Palo santo - Bulnesia sarmientoi. This Amazonian wood is often used to make mate gourds, offering its strong, dense, and arromatic qualities. A gourd made of this wood imparts a smoky, pine-like taste to the beverage. Often found in Argentina, Paraguay, and Bolivia. The resin of this wood has healing properties of its own.
Polvo - Meaning powder. This referes to the dust contained in Yerba mate preparations. Many companies will remove this dust, however in a small amount, this polvo will help the mate stick together, and impart added flavo, making the cycle last longer.
Sin Palo - Yerba mate without twigs, some consider the mate is harsher without these twigs.
Tapado - Meaning clogged. This term referes to the bombilla used to drink yerba mate, when it becomes plugged. “El mate este tapado”.
Terrafeiros - Wild yerba mate harvesters.
Terere - (portuguese) Yerba mate that is brewed cold, comes from traditions in Paraguay due to the hot summer months.
Secado - The process where yerba mate is dried over gentle heat, usually takes place after sepecado.
Sapecado - The process of cutting yerba mate branches, and holding them over a fire to halt the oxidation process from occurring, and discoloring the leaves during drying.
Yerba canchada - Refers to the roasted, dried, and coarsely ground Illex paraguariensis “tea” that has not been aged further, or ground finely the way most yerba mate is sold.
Yerbales - Yerba mate orchards
Yebateros - Wild yerba mate harvesters
Yuyos - Herbs and roots used in traditional remedies in Paraguay that are then added to yerba mate. Some examples include peppermint, cilantro, chamomile, etc.
The Sunlight Experiment
Updated: April 2018
Recent Blog Posts:
- Ahmad Alkhatib. (2014). Yerba Maté (Illex Paraguariensis) ingestion augments fat oxidation and energy expenditure during exercise at various submaximal intensities. Nutrition & Metabolism. 11:42.
- Caroline S. Rempe, Kellie P. Burris, Hannah L. Woo, Benjamin Goodrich, Denise Koessler Gosnell, Timothy J. Tschaplinski, C. Neal Stewart, Jr. (2015). Computational Ranking of Yerba Mate Small Molecules Based on Their Predicted Contribution to Antibacterial Activity against Methicillin-Resistant Staphylococcus aureus. PLOS ONE. | DOI:10.1371/journal.pone.0123925 May 8, 2015
- Christine Folch. (2010). Stimulating Consumption: Yerba Mate Myths, Markets, and Meanings from Conquest to Present. Comparative Studies in Society and History. 52(1). 6-36. Retrieved from the web.
- D. P Arcari, W. Bartchewsky, T. W. dos Santos, K. A. Oliveira, A. Funck, J. Pedrazzoli, M. F. F. de Souza, M. J. Saad, D. H. M. Bastos, A. Gambero, P. de O. Carvalho, and M. L. Ribeiro. (2009). Antiobesity Effects, of yerba mate Extract, (Illex paraguariensis) in High-fat Diet-induced Obese Mice. Obesity. 17. 2127-2133.
- Elenise Stucker Fernandes M.Sc, Marcos de Oliveira Machado Ph.D, Aline Minuzzi Becker M.Sc, Fernanda de Andrade M.Sc, Marcelo Maraschin Ph.D, Edson Luiz da Silva Ph.D. (2012). Yerba mate (Ilex paraguariensis) enhances the gene modulation and activity of paraoxonase-2: In vitro and in vivo studies. Nutrition. 28. 1157-1164.
- G. Fisone, A. Borgkvist and A. Usiello. (2004). Caffeine as a psychomotor stimulant: mechanism of action. Cellular and Molecular Life Sciences. Vol. 61. 857-872. DOI 10.1007/s00018-003-3269-3
- José G. Prado Martin*, Ernani Porto, Severino M. de Alencar, Eduardo M. da Glória, Cristina B. Corrêa, and Ingridy S. Ribeiro Cabral. (2013). Antimicrobial activity of yerba mate (Ilex paraguariensis St. Hil.) against food pathogens. Revista Argentina de Microbiologia. 45(2). 93-98.
- Lorenzi, H., & Instituto Plantarum de Estudos da Flora. (2009). Brazilian trees: A guide to the identification and cultivation of Brazilian native trees. Nova Odessa, SP: Instituto Plantarum de Estudos da Flora.
- Maria E. Lima, Ana C. Colpo, Willian G. Salgueiro, Guilherme E. Sardinha, Daiana S. Ávila and Vanderlei Folmer. (2014). Ilex paraguariensis Extract Increases Lifespan and Protects Against the Toxic Effects Caused by Paraquat in Caenorhabditis elegans. Int. J. Environ. Res. Public Health. 11, 10091-10104; doi:10.3390/ijerph111010091
- M. Frant, M. Czajka, and R. Paduch. (2012). Yerba Mate (Illex paraguariensis) effect on human colon normal and tumor cells. IJPSR. vol. 3(12). 4730-4737.
- Natalia da S. Lima, Juliana G. Franco, Nayara Peixoto-Silva, Lıgia A. Mai, Andrea Kaezer, Israel Felzenszwalb, Elaine de Oliveira, Egberto G. de Moura, Patricia Cristina Lisboa. (2014). Ilex paraguariensis (yerba mate) improves endocrine and metabolic disorders in obese rats primed by early weaning. Eur J. Nutr. Vol. 53. 73-82. DOI 10.1007/s00394-013-0500-3
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- Sirima Puangpraphant, Vermont P. Dia, Elvira Gonzalez de Mejia, Guadalupe Garcia, Mark A. Berhow Matthew A. Wallig. (2013).Yerba mate tea and mate saponins prevented azoxymethane-induced inflammation of rat colon through suppression of NF-jB p65ser signaling via IjB-a and GSK-3b reduced phosphorylation. International Union of Biochemistry and Molecular Biology. Volume 39(4). 430-440. DOI: 10.1002/biof.1083
- Taylor, L. (2005). The healing power of rainforest herbs: A guide to understanding and using herbal medicinals. Garden City Park, NY: Square One Publishers