Although coffee is the best known and doubtless one of the most popular of the caffeine-containing botanicals, it isn’t the only contributor. Many other plants have caffeine in their compositions, most of which are consumed for both medicinal and recreational reasons in the regions from which they hail. Nowadays in the global village, most are accessible to the curious, the clinical or the epicurean.
Using coffee as our baseline for caffeination power and effects, let’s assess the other herbal stimulants that contain the alkaloid along with their unique properties when they differ from those of the dark brown brew. (And in case you didn’t catch the post on coffee and its make-up, you’ll find that here.)
Second only to coffee, our first contestant is the cup of tea (camellia sinensis & spp.). Tea is actually the world’s most consumed beverage after water – contrary to what the cola and coffee habits of the Americas would lead us to believe1. Issuing from China a couple of thousands of years BC, it has since made its way around the Earth along the routes of the spice trade landing in Europe in the 16th century and then through to the American continent2.
While tea has more caffeine by weight than coffee, less is used per cup therefore the dilution rate results in a far weaker level of kick as compared to coffee. Whereas your average 8 oz cup of coffee carries a 95-200mg punch of caffeine, the same amount of tea will provide 14-70mg depending on the type of tea and the length of infusion8.
In addition to the caffeine that tea shares with coffee, it also has a significant amount of flavanols and flavonols (oxidized and present as theaflavins and thearubigins in black tea6,7, 25) by weight6. In plain English, flavanals, flavonols and their oxidized counterparts are the highly hyped ‘’anti-oxidants’’ of health literature. The theaflavins are also responsible to a large extent for the flavour and astringency of the tea while the thearubigins provide its colour6, 7. These are analogous to coffee’s chlorogenic acid (CGA), acting in much the same way6, 7.
Along with its lightly uplifting effects, preliminary research suggests that the consumption of black and green tea may help lower cholesterol levels and blood pressure, although much more research is necessary in order to confirm this3. Although green tea or its extract is marketed as an aid to weight loss, scientific studies don’t confirm the validity of the claim4. Tea, the green variety specifically, is also currently unproven but under study as a means of cancer prevention, with empirical evidence on the subject being conflicting in nature at this point5,6. Finally, if you don’t mind the staining from its consumption, some research suggests that tea benefits oral health in a variety of ways including through cavity reduction and by combating acid erosion of the enamel9.
For those that do want to give tea a whirl for its possible benefits but find the tannins upsetting to the stomach, mixing green tea powder into a fruit smoothie can be a better tolerated alternative. This is particularly true when the blended drink contains banana which is particularly soothing to the gut.
Next, there’s mate or yerba maté (Ilex paraguariensis), an infused beverage from South America6, 10 which is slowly gaining ground outside its native land10. Traditionally the drink is prepared in a hollowed out gourd known as a mate or guampa and the liquid consumed through a straw with a filter on the submerged end, a bombilla, to keep the plant matter out6, 10. The same herb is used for multiple fillings of the guampa and consumption is usually a social activity10.
Here again we have the same combination of caffeine and polyphenols that characterize tea and coffee. The polyphenols in question are chlorogenic acid (CGA) which is also found in coffee, along with feruloylquinic acid, kaempferol, rutin, quinic acid, and a host of others6, 10, 11, 12. As already stated above, these are the ‘’free-radical scavenging antioxidiants’’ which make such a splash in health media.
Maté also contains saponins that are responsible for its distinctive taste. These saponins may have anti-parasitic, anti-inflammatory and cholesterol lowering benefits, although further research is required to ascertain this with any certainty10. It also contains trace amounts several vitamins and minerals but not in levels of any dietary significance, with the exception of manganese, for which the bioavailability needs to be studied further10, 14. Like many of the other caffeine-containing herbs, it is being assessed as an aid for weight loss but has yet to demonstrate an irrefutable potential in this direction – although it does seem to affect several aspects of metabolism (as does caffeine generally)10.
There is still a degree of controversy as to the increased likelihood of oral and oesophageal cancers (including those of the larynx and pharynx) in those who drink maté, with some convincing science on both sides of the argument6, 10, 15, 16,,17. Currently, the verdict is still out, but paradoxically more and more information is surfacing on maté’s anti-cancer potential18 – go figure.
Cup for cup when it comes to caffeine-kick, maté and coffee are pretty similar10. Consumed in the traditional manner with multiple fillings of the gourd however, a mate-sit-down amongst friends can often result in a greater volume of beverage being taken in and thus a larger amount of caffeine consumed per unit time10, 13. While some of the popular tea-bagged matés out there advertise that they are a lower-caffeine alternative, roughly a third of the strength of coffee, that’s because they’re only using about a third of the amount of maté usually used in their calculated serving. This strategy makes the brew less distinctive and more herbal-tea-like in its flavour, a benefit when trying to market a new taste to an uninitiated clientele.
Moving along we come to cacao (Theobroma cacao), an interesting and well-loved member of the materia medica with a complex flavour and history. The plant’s name, Theobroma, literally means “food of the gods”19, 22; an assessment most chocolate lovers would agree with. Native to the South American continent, evidence of the use of cacao for ceremonial, medicinal and culinary purposes has been found in archaeological sites spanning back almost 4000 years19, 22, 26. Economically it was used as currency by the Aztec empire20, 21, 22 and through to modern times in some of the smaller areas of Latin America20.
The amount of caffeine in cacao-containing products varies considerably, from as little as 12mg in a 100g bar of milk chocolate to 160mg per 100g in some dark chocolate samples33. But 100g is a lot of chocolate, and generally speaking the amount of caffeine consumed when indulging in a cup of cocoa or a square of melt-in-your-mouth goodness is inferior to what’s found in an average cup of joe33. Putting that aside let’s look instead at the other constituents such as theobromine & theophylline24 and a host of polyphenols25 (cacao flavanols – CF25, 26) which make cacao unique.
Theobromine (3,7 – dimethylxanthine)28 is a purine alkaloid like caffeine (1,3,7 – trimethylxanthine)27, but with somewhat differing effects25, 26. It is highly fat soluble and while it possesses only about a fifth of the stimulant effect of caffeine, it takes longer to eliminate from the body giving it greater staying power in the system26, 30. The substance in isolation from caffeine has been studied to only a limited extent, despite being the most important methylxanthine constituent of cacao. As a result its overall affect as compared to caffeine is currently difficult to ascertain other than at a hypothetical level26 although consumers are aware of a difference between the two30.
Theophylline (1,3 – dimethylxanthine) is a methylxanthine too, with similar but distinct effects to its cousins theobromine and caffeine. The isolated compound is often administered in allopathic care for the treatment of chronic obstructive pulmonary disease and asthma where it improves lung function and levels of oxygen and carbon dioxide in the blood29.
When it comes to the polyphenols, like the others covered thus far, cacao flavanols (CF) possess anti-oxidant and anti-inflammatory properties according to the growing body of research on the subject30. They also seem to favourably affect intestinal flora, essentially acting as prebiotics, increasing the amount of beneficial bacteria and reducing more harmful players30, 31. Chocolate, while made from cacao, is usually not as rich a source of flavanols since the food product is a combination of ingredients usually including large amounts of fat and sugar along with additives to improve texture and longevity of the finished confection26.
Meta-analysis of the studies done on the effect of cacao on blood pressure seem to point toward a small reduction, of the order of 2-3mm Hg, in most test subjects as a result of the flavanols the substance contains23. The assessment does however specify that “longer term trials are needed to elucidate whether regular consumption of flavanol-rich cocoa products has a beneficial effect on blood pressure and cardiovascular health over time, and whether there are any potential adverse effects of long-term ingestion of cocoa products on a daily basis.23”
As an added bonus, besides the fine flavour and anecdotal use as an aphrodisiac, for many people cacao doesn’t seem to disturb sleep patterns in the way that coffee can, the theobromine offsetting caffeine’s action in that respect30, 32. It’s also one of the only caffeinated botanicals that supplies a significant fat content in the form of cacao butter (probably since its most important methylxanthine component is fat soluble…); and in both culinary and cosmetic applications, it’s truly decadent.
Overall in addition to the boosting, bronchodilating and cardiovascular effects of their methylxanthines, all of the herbs visited contain dietary polyphenols. I am therefore concluding with a caution:
When reading wild claims on any of the polyphenol containing herbal substances it is good to keep in mind that behind the hype, although they demonstrate some stunning in vitro effects, in vivo many of these qualities are mitigated by the bioavailability of the substances and co-factors affecting their metabolism25. While some of the results appear to be statistically significant and there is definitely strong potential for human benefit, much more study is needed to ascertain what works, how it works and under what conditions25. In short – while one can include reasonable amounts of any of the caffeine-containing herbs we’ve looked at above in the diet – it’s wise to remain wary of snake-oil salesmen promoting concentrated extract products with amazing results: if it sounds too good to be true, it most probably is.
The next installment on Herbal Stimulants Containing Caffeine (because this installment already has way too long a reference list) will cover the herbs to be used with discernment and discretion – the powerhouses of caffeination for extremely occasional use such as guarana and kola.
1 – Alan Macfarlane; Iris Macfarlane (2004). The Empire of Tea. The Overlook Press, p. 32.
3 – Hartley L, Flowers N, Holmes J, Clarke A, Stranges S, Hooper L, Rees K. Green and black tea for the primary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD009934. DOI: 10.1002/14651858.CD009934.pub2
4 – Jurgens TM, Whelan AM, Killian L, Doucette S, Kirk S, Foy E. Green tea for weight loss and weight maintenance in overweight or obese adults. Cochrane Database of Systematic Reviews 2012, Issue 12. Art. No.: CD008650. DOI: 10.1002/14651858.CD008650.pub2
5 – Boehm K, Borrelli F, Ernst E, Habacher G, Hung SK, Milazzo S, Horneber M. Green tea (Camellia sinensis) for the prevention of cancer. Cochrane Database of Systematic Reviews 2009, Issue 3. Art. No.: CD005004. DOI: 10.1002/14651858.CD005004.pub2
6 – WHO IARC Monographs on the Evaluation of Carcinogenic Risks to Humans (1991): Coffee, Tea, Mate, Methylxanthines and Methylglyoxal. Vol 51: monographs.iarc.fr/ENG/Monographs/vol51/mono51-8B.pdf
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9 – The Way of Ayurvedic Herbs, by Karta Purkh Singh Khalsa and Michael Tierra, Lotus Press, 2008; 107-108.
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