According to Chinese legend tea (Camellia sinensis) was discovered accidentally by the illustrious progenitor of agriculture Shen-nong when some leaves from the plant dropped into a pot of water he was boiling. Shen-nong was so taken with the flavor and benefits of this herb that he introduced the beverage to humanity, and as the legend goes, the Chinese have been drinking tea ever since. Spreading from China over the Silk Road into the Middle East, tea was brought to Europe by Dutch traders and then later the British introduced it to India. Poems have been sung about and wars have been fought over tea: it is a potent symbol of both sophistication and wealth, and in some cases revolution, appreciated not just for its unique flavor but for the benefits noted by Shen-nong millennia before.
In physiological terms tea is a sympathomimetic, ‘mimicking’ or stimulating the ‘fight or flight’ or sympathetic nervous response. The active ingredient in tea is caffeine, complemented by smaller amounts of other methylxanthine alkaloids such as theobromine and theophylline. Collectively these alkaloids comprise upwards of 9% of the dry weight of tea, but due to the lower solubility of the mouth-puckering bitter tannins tea is rarely prepared as a strong beverage. As a result tea has an average caffeine content of about 40 mg, with much less for watery white or green tea, and upwards of 90 mg for dark black tea. Although generally thought of as a stimulant, tea also contains a neuroactive amino acid called theanine (1.3%) that inhibits sympathetic activity, rounding out and balancing the stimulatory effect of tea.
Apart from its effects on the nervous system, tea also contains an array of antioxidants including flavonoids such as the catechins, kaempferol, quercetin, and myricetin. The catechin epigallocatechin gallate (EGCG) as well as other green tea catechins have attracted a lot of interest from medical researchers, showing promise in the prevention and treatment of cancer. Epidemiological research has show that the regular consumption of green tea in particular is associated with a decreased risk of cardiovascular disease, and in general, promotes a longer, disease-free life. Despite the health benefits of tea however, its regular consumption is not without some risk. Tea naturally accumulates potentially toxic amounts of both fluoride and aluminum from the soil, and is particularly concentrated in compressed (‘brick’) tea, oolong and black tea, with lesser amounts in both pu-erh and green tea.
There are several different types of tea, including white tea, green tea, oolong tea, black (red) tea and pu-erh tea. White tea is gathered from young and/or shade-grown leaves, wilted indoors and then baked to prevent oxidation. It has a mild flavor and a harmonious action in the body. Green tea is grown and dried in the open sunlight and then baked to preserve the green color of the leaves. It has a cooling effect, and is a good accompaniment to spicy foods or in symptoms of excess heat. In Japan the cooling effects of green tea are often balanced with roasted rice (genmai cha) that has a warming, nourishing property. Pu-erh tea is a type of green tea that has been allowed to ferment like grass clippings, which provides for a brown color and an earthy flavor, and is regarded as balancing and good for health. Oolong tea is allowed to oxidize awhile before it is heat-dried, and is considered to be more warming in energy than green tea, and is useful to hydrate the body. Oolong teas are sometimes blended with other flowers like jasmine, gardenia, magnolia, honeysuckle or rose to impart different flavors and effects. Red tea (“black” tea) is a completely oxidized tea with a dark red brown color, and has stronger, stimulatory effects, often used in winter to generate more activity and heat. Bancha or ‘twig’ tea prepared from the dried stems has a harmonious action with little of the stimulatory effects of the leaf.
From the perspective of Ayurveda, the light and dry qualities of tea balance pitta and kapha, but can easily aggravate vata. Tea is widely consumed in India as chai, prepared from black tea often cooked down into a dark black extract that is mixed with spiced milk and sugar. Despite its popularity tea is an entirely new food to the Indian subcontinent, and is considered to be a kind of vice by religious or spiritually minded people. Most of the tea drunk outside of China is black tea, and due to its bitter and astringent flavor is usually mixed with lots of sugar, contributing to the worldwide epidemic of diabetes. In India chai is often taken with several teaspoons of sugar, whereas in the Middle East black tea is sucked through a sugar cube or a chunk of rock sugar. Similarly, black tea is often consumed with sugar in the West, with milk or cream when taken warm, or as a sweetened iced tea. While sweet tea should be avoided due to its deleterious effect on blood sugar, adding a protein-rich condiment such as milk or cream helps to neutralize the tannins that can bind to and precipitate proteins in the gut wall.
Chocolate (Theobroma cacao) is an ancient food considered sacred by the Olmec and subsequent Mesoamerican peoples, with evidence of its cultivation as far back as 1100 BCE. Known by the later Aztecs as xocolatl, chocolate was an important economic and spiritual plant in Mesoamerican culture, reflected in its genus name Theobroma (‘theo’ – god, ‘broma’ – food). Chocolate was prepared by fermenting and roasting the seeds of the cacao pod, grinding them into a powder, and then beating this with water to create a bitter-tasting frothy drink. Compared to tea chocolate contains much less caffeine (1.29%), but augments this with a higher theobromine content (3.35%), and given that chocolate is consumed rather than brewed as a tea, the stimulatory effects can be significant. This effect is complimented with psychoactive, mood-altering compounds in chocolate including anandamide, phenylethylamine and tetrahydro-beta-carboline alkaloids that may explain the common use of chocolate to boost mood and treat depression. Chocolate also contains polyphenols that have potent antioxidant and antiinflammatory properties that support cardiovascular health, and may be helpful to prevent diseases characterized by endothelial dysfunction including hypertension, diabetes, dementia and pre-eclampsia.
Chocolate is not an indigenous food to India, and hence the traditional literature of Ayurveda is silent on its properties and benefits. Given its almost ubiquitous usage as a panacea among Mesoamerican peoples however it is fair to suggest that chocolate is a health food, but only when used in its in traditional context. This means that most of the chocolate in the marketplace, which contains an average of 15% cocoa as well as numerous additives and preservatives, is a rather poor substitute for this ‘food of the gods’. As a confectionery item the highest percentage of dark chocolate is a better choice, but can still contain very high amounts of sugar. Cocoa powder is also used as a savory ingredient in traditional Mexican sauces called moles, added in at the end of cooking. Raw cacao nibs are marketed as a source of antioxidant-rich polyphenols, but this ignores thousands of years of tradition that employs both fermentation and roasting to deactivate anti-nutrient factors in cacao.
Among the three prominent sources of methylxanthine alkaloids in our diet, coffee is the newcomer on the block. As one legend goes coffee like tea was discovered accidentally, this time by a humble Ethiopian goat-herder rather than a celestial emperor. Another story is that it was discovered by a holy man named Sheikh Omar while he was exiled in the desert, later becoming a drink used by the Sufis, a sect of Islam that seeks to manifest a state of ecstatic transcendence through meditation, singing, chanting and dancing. With Sufi monasteries becoming the first coffee houses, the beverage spread across the Middle East and by the 1600’s made its appearance in Europe. Since then coffee has overtaken tea as the world’s most popular beverage, doubling tea production to over 6.6 million metric tons annually.
Coffee only contains about 3.2% caffeine and very little theobromine or theophylline. Despite this the solubility of caffeine in coffee is higher than tea, not least because it is ground into a fine powder before preparation to increase the surface area and enhance extraction. The average caffeine content of coffee is about 100 mg per cup, more or less depending on the method of preparation. Espresso has lower caffeine content of between 58-75 mg per shot, whereas brewed coffee may contain over 250 mg per cup. As an essential method to bring out the different flavors of coffee, roasting also decreases caffeine content in coffee beans, with darker roasts such as French or Italian having less caffeine than medium roasts such as City or American.
Like tea and chocolate, coffee is another relative unknown in traditional Ayurveda, smuggled back from Arabia and planted in near Mysore, India by a Sufi named Baba Budan in the 17th century. According to the Arab physician Al Razi, coffee is hot and dry in quality, and has a stimulatory effect on the stomach. From an Ayurvedic perspective coffee is warm, light and dry in property and is helpful to balance kapha. It promotes stomach emptying and stimulates bile excretion, inhibiting appetite and promoting intestinal movement. It is generally avoided in both pitta and vata, and should only be consumed after a meal, and never first thing in the morning. As a general rule of thumb coffee should be limited to 1-2 cups per day, as any more creates dependency and actively promotes other health issues including stress, gum recession, headache, bowel problems, arthritis, and back pain.
Maté or Yerba maté (Ilex paraguariensis) is another caffeine containing beverage from South America. Like cacao it has a long history of use among indigenous peoples and has become an increasingly popular substitute for coffee and tea in the West. Although sometimes marketed as “caffeine-free”, maté contains about 2% caffeine and 0.5% theobromine.