All across the world, people seem to have acquired a similar habit: they almost all drink some kind of beverage made from a bitter plant.
The beverage can be hot or cold; additional ingredients can be added to offset the bitter taste (for example, milk and sugar).
Coffee, tea, and cocoa are the three main examples—but there are many others! The drink contains a stimulant (usually caffeine) as well as many chemicals that act as health benefits.
The oldest of these is tea.
All types of tea trace their roots back to China, probably back to the Shang Dynasty (which began in 1600 B.C.). The tea plant, Camellia sinensis, is an evergreen shrub or tree that has spread all over the world.
There are two varieties of the tea plants, Camellia sinensis var. sinensis, the Chinese variety, and the Camellia sinensis var. assamica, the Indian type.
(The main difference is that the Chinese variety has smaller leaves than the Indian one)
The tea plant, regardless of variety, is used to make all the major classifications of tea, that is, white, yellow, green, oolong, black, and pu-erh.
Each variety has a number of sub-varieties that have been hand-bred for certain traits, known as cultivars—i.e., cultured varieties. The different cultivars are often specialized to be especially good at producing high-quality teas of a specific classification.
For example, the Biyun cultivar in China and the Yabukita cultivar in Japan are both bred to make especially good green tea.
The main countries that grow tea are China, India, Kenya, Sri Lanka, Turkey, Indonesia, Vietnam, Japan, Iran, and Argentina—making it a truly worldwide drink.
The spread of tea outside of China began in the 1820s, when the British East India Company decided to try to break the monopoly of Chinese tea, and offered free land and tea seeds in the Assam area of northern India to anyone who would grow it. (Who this “free land” came from isn’t generally mentioned.)
Modern worldwide tea production tops 5.3 million metric tons (5.8 million U.S. tons) per year.
Why green tea? And what kind of green tea is good for you?
For many years, the Western world market for tea has been dominated by black teas. It’s only recently that we’ve been exposed to green teas—however, throughout Asia, green tea is the most commonly drunk.
The main differences between green and black teas are twofold: “caffeine levels” and “flavors”.
There may also be different health benefits between black and green teas; however, both black and green teas mainly share the same potential benefits.
Green tea leaves are picked, allowed to wither a bit (sometimes in the sun), “fixed,” and then dried. (“Fixing” a leaf means heating it in order to stop it from turning black—tea leaves, like apples, turn dark brown when bruised.)
The gentle treatment of the leaves makes for a more delicate flavor.
There are two main types of green tea flavors that depend on how the leaves are “fixed.”
- The first main “fixing” process is to steam the leaves. This raises the temperature of the leaves quickly, which keeps the color of the leaves a bright green and the flavor of the leaves very grassy (normally known as Japanese Green Tea—Steamed).
- The second process is to pan-fry the leaves by putting them in a large pan over low heat, stirring constantly. This process turns the leaves slightly yellowish as different flavor compounds develop (normally known as Chinese Green Tea—Pan Fired).
Black teas generally have higher levels of caffeine, 42 to 72 milligrams per eight-ounce cup, while green teas have between 9 and 50 milligrams (other classifications of tea have other levels of caffeine as well).
(A cup of coffee has approximately 95 milligrams of caffeine, for comparison. The British and Irish often take advantage of the variation in caffeine levels by making “breakfast” teas with higher caffeine levels, and midday teas with lower ones.)
The different flavors of teas are mainly the product of how the tea leaves are processed, although the cultivars and growing methods of the tea also make a big difference.
Roughly speaking, black tea leaves are picked, allowed to wither, rolled or bruised in order to darken the leaves even more (a process called oxidation), and then dried.
They are not “fixed.” This brings out more bitter flavors in the tea leaves.
Black tea leaves are not “fermented,” as the process is commonly described, but oxidized. There is a type of tea that is fermented; it is known as pu-erh.
A green tea that has been pan-fried has a more complex flavor than a green, grassy steamed tea—for example, the pan-fried Dragonwell tea versus the steamed Sencha tea.
A panfried tea leaf will almost always be very flat in appearance. Matcha tea, the bright green Japanese tea used in Japanese tea ceremonies, is steamed, then ground into a powder.
If you want a bright, cheerful, green tea, then the grassy, steamed varieties are very nice. If you want something more subtle and complex (almost like a fine wine), then pan-fried varieties can be wonderful.
If possible, take a look at the leaves themselves before purchase—yellowish, flat leaves are pan-fried; wrinkled, green leaves (or green powder) are steamed.
There are a few varieties of green leaves that are roasted after they are fixed; they are usually very mellow and subtle, with hints of caramel, and include hojicha.
Another interesting type is genmaicha, a steamed green tea with roasted rice, containing both bright and mellow elements.
Health benefits of Green Tea
The health benefits of tea requires a lot more study. While there have been a number of studies supporting a wide range of benefits, many of the studies haven’t been replicated or have other issues.
For example, some of the studies have as yet only been performed in vitro (in carefully controlled test conditions, such as a test tube) but not yet in vivo (on live participants).
What is known for certain so far in multiple studies and meta-analyses over multiple studies is that drinking tea has a strong benefit with regards to:
- Reducing total cholesterol and the “bad” low-density lipoprotein (LDL) cholesterol.
- Relaxing the blood vessels, which can lower high blood pressure. (However, adding milk negates this effect.)
Other possibilities have not yet been provided a great deal of evidence in studies, but are very exciting in the studies that have been completed. Tea, especially green tea:
- May help prevent some types of cancer,
- May help in some types of cognitive decline due to age, and
- May help people maintain a healthy body weight.
What makes tea so interesting are the polyphenols that it contains.
Polyphenols are a type of organic structure that are mainly found in plants; some types of dried leaves are over 50% polyphenols by weight. Polyphenols are the source of most antioxidants.
The antioxidant specific to green tea includes Epigallocatechin Gallate (EGCG), which may support:
- Brain health, by supporting neuron generation in the hippocampus, the part of the brain most affected by Alzheimer’s and Parkinson’s diseases,
- Weight loss, by raising metabolism and body heat,
- Heart health, by providing many benefits to the cardiovascular system,
- Cancer prevention, by serving as an antioxidant against free radicals in the body.
However, more testing needs to be done before we can be sure of the effects (or the best dosages and methods of treatment).
Another amazing part of green tea is its calming effect (despite the drinking having a certain amount of caffeine in it).
This is due to L-theanine, an amino acid (protein) found almost exclusively in tea plants.
It’s what gives tea its “yumminess,” or umami flavor. L-theanine also:
- Increases serotonin and dopamine levels in the brain, which reduces anxiety and depression.
- Increases the GABA inhibitory transmitter, which blocks some of the effects of the caffeine in tea as well as inhibits other types of nervous excitability.
So, green tea not only has long-term health benefits, it can put you in a better, calmer, more clear-headed mood.
Traditional Chinese medicine also named as tea in general, and green tea especially as beneficial. Some of the properties that have been found in traditional Chinese medicine include:
- Anti-toxic (there are legends about Chinese gods who would try various plants to discover their properties, then eat tea leaves to cure any poisonous effects—not recommended!),
- Expectorant (producing sputum)
- Stomachic (easing stomachaches)
- A nerve sedative
- Relieving headaches
- Carminative (reducing flatulence)
- And more.
And regardless of what the results of future studies about green tea may show, overall the health benefits of green tea far outweigh the risks—as proved by thousands of years of practical testing as people continue to drink tea.
Let’s talk about a few side effects
However, as with anything beneficial, a lot depends on the dosage. Tea can also have a few negative side effects, mainly related to drinking a great deal of tea or taking concentrated supplements.
Green tea should never be taken by anyone taking some types of chemotherapy medications, as it can interfere with how well those drugs work.
Green tea also contains oxalic acid, the same chemical that makes rhubarb leaves bad to eat; for most people, this isn’t a problem, because the amount of leaves used in tea throughout the day is so small (relative to, say, a rhubarb salad!).
However, people who have to avoid oxalates should avoid tea leaves in general, and massive over-consumption of tea can cause kidney failure.
Because of high levels of pollution (and low levels of regulation) in tea-producing areas, some teas may contain trace amounts of aluminum or lead—but again, this is another area requiring more research.
Tea may inhibit the absorption of iron—a concern for people with anemia.
Tea leaves do contain fluoride, however; if you’re drinking economy tea (using older, more fluoride-rich leaves), then it may be best to limit tea-drinking to under a liter (or about four and a quarter cups) per day.
How to prepare green tea?
The methods of preparing green tea are varied according to the type of tea and the type of culture in which that tea is usually drunk.
The simplest, easiest method is
- Take about one teaspoon of green tea per eight-ounce cup of water. The water should be at about 180° F or 80° C, just under boiling temperature (you can bring water to a boil and let it cool slightly).
- Put the tea in a tea strainer of some sort (if you’re using loose-leaf tea).
- Add hot water to a cup and place the tea strainer in the cup so that it freely soaks the tea leaves in the hot water.
- Wait two or three minutes, then take the tea out.
The hot water will extract the polyphenols, which in green tea leaves remain a yellow-green or bright green color (depending on whether they were pan-fried or steamed).
The tea should be yellowish to bright green in color, not pale and watery.
If you let the tea leaves stand for too long, the bitter polyphenols will overpower the taste of the tea. Some of the polyphenols in tea are tannins, and can give an over-brewed tea a wooden, oaky, astringent flavor if left in the tea for too long.
The good news is that you can re-brew high-quality green tea. The tea that comes in a teabag is generally too low-quality and in too small an amount to be worth rebrewing, but many loose-leaf green teas are excellent when rebrewed.
There are two ways to do this.
- If drinking tea by the cup, raise the temperature of the hot water used during subsequent brewings (by 5° F or 3° C), and reduce the amount of water in the cup a little. The flavor will often be more subtle; in the case of strongly-flavored teas, sometimes the perfect cup is the second one.
- If drinking tea by the pot, just keep refilling the teapot with hot water until the tea is too weak to bother drinking. You may want to allow the tea to brew slightly longer than the first brew if using a teapot.
You can add a teaspoon of honey, some fresh lemon juice, even a slice of fresh ginger (put the ginger in with the tea leaves and take it out at the same time).
If you have fresh fruit on hand, muddle it (crush it with a bar muddler or the back of a spoon) in the bottom of your tea strainer or teacup, and remove it when you remove the tea leaves.
Mint, vanilla, basil, orange or lemon peel, fennel, anise—the possibilities are wide open.
If you want to make a slightly fancier pot of tea, then bring your water to a boil, cool it to the appropriate temperature, pour some hot water into the empty teapot and pour it back out again (in order to heat the pot), then add the tea leaves as before—one teaspoon per eight-ounce cup. Add the water, wait two to three minutes, and pour the tea into the cups.
To ensure the tea is the same strength for all cups, poor a little bit into each cup, then fill the rest of the way to the brim.
If you want to experience tea at its fanciest, check out your local botanic garden, Japanese garden, or tea shop for tea ceremonies in the area.
Botanic gardens sometimes have a tea house (chashitsu) and will often hold demonstration tea ceremonies. You may need to schedule ahead of time to reserve a place.
You can also order a British-style afternoon tea with finger foods, cakes, and other refinements and order many different types of green tea. Again, research the location ahead of time and make sure to make reservations as necessary.
How much green tea to drink?
How much green tea to drink will depend on several factors:
- the quality of tea;
- what varietals of tea are being drunk;
- how well the tea is prepared?
However, if the tea is prepared using the directions above, about 2 to 3 cups per day is ideal. If you’re going to drink more than that, make sure to use high-quality tea rather than economy tea.
Please check with your doctor before drinking large quantities of tea or taking tea supplements, especially if you’re pregnant, are on other medications, or have a significant health problem like diabetes, anemia, anxiety, heart issues, bleeding disorders, irritable bowel syndrome, high blood pressure, glaucoma, or osteoporosis.
Green tea is so delicious and good for you that it’s tempting to take it to extremes—if something is good, then wouldn’t more of it be better?—but what is good for you in reasonable amounts can overwhelm your body quickly if taken in too-large amounts.
Please drink tea responsibly!