Benefits of Green TeaFebruary 12th, 2016
More than 4,000 years ago, the Chinese uncovered a medicinal yet soothing beverage that has withstood the test of time: green tea.
Fast forward to modern day, and science has caught up with the hype. Studies show that green tea offers so much more than a clean, healthy boost of energy. In fact, it could make a difference with everything from cardiovascular problems to terminal illnesses to bad breath.
Made from camellia sinensis leaves, green tea is one of nature’s most powerful antioxidants. So, if it isn’t yet a part of your daily regimen, then read on: You may want to consider swapping out that morning joe for a morning brew.
Green tea varieties
There are several varieties of green teas, which differ substantially due to growing conditions, horticulture, production processing, and time of harvest.
In China, green is the most well-known type of tea. Chinese green teas are made from more than 600 different varieties of the camellia sinensis plant, and leaves are traditionally pan-fired—dried in thin iron bowls over a furnace. Alternately, leaves might be oven-dried or sun-dried. These different processes give Chinese teas the more “earthy” taste they’re known for.
In Japan, green tea is ubiquitous and commonly referred to as just “tea.” It was originally brought over to the country by Myōan Eisai, the same man who introduced the Rinzai school of Zen Buddhism. Japanese green tea is made from the Yabukita variety of the camellia sinensis plant. The leaves are steamed, giving the tea a more herbal or leafy taste.
Did You Know? Green tea is best enjoyed without extra sweeteners and cream, as they can mask the subtle nuances and potentially negate some of the health benefits.
Sencha, a Japanese tea, is often referred to as “roasted tea” because of the production method. Sencha tea is not roasted until later in the cycle. The leaves are first quickly steamed, rolled, and dried before baking.
This process, particularly the steaming, lends sencha tea an earthy, grassy, mellow flavor that some compare to seaweed.
Bancha tea is a common offshoot of sencha tea. These leaves come from the same plant, but are considered lower-grade.
Sencha is also combined with brown rice to create genmaicha. Also known as “people’s tea,” genmaicha was originally consumed by the poor Japanese who used the brown rice as filler. Today it’s widely popular, and sometimes combined with a small amount of matcha to strengthen the flavor.
Try it: Pique Tea Organic Mint Sencha Green Tea
Gunpowder green tea, a Chinese green tea, is made in the Zhejiang Province and was originally produced during the Tang Dynasty, sometime during the 1st century.
Instead of being ground, the leaves are harvested, steamed, rolled either by hand or by machine into small balls that resemble gunpowder pellets, and then dried again. The rolled leaves last longer because they are less susceptible to absorbing odors and breakage. Gunpowder has the same refreshing, sweet and slightly earthy taste as other green teas, though it also has a hint of chestnut.
Something to note when buying gunpowder tea, generally sold loose in pellet form: If they’re shiny, that’s a sign of freshness. Size will vary, but generally the smaller the pellet, the higher the quality.
Dragonwell green tea
Also called Longjing (after the village it was found in), dragonwell green tea has a storied history. Legend has it, Longjing was home to a fearsome dragon—hence the name “dragonwell.”
The tea itself has some distinct qualities, from its yellow-green color to its shape: broad, flat leaves that take a very long time to dry. The taste is refreshingly smooth, sweet, and delicate with a nutty aroma and a hint of earth—some liken it to chestnut with a buttery finish. Dragonwell consistently rates among the best green teas at tastings.
Try it: Mighty Leaf Organic Green Dragon Tea
Anji green tea
The name anji means “safety and prosperity” in Chinese.
Like all green tea, anji (also called An Ji Bai Cha) comes from camellia sinensis leaves. The best anji leaves are picked in early spring. Because of the way it’s produced, anji is considered a green tea, despite its name. Grown high in the mountains of Zhejiang Province, and picked from the Bai Cha bush, Anji is light apple-green in color with a smooth, rich, and slightly sweet taste. The depth of flavor is often described as “liquid silk,” and because it’s so mellow, fine, and light, it’s also sometimes known as “anji white tea.” And thanks to a high level of amino acids, which help to reduce cortisol, anji is known for producing a calming effect.
Anji tea can be brewed loose or in bags, and is often blended with other flavors like lemon or jasmine.
Matcha differs from the other varieties of green tea in that, rather than leaves, it comes as a fine ground powder. It’s also unique in two aspects of farming and processing: The green tea plants used for matcha are shade-grown for about three weeks before harvest, and the stems and veins are removed during processing.
Matcha—preparing it, serving it, drinking it—also takes center stage at traditional Chinese and Japanese tea ceremonies. These days, matcha is often used to flavor and color foods like mochi, soba noodles, green tea ice cream, and a variety of wagashi (traditional Japanese sweets).
Decaffeinated green tea
Green tea can contain up to 40 milligrams of caffeine per cup—a generic brewed cup of coffee contains between 95-200 milligrams. That’s why, as with coffee, doctors usually recommend pregnant women and those with sensitive stomachs steer clear.) The decaf versions you see on shelves do still have trace amounts of caffeine, only about 2-10 milligrams of caffeine per cup—which is generally safe for pregnancy as long as it’s in addition to other healthy beverages, but consult a doctor first.
Green tea leaves are decaffeinated through a process that usually involves solvents like ethyl acetate or carbon dioxide water, which absorb the caffeine while leaving behind most of the flavor and other nutrients.
The remaining tea is a great solution for those looking for that green tea flavor without the buzz.
The history of green tea
The history of Chinese green tea dates as far back as 2737 B.C. The ancient Chinese appreciated it for its medicinal qualities, but it was so expensive that most people couldn’t partake until the Ming Dynasty (1368–1644 A.D.). Only then, when technology and cultivation methods improved, did green tea become more accessible to the middle classes.
Sailors and seamen helped to spread it across continents. In the early 17th century, a ship of the Dutch East India Company brought the first green tea leaves to Amsterdam from China, according to “The Book of Tea” by Kakuzo Okakura. Soon, it became a symbol of trade between China and the rest of the world, successfully taking root in Japan, the Middle East, and other Asian cultures.
In Japan, green tea gained popularity during the Song Dynasty (960–1279 A.D.), when Buddhist priests spread the word about it throughout the country. At that point, Japan actually started producing its own camellia sinensis plants and different forms of green tea.
Green tea’s antioxidative powers
Green tea is made from camellia sinensis leaves that only undergo minimal oxidation during processing. This keeps the leaves green and helps maintain some of their more powerful antioxidant properties, like EGCG (more on that in a moment). Green tea leaves also contain significant amounts of polyphenols like flavonoids and catechins—both essential in helping the body stabilize free radicals.
You might have heard of free radicals—those unstable molecules that damage healthy cells and may even play a role in causing cancer as a result.
These molecules form in our bodies through:
- Excessive exposure to UV rays
- Eating an unhealthy diet
- Excessive exercise
- Certain medications and/or treatments
Over time, a buildup of free radicals can accelerate aging and raise your risk of developing not only cancer but also other potentially serious diseases. While the body naturally produces antioxidants to prevent these effects, it doesn’t have proper defense to all the things on this list, so supplementary defenses, like those found in green tea, are essential.
The catechins in green tea have other biological effects as well. Some studies show that they can kill bacteria and inhibit viruses like the ones that cause influenza, potentially lowering your risk of infections.
Cancer-fighting properties of green tea
One of the most active catechins in this tea is the antioxidant Epigallocatechin Gallate (EGCG), which has been studied as a treatment for various diseases. In fact, it’s cited as the most significant phytochemical in green tea. After extensive laboratory, animal, and human studies, the benefits of EGCG are just starting to emerge.
EGCG appears to have powerful antioxidant, free radical–fighting effects. One study shows that EGCG has been shown to inhibit tumor growth in a variety of test-tube studies involving cancer of the stomach, lungs, liver, breast, and colon. The compound also actually promotes the death of cancer cells. Ultimately, the authors concluded that EGCG shows promise as a cancer treatment, either alone or combined with other therapies.
Green tea is an excellent source of EGCG and a number of other powerful antioxidants, so drinking it regularly could reduce your risk of cancer. Here’s a quick overview of studies that speak to green tea’s potential cancer-fighting properties.
- Breast cancer: A meta-analysis of observational studies found that women who drank the most green tea had a 22 percent lower risk of developing breast cancer, the most common cancer in women.
- Prostate cancer: One study found that men who drank green tea had a 48 percent lower risk of developing prostate cancer.
- Colorectal cancer: A study of 69,710 Chinese women found that green tea drinkers had a 57 percent lower risk of colorectal cancer.
Multiple studies show that the catechin compounds in green tea can also have various protective effects on neurons in test tubes and animal models, potentially lowering the risk of Alzheimer’s and Parkinson’s.
Green tea can help lower your risk of Alzheimer’s disease
In a Forbes article, “Green Tea May Prevent Alzheimer’s Disease, Say Four New Studies,” journalist Melanie Haiken writes of exciting new research in the fight against the disorder.
“Swiss researchers used functional magnetic resonance imaging (fMRI) to watch the brains of 12 healthy volunteers as they performed tasks testing ‘working memory.’ This type of memory allows the brain to simultaneously store and process information; it’s important to such complex cognitive tasks as language comprehension, learning and reasoning. Participants’ brains were scanned after the subjects had consumed two different doses of a beverage containing green-tea extract, as well as a placebo drink.”
The researchers found that, compared to the placebo group, those who consumed the green tea extract had heightened activity in the dorsolateral prefrontal cortex, which is the part of the brain associated with working memory processing. Higher doses of the extract were shown to proportionally increase activity.
Similarly, a multidisciplinary research team at the University of Michigan discovered that EGCG extract also actually breaks down toxic proteins that accumulates in the brains of those with Alzheimer’s disease.
Green tea may lower your risk of type II diabetes
Type 2 diabetes, the most common, reached epidemic proportions in the past few decades and now afflicts about 300 million people worldwide.
Studies show that green tea can improve insulin sensitivity (which is compromised in people with type 2 diabetes) and also reduce blood sugar levels. One study found that people who drank the most green tea (more than six cups per day) had a 42 percent lower risk of developing type II diabetes.
According to a review of seven studies with a total of 286,701 individuals, green tea drinkers had an 18 percent lower risk of developing type 2 diabetes.
Green tea may help reduce risks of cardiovascular diseases
Cardiovascular diseases, including heart disease and stroke, are the leading causes of death in the world. A 2011 meta-analysis of 14 randomized, placebo-controlled clinical trials found that green tea significantly lowered LDL cholesterol and triglyceride levels.
Additionally, a study of 40,530 Japanese adults found that participants who drank more than five cups of green tea a day had a 26% lower risk of death from heart attack or stroke and a 16% lower risk of death from all causes than people who drank less than one cup of green tea a day.
Green tea wakes you up and improves brain function
Like coffee, green tea contains caffeine. Because it doesn’t have quite as much as coffee, green tea still wakes you up, but is much less likely to give you jitters or trigger a “crash” later on.
However, green tea isn’t just about caffeine, and while it’s known to boost your energy, it can also help you relax. This is because of the amino acid L-theanine, which studies have shown can reduce blood pressure in hypertensive rats. In one study on human volunteers, green tea had a measurable effect on relaxation in certain regions of the brain—without causing drowsiness. This was due to the prevalence of alpha-waves—which are the index of relaxation. L-theanine also increases the activity of the inhibitory neurotransmitter GABA, which has anti-anxiety effects.
Studies show that caffeine and L-theanine can have synergistic effects. The combination of the two is a particularly potent tool for improving brain function, so green tea can give you a much milder and different kind of “buzz” than coffee.
Many people report more stable energy levels and feeling much more productive when they drink green tea instead of coffee.
Green tea has dental health benefits
Suffering from halitosis? One study shows that green tea has properties that can help fight it. Researchers administered green tea, breath mints, chewing gum, and parsley seed oil on subjects’ tongues. Immediately afterwards, green tea reduced the concentration of sulfur compounds in breath more than any of the others.
Additionally, studies show that the catechins in green tea can inhibit the growth of streptococcus mutans, the primary harmful bacteria in the mouth that causes plaque formation, cavities, and tooth decay.
Coffee drinkers, ready to make the switch?
Photo credit: Alicia Cho, Paul Delmont