Even organically grown green teas have been shown to contain lead, which is absorbed by the plant from the environment, particularly tea grown in China. When traditional green tea is steeped, about 90% of the lead stays in the leaf, which is discarded. With matcha, since the whole leaf is consumed, you will ingest more lead. One independent group, ConsumerLab.com, which tested teas, estimates that a cup of matcha may contain as much as 30 times more lead than a cup of green tea. Therefore, they recommend drinking no more than one cup daily, and not serving it to children.
Loose leaf green tea has been the most popular form of tea in China since at least the Southern Song dynasty. While Chinese green tea was originally steamed, as it still is in Japan, after the early Ming dynasty it has typically been processed by being pan-fired in a dry wok. Other processes employed in China today include oven-firing, basket-firing, tumble-drying and sun-drying. Green tea is the most widely produced form of tea in China, with 1.42 million tons grown in 2014.
Green tea also seems to boost physical performance, increase exercise endurance, and decrease reaction time, and there are many, many such studies showing these effects from caffeine, although other ingredients in green tea may aid this effect. Caffeine, and green tea’s, ability to mobilize fatty acids in fat tissue to make them more easily available for use as energy also seems to aid physical performance. In one study, caffeine was shown to significantly increase physical performance (exercise endurance and exertion). The antioxidants in green tea may also help prevent tissue damage during physical exertion as well.
The Alzheimer's Society commented that "this study adds to previous research that suggests green tea might help to reduce the risk of Alzheimer's disease. However, the researchers used a far higher dose of the active green tea chemical than would ever be found in the human body. More research is needed to see whether green tea is protective at a much lower dose, and to understand the mechanism involved."
Neither red nor black tea is to be confused with Rooibos, often called “Red Bush Tea” or “Rea Tea” for short. Rooibos (Aspalathus linearis) is a South African plant that is a member of the legume family and is not related to the tea plant (Camellia sinensis). Rooibos has a very different taste and feel than red (or black!) tea, it is much sweeter and lighter than black tea, although it is often mixed with sugar and cream or a lemon as you might find heavy black tea drinking countries such as England or the United States.
So what are the best detox teas to choose? If you’re really focused on a start-and-stop teatox (rather than just incorporating detox teas into your diet), check out programs like SkinnyMe Tea, which offers 14- or 28-day packages of high-quality, loose-leaf herbs to steep. Or save a little cash and try one of these four off-the-shelf detoxifying varieties, recommended by Lagano and Villacorta.
One thing to watch out for in detox teas, though, is a common ingredient—and herbal laxative—senna. “One part of detoxing is the cleansing of the intestines, and senna aids this process,” he explains. While it can be helpful as a night-time drink short-term, taking senna for too long can cause vomiting, diarrhea, electrolyte imbalance, and dehydration. If you feel stopped up, incorporate a senna tea for a few nights (Villacorta recommends Traditional Medicinals Organic Smooth Move). But stick to senna-free varieties for your habitual cup.
Just have a cup of hot green tea after some rigorous exercise and you will be ready for a few more sets in no time. Furthermore, it effectively counters muscular pain due to overexertion of muscles. Although green tea isn’t widely consumed due to the presence of energy drinks in the market, if you visit Japan and China, you will see that green tea is the premier beverage used by practitioners of martial arts and various other sports.
Other Risks: Long-term consumption, in excessive quantities, may give rise to problems such as insomnia, restlessness, annoyance, irritability, headaches, hypertension, abnormal heartbeat, loss of appetite, spasms, constipation, and acute addiction to caffeine. Many times, people who are addicted to caffeine do not feel normal without the substance and suffer from acute constipation, irritation, and lack of concentration in the absence of green tea.
Rooibos is being heavily hyped by producers and distributors as a new health beverage. Unlike true “tea,” it is caffeine-free and low in tannins. It contains minimal amounts of calcium, potassium, iron, zinc, magnesium and much less fluoride than found in real teas. Studies have shown that Rooibos does contain antioxidants and therefore might have some of the health benefits of green tea, but very little research has confirmed this. I found only 17 scientific studies of Rooibos compared to more than 1,000 on green tea. So far, none suggest that Rooibos is the health equivalent of green tea.
Tea culture of Korea was actively suppressed by the Japanese during the Japanese forced occupation period (1910‒1945), and the subsequent Korean War (1950‒1953) made it even harder for the Korean tea tradition to survive. The restoration of the Korean way of tea began in the 1970s, around Dasolsa. Commercial production of green tea in South Korea only began in the 1970s,. By 2012 the industry was producing 20% as much tea as Taiwan and 3.5% as much as Japan. Green tea is not as popular as coffee or other types of Korean teas in modern South Korea. The annual consumption per capita of green tea in South Korea in 2016 was 0.16 kg (0.35 lb), compared to 3.9 kg (8.6 lb) coffee. Recently however, as the coffee market reached saturation point, South Korean tea production doubled during 2010‒2014, as did tea imports during 2009-2015, despite very high tariff rate (513.6% for green tea, compared to 40% for black tea, 8% for processed/roasted coffee, and 2% for raw coffee beans).