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.
Detox teas that combine caffeine with diuretics can trigger the loss of water weight. Just two cups of water weighs one pound on a scale, so shedding fluid can make you look and feel lighter–even if you haven't lost an ounce of body fat. Detox teas can also trigger a laxative effect, which causes your body to eliminate waste from your GI tract, another result that can make your stomach flatter, and allow you to feel lighter, even if your lean-to-fat ratio remains exactly the same. If this quick-fix effect gives you the confidence boost and motivation you need to start eating healthier and working out–the real keys to getting healthy and lean–terrific (assuming the teas are even safe to drink–see below). Just remember: If you go back to your former less-than-stellar eating or exercise habits, or stop drinking the tea, you can gain the weight right back just as quick as you dropped it.
Another big draw health benefit-wise is that matcha, like green tea, is loaded with antioxidants. A study, published in 2014, found the plant also had antimicrobial properties, particularly the four types of catechins (antioxidant properties flavonoids) it contains, against a few different types of microorganisms. Yet another study, published in Nature, proved that catechins inhibit the growth of a bacteria called Fusobacterium nucleatum — the bacteria that causes cavities and periodontal disease.
"Tea is a good source of compounds known as catechins and epicatechins, which are thought to be responsible for tea's beneficial health effects," says Dr. Howard Sesso, associate professor of medicine at Harvard Medical School and associate epidemiologist at Brigham and Women's Hospital. These compounds belong to a group of plant chemicals called flavonoids. Research suggests that flavonoids help quell inflammation, and that in turn may reduce plaque buildup inside arteries. Green tea has slightly higher amounts of these chemicals than black tea. Both black and green teas also contain modest amounts of caffeine, ranging from about 20 to 45 milligrams per 8-ounce cup. That's roughly half the amount of caffeine in the same amount of coffee.
Eucalyptus (Eucalyptus Globulus), Ginger (Zingiber Officinale), Anise (Pimpinella Anisum), Tamarind (Tamarindus Indica), Red Raspberry (Rubus Idaeus), Cranberry, Blackberry, Knapweeds (Centaurea), Cornflower(Cyanus), Chamomile (Chamomilla Recutita), Ginseng (Panax Ginseng), Rose Hips (Rosa Canina Fructus), Lemon Grass (Cymbopogon Citratus), Fennel (Foeniculum Vulgare)
While there are some published studies on various ingredients often found in detox teas, I haven't seen any research on the teas themselves, particularly in the precise formulas they're prescribed (that research isn't required for the teas to be sold, by the way). That means that using detox teas leaves unanswered questions about if and how they work, how they should be used, how much may be too much, and possibly who shouldn't use them. If you're unsure, or are planning to start drinking them, talk to your doctor, nutritionist, or health care provider. Just be sure he or she doesn't have a vested interest in the sale of the product you're considering: If they happen to be selling or endorsing it, seek a second opinion.
Matcha tea rich in EGCG helps fight various bacterial, viral, and fungal infections. According to a research study, EGCG binds to the lipid membrane and exerts inhibitory action against the growth of various human pathogens. These include influenza A virus, hepatitis B, and C virus, herpes virus, adenovirus Staphylococcus aureus bacteria, and Candida albicans yeast.
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).