Studies on green tea’s impact on cancer have been mixed. But green tea is known to aid healthy cells in all stages of growth. There are some clues that green tea may help destroy cancer cells, but that research is still in its early stages, so you shouldn’t count on green tea to prevent cancer. In fact, the National Cancer Institute's web site says it "does not recommend for or against the use of tea to reduce the risk of any type of cancer."
One study that was published in the February 2010 issue of the Journal of Agricultural and Food Chemistry investigated the effects of catechins on eye diseases and found that consuming more catechins may help protect the eyes from oxidative damage and vision loss. Scientists involved in the study found evidence that catechins can pass from the digestive tract of rodents to the tissues of their eyes and reduce oxidative stress for up to 20 hours after ingestion. (11)
Matcha is a high-grade green tea ground into powdered form. The green tea powder is whisked into hot water, instead of steeped, to form a frothy drink. The meditative act of preparing, presenting, and sipping matcha is the backbone of the Japanese tea ceremony. While matcha’s origins are ceremonial, the green tea powder is widely popular around the world in beverages like tea lattes or boba tea, and as a cooking ingredient in everything from ice cream to salad dressing.
Because matcha is made from high-quality tea, and the whole leaves are ingested, it’s a more potent source of nutrients than steeped green tea. In addition to providing small amounts of vitamins and minerals, matcha is rich in antioxidants called polyphenols, which have been tied to protection against heart disease and cancer, as well as better blood sugar regulation, blood pressure reduction, and anti-aging. Another polyphenol in matcha called EGCG has been shown in research to boost metabolism, and slow or halt the growth of cancer cells.
The taste is of matcha is strong. Some people describe it as grass or spinach-like, and it has an umami taste. Because of this it may be sweetened to improve its palatability. One client was thrilled to tell me that he was drinking matcha, but instead of traditional matcha powder, he was drinking a powdered mix. The first ingredient was sugar, and it also contained powdered milk, so it was essentially like hot chocolate—but with cocoa swapped for matcha—something I wouldn’t recommend. Tea experts also warn that with matcha quality is key, and it comes at a cost. In other words, high quality, fresh, pure matcha is expensive. A low price tag can be a red flag for a poor quality product. I like Jade Leaf Organic Japanese Matcha Green Tea Powder ($19; amazon.com), because it's USDA certified organic, third party tested for contaminants, and from Japan.
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.
Do you know what the term “cha” means, which is often found in the names of various qualities of green tea such as gyokurocha, sencha, bancha, matcha, and houjicha? It simply means “tea”, and tea is extremely popular all over India as “cha” (in Bengal & adjacent states) and “chai” in other areas. Just some fun facts for you to share with other tea lovers over your next cup of green tea!
If you do choose to try a tea detox, the most important aspect isn't the kind of healthy tea you choose—it’s what else you eat: “Tea can only be medicinal and detoxifying if your diet isn’t taxing your system, which most American meals are guilty of,” says Lagano. In order to truly detoxify your body, cut processed and fried foods, and up your intake of fruits, vegetables, whole grains, lean proteins, and anti-inflammatory fats like avocados and almonds, says Villacorta. Once your diet is clean and gentle on your body, detoxifying teas can begin to enhance your natural organ function.
Asian countries like Japan and China are the biggest producers of green tea (they produce the best quality too) and are also its biggest consumers. Green tea available in other markets is found in far smaller quantities than black tea. Moreover, it is still gaining popularity, and you can get it at any modern shop. You can also order it from a local tea supplier, over the phone or on the internet. It is almost invariably imported from China (cheaper) and Japan (more expensive) and is packed in sealed packs of 200 grams, 250 grams, and 500 grams. Buy smaller quantities if possible, so that you get to make a fresh brew. Also, always check the date of manufacturing and packing before you buy.