There are also several harmful effects of green tea over-consumption that are possible. These include consuming tainted supplements marked as green tea extract, high caffeine consumption, consuming aluminum, and the effects of tea polyphenols on iron bioavailability. Green tea extracts should not be taken by patients suffering from renal failure, liver disease, heart conditions or major cardiovascular problems without supervision from a doctor. People sensitive to caffeine should be careful of their intake. Pregnant and breast-feeding women should drink no more than one or two cups per day, as some research shows that more caffeine than this amount may interfere with normal heart rhythms.
Matcha (抹茶, Japanese pronunciation pronounced [mat.tɕa], English /ˈmætʃə/[i]) is finely ground powder of specially grown and processed green tea leaves. It is special in two aspects of farming and processing: the green tea plants for matcha are shade-grown for about three weeks before harvest and the stems and veins are removed in processing. During shaded growth, the plant Camellia sinensis produces more theanine and caffeine. The powdered form of matcha is consumed differently from tea leaves or tea bags, and is dissolved in a liquid, typically water or milk.
Most importantly, EGCg and other catechins counteract the effects of free radicals from the likes of pollution, UV rays, radiation, and chemicals, which can lead to cell and DNA damage. Since over 60% of the catechins in matcha are actually EGCg, a daily matcha regimen can help restore and preserve the body’s integral well-being and balance. Read more on our Change The Odds Page.
Along with caffeine, which gives green tea its characteristic taste, bitterness, and stimulating effect, green tea is also rich in a group of chemicals, called catechin polyphenols (commonly known as tannins, which contribute to bitter taste and astringency). These catechin polyphenols include catechin, epicatechin, epicatechin gallate (ECG), epigallocatechin gallate (EGCG), and various proanthocyanidins. They are also known as flavonoids and are very powerful antioxidants. Flavonoids, together with some amino acids like thiamine, are responsible for the potent flavor of green tea.
It is used in castella, manjū, and monaka; as a topping for shaved ice (kakigōri); mixed with milk and sugar as a drink; and mixed with salt and used to flavour tempura in a mixture known as matcha-jio. It is also used as flavouring in many Western-style chocolates, candy, and desserts, such as cakes and pastries (including Swiss rolls and cheesecake), cookies, pudding, mousse, and green tea ice cream. Matcha frozen yogurt is sold in shops and can be made at home using Greek yogurt. The Japanese snack Pocky has a matcha-flavoured version. Matcha may also be mixed into other forms of tea. For example, it is added to genmaicha to form what is called matcha-iri genmaicha (literally, roasted brown rice and green tea with added matcha).
Already nearly calorie free, matcha is a great addition to a weight loss program by tackling the problem from both sides. It boosts metabolism and burns fat. One recent study even suggested that matcha may help burn calories by four times. At the same time, matcha does not put any stress on the body. It doesn’t raise blood pressure or heart rate, making it a safe alternative to questionable quick fixes or pharmaceuticals ridden with side effects.
Rooibos or 'red bush' from South Africa is found to be a very potent variety of red tea prepared from the leaves of the herb Aspalathus linearis. Indigenous to the Cape of Good Hope region of South Africa, Rooibos is the only red tea that undergoes a fermentation process similar to black tea. Fermentation turns the green leaves into a garnet colour and lends a very sweet flavor. Rooibos endowed with a very high magnesium ('Nature's tranquilizer') component, acts as a natural adaptogen i.e., that which helps the body adapt to stress.
Japanese researchers published a study on green tea and its effect on the beta-amyloid protein plaques found in Alzheimer’s disease in the April 2008 issue of the Journal of Nutritional Biochemistry. The protein plaques associated with Alzheimer’s disease increase brain cell damage and death due to oxidative stress. The researchers found that green tea catechins reduced the level of damaging free radicals in the brains of rats. The green tea rodents showed much less plaque-induced deficits in memory compared to rodents that didn’t receive green tea and those that were infused with beta-amyloid proteins. (8)