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.
One of the key components in Matcha is the amino acid L-theanine, which is found almost exclusively in shade-grown green teas like Matcha. When L-theanine is combined with the natural caffeine in tea, it metabolizes more slowly, releasing the caffeine over a longer period of time and providing a stable three to six hour long energy boost (versus coffee caffeine at an hour to an hour and a half).
Rooibos contains polyphenols that have anti-inflammatory, antiviral, and antimutagenic qualities. Polyphenols are organic chemicals that are often praised for their antioxidant capabilities. Studies suggest that regularly drinking organic red rooibos tea provides the liver with potent antioxidants, helping the organ to improve detoxification. Antioxidants act as scavengers of free radicals throughout the body, which are detrimental byproducts of cell metabolism that can cause cancer and heart diseases. Aspalathin and nothofagin are two other vital antioxidants that rooibos tea contains, making it a great beverage to boost your immune system and protect your body against all types of diseases.
Short-term studies have shown that drinking tea may improve vascular reactivity—a measure of how well your blood vessels respond to physical or emotional stress. There's also evidence that drinking either black or green tea may lower harmful LDL cholesterol levels. Blood pressure may also dip slightly in people who drink tea, but results from these studies have been mixed.
Grown under shade for three weeks prior to plucking, gyokuro is one of the most exclusive varieties of tea produced in Japan. The shading technique imparts a sweeter flavor, and produces a particularly rich color thanks to the higher amounts of chlorophyll in the shaded leaf. Gyokuro tea is associated with the Uji region, the first tea-growing region in Japan. It is often made using smaller-leaf cultivars of the tea plant.