Green tea has a long tradition that dates back more than 5,000 years, to the time of imperial China. It’s been known for centuries to have many health benefits, including longer life and reduced occurrence of some chronic diseases. However, most people drink green tea for its restorative and calming effects.

What makes green tea different from black tea is that it’s made from leaves of the Camellia sinensis plant (the tea plant) that have not been allowed to oxidize. This gives green tea its slightly sweeter flavor and pale color in comparison with black tea.

There are literally more than 600 different variants of green tea, known as “cultivars”. The aroma and flavor profile will differ, depending on growing conditions, production and processing, horticultural techniques and the timing of the harvest.

Most green tea in the market today is from China. It’s known for its “vegetal” taste that comes from a unique process and preservation of the leaves from oxidation that makes it some of the most sought-after tea in the world.

The most famous green tea is known as Long Jing (literally “dragon well”), which comes from China’s famous Zhejiang Province. Other variants from this famous tea-growing region include Huiming, Hua Ding, Kaihua Longding, and Gunpowder.

Other Chinese provinces that are known for their green tea production include Jiangsu Province (home to Bi Luo Chun), Fujian Province (home to mountain-grown organic green tea, as well as oolong tea and white tea), Anhui Province (home to Da Fang) and Henan Province (known for Xin Yang Mao Jian).

While 80 percent of the world’s green tea still comes from China, it’s possible to find high-quality green tea from other countries such as Japan, Vietnam, and Indonesia as well. Outside of China, the next most famous region in the world for tea is Japan.

In fact, within Japan, green tea is simply known as “tea.” While the Chinese prefer to pan-fire their teas, the Japanese tend to steam theirs, giving them a more “leafy” taste. Japanese teas are made from the Yabukita cultivar of the tea plant. There are many famous variants of green tea within Japan, including green matcha tea.

Regardless of the origin of the tea, all forms of green tea are typically associated with a number of health benefits. These include everything from lower incidence of cancer to improved cardiovascular health, lower risk of mortality, and less risk of suffering from chronic disease. Other studies have suggested a link between green tea and blood sugar level as well as blood concentration of cholesterol.

However, scientists have thus far been able to pinpoint the exact mechanism that creates these benefits. After all, green tea is 99.9% water. In terms of pure nutritional content, green tea may seem rather limited. After all, every 100 g of brewed tea consists of only a few trace amounts of vitamins (e.g. Riboflavin, or B2) and minerals, such as manganese and potassium. There are 0 g of carbohydrates and 0 g of fat in 100 g of brewed tea.

So where do the health benefits come from?

It’s the other 0.1% that matters. The remaining 0.1% is primarily comprised of phytochemicals such as caffeine and two specific types of antioxidants, known as flavonoids and catechins. These catechins are rich and powerful antioxidants that protect the body. L-Theanine helps provide calmness while the Caffeine keeps you alert. Green tea is also known to support metabolism and fat burning but who knows!

What we do know is that drinking green tea can be the key to unlocking lots of health benefits. And now modern science may be on the cusp of discovering the exact mechanisms of how this works. Until then keep green and keep alert.