Tea: The Rise of a Healthy Beverage

Legend has it that the tea leaf was first discovered for human use in 2737 BC by the Chinese Emperor Sheng Nung. Emperor Nung was very careful to protect his body from illness, so he would only drink water that had been boiled. One day, the Emperor sat unknowingly under a patch of tea trees. A gust of wind blew two leaves and a bud into the Emperor’s cup while he wasn’t looking, and the gift of tea was first known.

While it may seem that there are countless varieties and species of tea in the world, all the many forms actually come from only one plant – camellia sinensis. The differences are generated in how the tea leaves are grown, when they are harvested, and how they are processed. Without getting into too much detail, a patch of green tea becomes a cup of black tea through an oxidation process in which catechins are oxidized and polymerized to form theaflavins and thearubigens, which account for the more bitter and astringent taste. Ooling is formed through a similar process, but the tea is only fermented for half the amount as black tea. White tea is differentiated by the time of its harvest, when the tea leaves are still young and haven’t developed to the size of a standard green tea leaf. While the Western world has primarily consumed black tea throughout history, green tea and other varieties are now becoming more popular, along with an increased interest in the many health benefits that tea has to offer.

The health benefits of tea are vast and wide-ranging. Studies have shown tea and its active components to have many benefits in treating cancer, cardiovascular disease, weight gain, diabetes, as well as general disease prevention through the promotion of the immune system.

One great property of tea is its high amounts of the popular compounds known as anti-oxidants, which are important in disease prevention. Anti-oxidants prevent the oxidation of lipids in our bodies by sequestering scavenging oxygen species and free radicals. Unchecked or unbalanced oxidation of such species over time can lead to a disease state. While all the various forms of tea do contain anti-oxidants, the highest levels are generally found in green tea…the fresher the better!

The majority of research into the health benefits of tea has centered around a group of compounds called flavanoids, and more specifically, catechins. These catechins are naturally very rich in anti-oxidants. As oxidative damage is an important step in cancer development, catechins can possibly aid in preventing the normal cell from becoming malignant. One intersting study demonstrated this as green tea catechins inhibited cigarette smoke induced DNA breakage in cultured lung cells by blocking production of oxygen free radicals. Tea flavanoids can also be beneficial in cancer treatment to help the body recover from chemotherapy. Along with tumor regression, chemotherapy can also be toxic to the host’s immune system through oxidative stress and liver damage. While activating and promoting the immune system, tea can also aid in the detoxification of our bodily systems. In descending order, the highest amount of catechins are generally found in green tea, oolong tea, and black tea.

The flavanoid content of tea consumption is also linked to the protection of the cardiovascualr system through prevention of LDL oxidation, lowering serum lipids, having an anti-inflammatory effect, and inhibiting platellet aggregation. Tea catechins have also been found to prevent accumulation of sugar in our bodies, and the lipids produced by sugar, showing prevention benefits for weight gain and diabetes. On top of all this, it can also greatly aid in our digestive processes!

Whether it is a masala chai, sencha green, or oolong peach, as you bring that cup of steaming calm energy to you lips, think of the many places it has come from, and the many benefits it has to offer. So much gratitude to be found, in such a simple cup of tea.

 

References: Banerjee & Chaudhuri (2005). Therapeutic Effects of Tea.

                   Karudo & Hara (2004). Health Effects of Tea and its Catechins.