This is part of our ongoing The Best Kept Secrets to Healthy Aging spotlight. Each day, we will be posting some of the great information that’s packed into our book, The Best Kept Secrets to Healthy Aging.
Green Tea – Drinking Your Way to Health and Longevity
Tea made from the leaves of the Camellia sinensis plant has been consumed for over 5000 years. After water, tea is the most popularly consumed beverage worldwide. Europeans, North Americans and North Africans drink mainly black tea, Asians seem to prefer green tea, and oolong tea is popular in China and Taiwan.
Tea is tasty, soothing and either warming or cooling (depending on whether you drink it hot or cold). But tea is so much more than that – it is a well-recognized enhancer of the health and performance of your heart, your cardiovascular system, your muscles, your teeth and your bones – just to name a few reasons why this natural food is so beneficial.
What Difference Does the Color of Tea Make?
Whatever its color or name, all true “teas” are produced from the leaves of the tropical evergreen plant, Camellia sinensis. When tea leaves are converted into black tea, the harvested leaves are allowed to ferment before and while drying – an oxidation process that changes both the color of the leaves and the nature of their phytochemical contents. In contrast, the leaves for green tea are steamed to prevent oxidation and phytonutrient change during drying. Oolong tea is produced by allowing a partial oxidation of the leaves, making oolong tea equivalent to “half-green and halfblack” tea. About 20% of the tea produced worldwide is green tea. Essentially, then, with changes in the phytonutrient profiles, drinkers of the different types of tea can experience differing beneficial effects. Each phytochemical has unique healthful properties and, as antioxidants, has affinities for different types of free radicals.
What Does Green Tea have that is missing from Other Beverages?
Tea is a rich source of “polyphenolic phytonutrients.” While this class of phytonutrients is huge, with over 4000 known members, tea leaves become heavily loaded with one particular class of phytonutrient during their growth. In unoxidized, unfermented green tea leaves, this class, the catechins, includes epicatechin (EC), epicatechin-3-gallate (ECG), epigallocatechin (EGC) and epigallocatechin-3-gallate (EGCG). During the oxidation process of converting green tea to black tea, the catechins also are oxidized, changing into a class called the theaflavins: EC becomes theaflavin, ECG becomes theaflavin-3- gallate, EGC becomes theaflavin-3í-gallate and EGCG becomes theaflavin-3,3í-digallate.
It has been estimated that one cup of brewed green tea contains between 100 and 150 mg of catechins, of which about half is EGCG and a little less than half is EGC. The other catechins are present but in much smaller amounts. Hot water extraction (brewing) maintains these relative proportions; EGCG comprises about half of the dissolved solids in brewed green tea.
Next Best Kept Secrets to Healthy Aging topic:
Green Tea – Does the Source of the Tea Matter?