Friday, May 13, 2011

An intro to green tea

I’m a huge fan of green tea. I usually start my day with a few cups of a nice, strong brew, which to me are like a life-giving beverage. Not merely an eye-opener, green tea is a restorative that reinvigorates the body with its potent blend of antioxidants, vitamins, and minerals.

Though tea has been a much-beloved beverage the world over for thousands of years, in recent years, green tea in particular has been discovered to have immense health benefits. A PubMed search for ‘Camellia sinensis’, green tea’s Latin name, yields over 1,100 results, while a search for ‘tea’ yields over 16,000 results, making it one of the most heavily researched substances in the naturopathic toolkit. It’s been studied for a variety of conditions, ranging from cancer to weight loss to arthritis. A complete survey of green tea’s documented health effects is far beyond the scope of this blog, so let’s boil it down by saying, ‘Green tea is good for you.’

The majority of the health effects are due to four main constituents: vitamins and minerals, non-vitamin antioxidants, caffeine, and theanine. To help you on your way, here’s a brief explanation of each.

Vitamins and minerals – Green tea is a veritable multivitamin, as it contains carotenoids (some of which your body converts into vitamin A), ascorbic acid (vitamin C), and tocopherols (vitamin E). These all have antioxidant effects and add to green tea’s benefits. Additionally, a variety of minerals are found in tea depending on the soil in which the tea was grown. Selenium and zinc are some of the minerals found in tea, both of which have antioxidant function in the body.

Antioxidants – The antioxidants in tea can generally be categorized as polyphenols, but are sometimes subcategorized as catechins and gallocatechins. Research has show than these polyphenols are directly absorbed into the bloodstream, where they have a variety of actions, including their main function as antioxidants. As an example of their antioxidant activity, they have been shown to prevent oxidation of LDL (‘bad cholesterol’), thus preventing heart disease. In addition to this primary effect, these compounds are antibiotic, antiviral, immune-stimulatory, antimutagenic (they prevent DNA damage, thus preventing cancer), and improve detoxification by the liver. Could you really ask for anything more?

Caffeine – One of the reasons people avoid green tea is due to caffeine. One of the reasons other people embrace green tea is due to the caffeine. In my view, it’s just part of the tea experience, good or bad. Caffeine’s well-known effects include improved sense of alertness, well-being and energy. As a reference point, the caffeine content of a cup of green tea is about 25 mg, a cup of black tea contains 50-60 mg, whereas a cup of coffee contains 150 mg.

Theanine – A little-known amino acid, theanine is found abundantly in green or white tea, but is not present in black tea (it’s destroyed in the fermentation process). Sometimes described as the compound in green tea that generates the ‘zen’ effect, theanine works by increasing the amount of the calming neurotransmitter GABA. As a result, theanine helps to balance the stimulating effect of caffeine, generating that calm uplift for which green tea is known.

Finally, a brief primer on how to brew green or white tea. I brew almost exclusively loose-leaf tea, and rarely brew flavored tea. Tea is generally flavored to hide unpleasant tastes, either in the tea itself, or as a result of poor brewing – good brewing will allow you to explore the universe of teas in their exquisite natural splendor. Like wine, tea comes in endless varietals that range from the elegantly simple greens of Japan, to the flowery oolongs of Taiwan, the spicy chais of India, and the dignified, formal black English breakfast teas. A trip to your local teahouse will find you oohing and ahhing over the varieties available.

The run-down on brewing green tea:

1) Unlike your standard Lipton black breakfast tea, green tea should never be brewed in boiling water. Boil your water, then let it cool for a minute or two before pouring over tea leaves. Water that’s too hot will make your tea bitter – avoid it.

2) Don’t brew your tea too long. Three to four minutes is generally long enough (a few teas are brewed less), after which you should either fully decant your tea from the pot, or remove your brew basket from your mug of tea. Brewing for too long will also make your tea bitter.

3) Brew your tea a second time! Good quality leaves will be able to be brewed at least twice, some a third or even fourth time. For your second brew, increase the brewing time by a minute or so.

4) And a last tip – most green, white or oolong teas should leave a nutty, sweetish taste in the back of your throat. I’m not sure what the source of that sweet taste is, but it’s an indicator that you are brewing correctly.

And that’s it! There are, of course, more elaborate ways of brewing, including timers, digitally-controlled kettles, and elaborate tea pots, but anyone can make a dang good cup of tea with little more than a brew basket as special equipment.

Regular readers of this column will know the value I put on a simple but balanced diet combined with certain superfoods, such as tea. Not to mention the fact that tea connoisseurship will make you one of the more ~refined~ people you know. To your health!