Thursday, January 18, 2007

Bad news for bottled tea (and decaf and instant, too)

This is bad, bad news for anyone who sells or drinks decaffeinated green tea, instant green tea, or ready-to-drink green tea. But it's great news for fans of natural loose-leaf green tea (such as that humbly offered by yours truly).

Last month, the U.S. Department of Agriculture released an update of its database on the flavonoid content of foods. (Flavonoids, also called bioflavonoids, are a category of compounds that include catechins and other strong antioxidants. Scientific evidence has consistently shown that eating foods high in flavonoids reduces your risk of cancer and heart disease.)

The USDA's numbers haven't changed much since the first release of the database. Still, the new release provides a good occasion to revisit the clear superiority of natural loose-leaf green tea when it comes to the health benefits that we all expect from our green tea.

Take epigallocatechin gallate (EGCG), for instance. EGCG is not only one of the most important flavonoids in green tea (because of its powerful antioxidant properties); it's also found only in green tea.

The USDA database tells us that brewed loose-leaf green tea contains 77.81 milligrams of EGCG per 100 grams of infusion. Decaffeinated green tea, however, contains 66 percent less EGCG—only 26.05 mg/100 g.

For green tea that comes ready to drink in a can or bottle, the news is even worse: its EGCG count is a measely 3.96 mg/100 g, or only 5 percent of the EGCG content of brew-it-yourself loose-leaf tea.

(The reason is that within a couple of hours of brewing, green tea catechins begin to break down. The lesson, grasshopper, is that if you want bottled or canned green tea that's rich in catechins, you must go to the factory, snatch it as it rolls off the line, and guzzle it down quickly as you use your kung-fu techniques to escape the security guards chasing you.)

Bringing up the rear is instant green tea, which barely registers with an EGCG count of 0.45 mg/100 g (decaf instant) or 0.49 mg/100 g (regular instant). The cruel math says that's only half a percent as much EGCG as natural loose-leaf green tea.

To summarize, brewing your own hot, tasty green tea infusion from natural loose-leaf green tea is the healthiest way to go—and the tastiest, too.

And there are no security guards to deal with, either.

By the way, you can download the full "database" (actually a PDF file) here.

—Mellow Monk

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