Monday, November 28, 2005

More on tea, those crazy free radicals.

Most people I know, hardened tea drinkers among them, do not realize that green tea and black tea both come from the same plant -- Camellia sinensis. The difference is how they're processed. Black tea is fermented, and green tea is not. Teas like Oolong are partially fermented. Fermentation means that the leaves are smacked around a bit to bruise the cell walls, laid out to oxidize -- then dried later. The oxidation of the plant compounds changes the color and flavor of the tea considerably. This is why green tea, which is not oxidized, contains more antioxidants.

Whether green or black, to prepare the tea so that it tastes best, boil water, then let the water rest for a few minutes before adding the bag. The water should not be at boiling temperature (212 degrees F), but a bit lower (180 degrees F). A couple of minutes should do it.

Not so rooibos. You can put the bag right in when it's hot as heck, even boil the tea for a while and because it's different chemically it won't taste bad (just stronger).

Rooibos tea is processed in a similar manner as traditional tea - the fermented rooibos is very red, has a fruity flavor, and has less antioxidants than green, or unfermented Rooibos. (I prefer the green over the red for taste alone -- it is remarkably mild and very similar to green tea without the astringency. Astringency is that part of tea that makes you pucker slightly (or more than slightly if you overbrewed) and makes your mouth feel dry.

I've been testing the green rooibos, steeped or boiled for 10 minutes. The boiled has the highest antioxidant activity.

A bit on tea and cancer.

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Most people have heard of free radicals. Free radicals are formed when oxygen reacts with a normally stable molecule, making it unstable. To stabilize itself, it steals electrons from other formerly stable molecules and so on, until something puts a stop to it. So what the fuck does that mean?

Okay. Picture 10 fine fellows holding up a heavy glass ball. Along comes some bastard with only one shoe, and seeing that fellow #1 has a match to his own, he runs over, unties the damn thing and tears it off. Fellow #1 struggles to keep his footing, but the glass ball remains intact. But now he has only 1 shoe. And the floor is cold. So he lets go of the ball and steals the next fellow's shoe. All this activity upsets the ball, and it bangs against a wall and sustains a small crack. Now stuff can get in the ball, but it's still a ball. Fellow #1 goes back to holding the ball, but now fellow #2 is now stealing from the third guy, and so on. It upsets the balance. If two guys both simultaneously have shoes stolen, the ball topples and breaks.

And this is like a cell. Cell cracking = cell damage. Now a carcinogen has easier access to your genetic material -- your DNA.. Cell breaking = cell death, and you know, that can't be good.

An antioxidant is a fine fellow wearing two shoes and carrying a third. He runs up to Fellow #1, puts the extra shoe on his foot, laces it up and no one knows the better for it.

We make some antioxidants in our bodies, like superoxide dismutase, and we eat some, like Vitamin C, E and beta carotene, the precursor to Vitamin A. But like I said, as we age, we can use a bit of help. Like most things, it should be noted that oxidation is a balance. We need oxygen, and we even need some reactive oxygen species, because ironically, our immune system uses them to destroy bacteria. But not too much, or the good stuff goes too. If a cell is compromised enough, the free radicals mess with your DNA, the mutation survives, and cancer or other awful crap begins.

So...drink your tea. Eat your greens. And be nice. It couldn't hurt, especially around this time of year. Back with more gripping food smack in a bit.


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