Green tea is rich in catechins, which reduce the proliferation of blood vessels needed for tumors to grow and metastasize. It also acts as a powerful antioxidant, activates enzymes in the liver that help rid the body of toxins and facilitates the death of cancer cells. (Black tea, on the other hand, is fermented, which destroys catechins.)
Buy either the Japanese leaves (They’re considered the best)* or the Chinese Dragonwell brand, and drink a few cups a day (Some say 2-3; others say up to 6.) It does have caffeine (about 20 percent the amount in coffee), so don’t drink it on an empty stomach and switch to decaffeinated in the p.m. Caffeine raises your blood sugar.
Here’s how to make the perfect cup: Bring water to boil, and then let it settle down for a minute or so ‘til the bubbles disappear. Add leaves (2 grams/.07 ounces per cup, but you don’t have to be so perfect), and let them steep for 10 minutes so that they release the catechins. Drink within the hour; with time, the steeped tea loses its catechins. You can re-use the leaves later in the day for a second cup.
*Author’s note: Since the writing of this post, Japan has unfortunately experienced a nuclear disaster that leaves its food supply in question. For the moment, you’ll probably want to find an alternative source–from Sri Lanka or India, for example.