Green tea: choose your weapon

If you want the disease-fighting power and health benefits of green tea, it's best to get out your kettle and brew your own -- because some bottled teas contain all the nutrients of a glass of rainwater.

In other words, practically none at all.

One of the best antioxidants in green tea, for example, is a catechin called epigallocatechin gallate, or EGCG for short. It's been shown to fight dementia, cancer, and more.

(To learn more about green tea's dementia-fighting powers read this.)

But Diet Snapple Green Tea was found to have just about none of these health benefits of green tea, according to a series of tests conducted by ConsumerLab.com. Honest Tea's Green Tea with Honey did a little better -- but not by much. The label claims each bottle contains 190 mg of healthy catechins, but ConsumerLab.com's tests found just 60 percent of those levels.

Maybe it's time to change the name -- because that's not exactly what I'd call an "honest" tea.

Clearly, you want to stick to loose teas and teabags with the largest amount of health benefits of green tea instead -- but even then, the choice isn't as cut-and-dry as it might seem. Lipton and Bigelow, for example, contain high levels of antioxidants at a low price -- and very little caffeine, too.

But don't stock up just yet -- because both contain lead, according to the test results.

It could be because Lipton and Bigelow's green teas are grown largely in China, where lead contamination in the soil is all too common. While the lead seems to stay in the tea and not leech out into the water, I wouldn't take the risk myself.

Teavana's Gyokuro green tea from Japan contains no lead and even higher levels of antioxidants. On the other hand, it also comes with a much higher price tag and as much caffeine as a cup of coffee.

I won't recommend a specific brand, since it seems like there are tradeoffs all around. For the best results, avoid bottled teas and stick to green teas grown in safer regions to get the largest amount of health benefits of green tea.

And if you're sensitive to caffeine, be sure to purchase a decaffeinated version.