Thursday, November 20, 2008

The Health Benefits Of Green Tea

As far back as 500,000 years ago, people enjoyed steeping tea leaves in boiling water. Was it the soothing experience that turned people onto tea? Or did our ancestors understand the powerful healing properties of a warm cup of tea? Whatever the reason, the art of drinking tea has become a worldwide phenomenon.

Recent media attention has turned the public's conscience to green tea, an ancient Asian blend that has become massively popular in the Western world. There are a number of outlandish claims regarding the health benefits of green tea being thrown around, so wading through all the BS can be anything but soothing.

So, what are the health benefits of green tea?

What's inside?

To understand the health benefits of green tea, let's first take a look at what's inside each cup:

  • Green tea is chock-full of polyphenols, phytochemicals with potent antioxidant properties that give green tea its bitter flavor.
  • Green tea contains six primary polyphenols, known as catechins.
  • Green tea contains more catechins than black or oolong tea.
  • Epigallocatechin gallate (EGCG) is the most active and studied of green tea's catechins.
  • Green tea also contains alkaloids such as caffeine (although in lower quantities than black tea), which give green tea its stimulating properties.

Is green tea healthy?

If only life were cut-and-dry, this question would have a simple answer. However, as with many natural supplements or remedies, the verdict on green tea is still up in the air. While some studies have suggested that green tea offers health benefits, many institutions, including the National Institutes of Health, agree that there simply isn't enough evidence to definitively proclaim the health benefits of green tea. Keeping in mind that more study is needed, green tea has shown modest benefits for some major health conditions:

Cardiovascular Disease

Several large studies have suggested that drinking green tea reduces the risk of stroke and coronary artery disease, although results are mixed. Green tea may further lower cholesterol, but it seems to have no effect on blood pressure. The FDA, therefore, has rejected a recent bid by green tea makers to allow tea labels to claim that green tea is heart-healthy.


Human studies of green tea in cancer prevention have been conflicting. However, animal studies have been much more convincing. Green tea catechin extracts are thus being investigated for their anticancer properties in current clinical trials.

Weight Loss

Some studies suggest that drinking green tea or taking green tea extract pills can increase metabolism and help burn fat, but results are mixed once again.

Along with those health conditions listed above, other studies have suggested that green tea is helpful for diabetes, stress, dental cavities, protection against UV radiation, and viral infection. The bottom line, however, is that scientists just don't know enough to make any clear recommendations.

How much green tea should I drink?

Now that you understand that drinking green tea may offer some health benefits, why not give it a shot? But how many cups a day should you drink? Well, brace yourself: The majority of studies that found any health benefit had participants drink anywhere from three to 10 cups of green tea daily. In other words -- get brewin'!

How should I prepare my tea?

You'll get most benefit out of freshly brewed hot tea that has steeped for three to five minutes, a process that helps to bring out the catechins. Green tea made from older leaves also tends to have more catechins. Decaffeinated or bottled tea preparations and instant teas have less of those favorable chemicals and compounds, whereas green tea extract capsules provide similar amounts of catechins to freshly brewed tea. Typically, you'll want to take in 250 mg to 400 mg of green tea polyphenols per day or more (equals about three cups per day).

Does adding milk affect my tea?

Though green tea is not normally prepared with milk, one study found that the addition of milk blocked the healthy action of green or black tea catechins. Several other studies, however, have refuted this claim.

Is green tea harmful?

Green tea does contain active ingredients, particularly caffeine, which can cause problems such as an increased heart rate or insomnia for some. Caffeine also crosses the placenta and is found in breast milk, which means that pregnant or breastfeeding women might want to avoid green tea.

Green tea also contains tannin, which may limit iron absorption from fruits or vegetables. Taking tea with some lemon (high in vitamin C) should counteract this.

There are also numerous drugs with which green tea should not be combined. Many of these drug interactions are due to green tea's caffeine content. Green tea should not be mixed with adenosine, beta-lactam antibiotics, aspirin, benzodiazepines, beta-blockers, blood-thinning medications, chemotherapy, clozapine, ephedrine, lithium, monoamine oxidase inhibitors, oral contraceptives, and phenylpropanolamine. For more interactions, speak to your doctor.

going green

Despite the common notion that green tea is a holistic and healthy beverage, current medical studies don't yet seem to agree. While results look promising, more time and effort is needed to fully unravel the mysteries of this ancient beverage. In the meantime, drinking a few cups of green tea a day in place of other less healthy beverage choices is not such a bad idea.

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