Health Effects of Tea

Glass Teapot

Numerous beneficial health effects of tea have been documented in research and studies. But with more than 3,000 varieties of tea out there, are we to assume that these health benefits are the same for black, oolong, green, white tea and herbal infusions?

Read on and you’ll find out!

Black tea, green tea, oolong tea and white tea all originate from one plant called Camillia Sinensis. The differences between tea varieties come from the way tea leaves are processed.

Leaves that are fermented the most (or the most exposed to oxygen) are classified as black. Green tea leaves are partly processed; oolong tea falls somewhere between black and green; white tea leaves are unprocessed. The requirement to process tea leaves originated from a need to better preserve their taste and freshness many centuries ago.

But what about herbal tea you ask?

Well… it doesn’t come from the same plant at all… So technically, it’s not even ‘tea’!

Health Effects of Tea – Caffeine

In dry form, a kilogram of black tea has twice the caffeine as a kilogram of coffee…

But one kilogram of black tea makes about 450 cups of tea and one kilogram of coffee makes about 100 cups of coffee, so…

There is less caffeine in a cup of tea than in a cup of coffee.

Green teas have less caffeine than black teas, and white teas have even less caffeine than green teas. Oolong teas fall between black and green teas. Herbal tea, because it is not made from the same tea plant, is caffeine-free, naturally.

Here is a graphical representation of their respective caffeine content.

caffeine content in coffeecaffeine content in black teacaffeine content in oolong teacaffeine content in green tea
Black Tea
Oolong Tea
Green Tea
70 – 180 mg
of caffeine
25 – 110 mg
of caffeine
12 – 55 mg
of caffeine
8 – 16 mg
of caffeine

The exact quantity of caffeine in your tea will depend on where the leaves were located on the plant, the location of the plant itself (i.e., country, type of soil, etc.), the way the leaves were processed and the recipe you used to make your cup of tea (i.e., the water-to-tea ratio and steeping time).

So, I can’t really give you an exact number as to how many milligrams of caffeine you’re ingesting, but the previous information should be helpful. Contact the manufacturer if you need more precise information or learn how you can make decaf tea out of regular tea.

Beneficial Health Effects of Tea

Berries Sampler

Teas, and especially white tea and green tea, can help promote the following health benefits:

  • Stimulate mental clarity
  • Reduce the risk of certain cancers
  • Reduce the risk of heart disease
  • Lower blood sugar levels
  • Help prevent viral infections
  • Help prevent bad breath
  • Help prevent tooth decay

Also, because tea requires its water to be boiled, drinking tea is safer than drinking water!

Detrimental Health Effects of Tea

Some people may not react well to drinking too much tea.

If you suffer from fibrocystic disease or have high blood pressure, you shouldn't ingest too much caffeine.

Tea is better than coffee, but it still contains caffeine.

If you need to decrease the amount of caffeine in your tea, you can buy decaf tea or make a “second cup”. Here’s how to make your own decaf tea at home:

  1. Make yourself a cup/pot and let it steep as you would normally do.
  2. Discard the water (your actual tea).
  3. Reuse the same tea leaves/tea bag to make a second cup/pot. This second pot/cup will contain significantly less caffeine than the first pot.

If you’re actively trying to limit your caffeine intake but still want to drink tea, your best options are decaf, white and green teas, which have less caffeine than oolong and black teas.

Polyphenols and Their Benefits

Polyphenols (also called tannins) are present in all tea leaves but they’re more concentrated in young buds and leaves. Polyphenols give the tea its color and pungency. By fermenting the leaves, some of the polyphenols are oxidized and become soluble in water. These water-soluble tannins give a darker color to the tea.

Polyphenols that aren’t oxidized (i.e., those in green tea) give tea its pungency. This is why green tea isn’t dark but can be more bitter. This is a general rule, so there are exceptions, of course…

Jumbo Cup & Infuser

Unfermented oils present in green teas can help digestion. During fermentation, some naturally occurring oils can also ferment and the resulting flavor of the brewed tea can include a combination of both unfermented and fermented oils that evaporate once in contact with hot water.

It’s why you should cover your tea while steeping it.

Maximize the Beneficial Health Effects of Your Tea

To reap the maximum benefits from your cup of tea, you should keep your stash in the right conditions.

Typical shelf life for green/white tea is about 6 months, and up to a few years for oolong and black teas. Keep in mind that pellets or twisted leaves last longer than flat exposed leaves. Keep your tea in a cool, dry and dark place, and in an airtight container.

More Information About Tea and Healthy Drinks

Tea Starter Set

You can read more interesting facts about tea here.

Consult the sidebar (located on the right or below) to view a list of articles that cover the health benefits associated with specific tea types, along with recipes for chai tea, and several herbal tisanes or infusions.

You can visit our comfort food section for great recipes to enjoy at home while sipping your favorite cup of tea, including these delicious and healthy tea scones.

You may also be interested in learning more about juicing, especially the benefits of wheatgrass juicing.