Starr Environmental / Flickr

Camellia sinensis

Tea is the dried and processed leaves of Camellia sinensis. These leaves make up 4 major groups of tea: Black, Green, Oolong and White.

Black tea is produced when the leaves are picked, rolled and left to dry in the sun. The rolling breaks the leaves open, which causes it to oxidize and become darker. After they are rolled they are left to dry in the sun. Black tea has the strongest flavor of the camellia sinensis teas and has the highest content of caffeine. The amount of caffeine in black tea is about one third the caffeine found in a cup of coffee. Black teas contain the highest amount of caffeine followed by Green tea, Oolong and White tea. It also lasts on the shelf longer than Green, White and Oolong teas. If stored properly, it can sit for years without losing its flavor.

Oolong tea is slightly less oxidized than Black tea and it has less caffeine than Black tea.

Green tea is steamed, rolled and dried immediately after being harvested, which stops the oxidation process. This is how the leaves stay green even though they are rolled.

White tea undergoes the least processing. The youngest tea buds are picked and air-dried.

The leaves of these types of teas contain a large reservoir of healthy compounds that fight off diseases. Some of these healthy compounds are called catechins. The most popular catechin is a powerful antioxidant called EGCG (Epigallocatechin gallate). Some of the other powerful antioxidants in these teas are called tannins, such as Gallic acid, and the other antioxidants are flavanoids and polyphenols.

Adding milk, non-dairy creamers or soymilk, to these teas can reduce the effect of the health benefits on the body. Milks can keep teas from enhancing the effects of insulin on the body.

On the other hand, drinking tea with some lemon (or any citrus fruit) can make the water more acidic, which may actually keep the antioxidants (most of which are acidic), from breaking down. Dunking the tea bag in the tea or having the leaves straight with no bag can release more cancer fighting molecules since more of the surface area of the leaf is exposed to the water.

These teas contain an amino acid called L-Theanine. This amino acid signals the brain to calm down by helping it to release more alpha brain waves. These kinds of brain waves are associated with feelings of tranquility, awareness, wakefulness and peace. Black tea contains more L-theanine than green, oolong or white teas. It can also help improve your mood because Camellia sinensis teas are adaptogens. This special group of foods can help make your body resistant to stress. These teas can be effective stress reducers and anxiety relievers and they can help buffer the effect of the caffeine has on the body.

One large study has shown that tea can have a memory enhancing effect on the brain. Whether it can help keep Alzheimer’s away is still unclear. Another study suggests that Camellia sinensis teas can reduce the risks of atherosclerosis, cardiovascular disease, inflammation and diet related obesity. It may also possibly act as an ACE inhibitor, which means it can help lower your blood pressure. According to one very large Japanese study, people who drank teas with caffeine or coffee were less likely to die of cardiovascular disease.

The great thing about all the Camellia sinensis teas is that they can reduce your risk of virtually all the cancers out there. Most of these benefits can be seen when you drink 5 cups of the tea per day. However, 7-10 cups per day may also help fight off pancreatic cancer and liver diseases.

1 cup of tea  =  120ml (approx 4 ounces)  =   2.5g of green tea leafs

Hibiscus Tea                               Olga_Danylenko / istockphoto

Herbal Teas

Herbal teas are infusions of various leaves, flowers, dried fruits and or herbs. They are not in the same family as the Camellia sinensis teas but they have their own unique combination of antioxidants and disease fighting compounds, some of which overlap with the Camellia sinensis teas, that can also calm the body and fight off diseases ranging from the common cold to cancer. Most herbal teas are caffeine-free.

There are many types and variations of Camellia sinensis teas. Try the 4 major types first and then branch out and explore their variants. This will help you figure out which type of flavor is right for you. For example, Assam and Darjeeling teas are both Black teas but you may prefer the flavor of the Assam tea’s darker and full body taste over Darjeeling tea’s lighter yet flowery taste. Likewise, Oolong teas from different regions of the world can have a wide range of flavor. Even teas from the same region can vary substantially because of soil conditions, weather conditions, pesticide use, the timing of the harvest, and the individual who prepared the leaves.

Darjeeling tea leaves                        yoppy / wikipedia

The health benefits and tastes of teas can be enhanced when certain spices or herbs are added to them. There are a wide variety of combinations that result in a wide range of tastes and health benefits. Some  beneficial spices include: Cinnamon, Cloves, Cardamom, Turmeric, Ginger, Mints and Cumin to name a few.

A good example of a mixed tea is Chai tea (Masala Chai), which is a mix of Assam tea leaves and Indian herbs and spices. There is no one way to make Chai tea since everyone has their own unique blend of spices and herbs that one can use. Another example of a mixed tea is Earl Grey tea, which is a mix of Black tea leaves and bergamot orange oil.

Chai Tea leaves                                      Editor at Large / wikipedia

Here are more ancient combinations of spices for teas and their health benefits from the Dr. Oz Show:

Click on the images to learn more

Tea grades

Camellia sinensis Teas

Chamomille Chashitsu_LaSere Flickr 3723948898_5d9cf8d042_o

Herbal Teas


  1. Mineharu Y, Koizumi A, Tamakoshi A, et al. Coffee, green tea, black tea and oolong tea consumption and risk of mortality from cardiovascular disease in Japanese men and women. Journal Of Epidemiology And Community Health [serial online]. March 2011;65(3):230-240.
  2. Shukla Y. Tea and cancer chemoprevention: a comprehensive review. Asian Pacific Journal Of Cancer Prevention: APJCP [serial online]. April 2007;8(2):155-166.
  3.  Fujiki H. Green tea: Health benefits as cancer preventive for humans. Chemical Record (New York, N.Y.) [serial online]. 2005;5(3):119-132.
  4. Nobre A, Rao A, Owen G. L-theanine, a natural constituent in tea, and its effect on mental state. Asia Pacific Journal Of Clinical Nutrition [serial online]. 2008;17 Suppl 1:167-168.

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