Tea Time

tea pot and cup of black tea

Do you reach for a cup of tea when you’re relaxing, feeling ill or sharing a plate of cookies with friends? You wouldn’t be alone if tea is one of your favourite drinks. After water, tea is the world’s most popular beverage. It is also believed to have health benefits. Read on to find out more about tea.

Know your tea

Tea is made from the leaves and buds of a plant, the Camellia sinensis evergreen. The colour of tea will depend on how long the plant’s leaves are processed and how much contact they have with oxygen. A short processing time will produce a light tea with a strong flavour, such as green tea. A longer processing time will create a darker, fuller flavoured tea, like black tea.

Tea is grown around the world. The more than 1500 kinds of tea fall into three main groups – green, black and oolong. 

Black tea: North America’s favourite tea, black teas usually have a very rich flavour because of their long processing times. Examples of black tea are Earl Grey and English Breakfast.

Green tea: This is most popular in Asia, but is becoming more well-known in North America because of its potential health benefits. It is light in colour and refreshing because of its short processing time. An example of green tea is Matcha. Similar to green tea is white tea, which is made from the youngest of the buds and leaves of the tea plant.

Oolong tea: This is a popular tea in China. It tastes like a mix of black tea and green tea with a pleasant flavour and aroma. An example of oolong tea is Black Dragon.

**Herbal teas do not come from the Camellia sinensis plant.  They are made from the roots, barks, leaves, seeds or flowers of other plants. Examples of herbal teas are chamomile and Rooibos (also called red tea). 

Did you know? When the word “tea” is used to describe a mealtime, it refers to the mid to late afternoon meal that is traditional in England and other countries with British roots. At this meal, tea is served along with finger foods such as sandwiches and scones.

Tea and caffeine

Most teas do contain some caffeine. On average, there is about 25-110 mg of caffeine in a cup of black tea, which is less than a typical cup of coffee. The amount of caffeine will depend on the water temperature, the number of tea leaves brewed and the length of time the leaves are steeped. The hotter and darker coloured your tea, the more caffeine it has. The amount of caffeine is not affected by whether you use a tea bag or loose leaves to make your tea.

For more on caffeine: Filling it to the Rim

Tea and antioxidants

All teas contain a group of disease fighting compounds called polyphenols, which act like antioxidants. Teas that are less processed, such as green or white tea, contain more polyphenols than black tea. Because of the polyphenols in tea, researchers have looked at whether drinking tea can help prevent diseases like cancer or heart disease.  

The amount of antioxidants in your cup of tea will depend on a number of factors such as the water temperature, how long the tea was brewed and how many tea leaves were used for the cup of tea. Even the age and storage conditions of the tea leaves can affect the quality of the antioxidants. All these reasons make it hard for researchers to figure out the effect that tea drinking has on health.

Not all teas are equal. The antioxidant content of these types of teas is lower than brewed teas:

  • Decaffeinated teas
  • Flavoured brewed green teas (for example, lemon-green tea)
  • Ready-to-drink tea (either plain or flavoured)
  • Iced teas
  • Instant, sweetened, flavoured and powdered teas

Many herbal teas also contain antioxidants. However, their antioxidants are not the same as the antioxidants in green, black or oolong teas because they come from different plants.

TIP: Even though teas are a good source of antioxidants, the best way to get a wide variety of antioxidants is from vegetables, fruits and whole grains. 

Are there health benefits to drinking tea?

Maybe. There is much research underway looking at whether tea –especially green tea – can lower your risk of developing chronic diseases like cancer, heart disease and diabetes. Scientists are also looking at whether drinking green tea can prevent obesity and brain diseases like Alzheimer’s. Some studies show that tea does have health benefits, while other studies show that tea has no impact on human health. What we do know is that much more research will be needed before we can make any specific recommendations about tea.

Are there any side effects to drinking tea?

  • Green tea may interact with blood thinning medications (like warfarin). The risk is very low, but if you take warfarin you should speak to your health care professional about your food choices. 
  • The long-term side effects of green tea extracts (in pill or powder form) are not known. There have been reports that people who have taken a large number of these supplements have experienced side effects to the liver.  Health Canada recommends that if you have a history of liver trouble or are pregnant or breastfeeding, you should speak to your doctor before taking green tea extract supplements. 
  • The polyphenols in tea can affect how you absorb iron from plant foods. If you are concerned about your iron levels, you may want to avoid drinking tea with food. 
  • Brewed teas do contain caffeine. In some people, caffeine can cause side effects such as rapid heartbeat, irritability and trouble sleeping. Caffeine in moderation (no more than 300-400 mg/day for adults) is not likely to be a problem for healthy people. If you are sensitive to caffeine, choose herbal teas instead.

The bottom line

Scientists are studying how the antioxidants in tea may help prevent chronic diseases. Most research has compared tea drinking societies to non-tea drinking societies, or has been done on animals. We need more research on humans before we can say for sure that drinking tea prevents disease.

However, tea does have other benefits:

  • Unsweetened tea is calorie-free.
  • Drinking tea adds to your fluid intake to help you stay hydrated.
  • Adding milk to your tea will give you a calcium boost.
  • Taking a break with a soothing hot drink can help you relax and reduce stress.
  • Tea can be used to add a unique flavour to food. Try this recipe: Tea Poached Salmon with Fruit Salsa

One day we may have a better understanding of how tea can impact health. For now, you can feel good about enjoying tea as part of a healthy lifestyle.


Last Update – April 12, 2021

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