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Tea Time - Have you had your Cuppa?

Article written by Germaine Guzman.

Tea is a very versatile beverage that may be consumed in a number of ways at any time of the day. There’s no right or wrong way to serve tea. With their unique flavours, this ‘pot of gold’ can be served hot, iced, strong, mild, sweet or plain. You decide! In fact, after water, tea is the most widely consumed beverage in the world!6

I too, perform my own ritual of making the perfect cup of tea every afternoon, and at times this is accompanied by a sweet treat! But what’s so special about tea may you ask? Besides its versatility, this popular beverage beholds valuable health benefits.

What is Tea?

Tea is an infusion of the leaves of the Camellia Sinensis plant.3 In 2003, world tea production was 3.15 million tonnes annually. The largest producer was India, followed by China (the order has since reversed), followed by Kenya and Sri Lanka.6

Tea contains catechins, a type of antioxidant. In a fresh tea leaf, catechins can make up to 30% of the dry weight. The highest concentration of catechins are found in white and green teas, while black tea has substantially fewer due to oxidation (exposure to oxygen which breaks down these catechins).6

Let’s talk about antioxidants for a moment...

The human body constantly produces unstable molecules called oxidants, also commonly referred to as ‘free radicals’.5 The process of oxidation which produces free radicals in the human body can damage cell membranes and other structures including cellular proteins, lipids and DNA.1 The body can cope with some free radicals and actually needs them to function effectively. However, an overload of free radicals has been linked to certain diseases. Oxidation can be accelerated by other factors including stress, cigarette smoking, alcohol, sunlight, pollution and other factors.1
Antioxidants are substances in certain foods that allow the human body to scavenge, seize and neutralize oxidants or free radicals.1, 5 Think of them as hunters looking for their prey! They help protect the body against the damage from accumulated free radicals. So the strong antioxidant properties of tea (also known as Flavonoids) may be beneficial for health.4

Types of Tea

When tea leaves are intentionally broken or rolled during processing, catechins become oxidized. This is otherwise known as fermentation in the tea industry. This causes them to polymerize (chemically change) and to form larger, more complex antioxidants know as Theaflavins and Theurubigins.3

There are several major categories of tea, which are distinguished by different processing methods:

  1. White tea- is unfermented and made from very young tea leaves or buds that are steamed immediately after harvest to prevent oxidation. This is why their concentrations of catechins are higher than other teas.3
  2. Green tea- is withered by air drying prior to steaming. This is why they have slightly lower catechin concentrations than white tea.3
  3. Black tea- is fully fermented and involves further processing of the leaves, including exposure to heat, light and crushing. This is where the chemical change of catechins into Theaflavins and Theurubigins occur resulting in low catechin concentration.2, 3, 4
  4. Oolong tea- is only partially fermented and is allowed to oxidize for shorter periods than black teas. Consequently, oolong teas fall between green and black teas with respect to their catechin concentrations.3
  5. Herbal teas- are made from a variety of different plants and can include parts other than leaves, including flowers and roots. Most herbal teas don’t contain any ‘Camellia Sinensis’ leaves.2

Tea with benefits

Flavonoid Antioxidants
These are the type of antioxidants found in tea and may help the body protect itself against free radicals- molecules that can damage cells.4

Heart Health
A number of population studies conducted around the world have found that drinking black tea may be associated with a reduced risk of heart disease. Clinical studies, including one in Australia, have shown that tea flavonoids, may promote good heart health by improving endothelial function and by reducing blood cholesterol levels.4

Cholesterol
Four recent studies in people at risk for coronary disease have shown a significant cholesterol lowering effect from tea or tea flavonoids. In another study conducted in Japan, total cholesterol and LDL (‘bad’ cholesterol) were significantly lowered in the tea group while no significant changes were seen in the control group.4 While more research is required, these are promising results.

Immune System
A healthy immune system protects the body from infection and disease. A number of test tube studies have shown that antioxidants found in tea help the immune system response by acting as anti-allergic, anti-inflammatory, anti-viral and anti-bacterial agents. These properties suggest that tea antioxidants help improve resistance to infection.4

Cancer
Population studies suggest that eating a diet rich in plant foods such as fruits, vegetables and tea may be associated with lower cancer risk. Studies appear to indicate that the flavonoids in tea help control progression of cancer by maintaining normal cell growth rate by increasing the natural turnover of precancerous and cancerous cells. The evidence for the flavonoid antioxidants and cancer is still in its early stages and much more clinical evidence is needed before any conclusions are made.4

Weight Management
Unsweetened, freshly brewed tea, both black and green has, with little or without milk, no sugar, little or no fat and virtually no kilojoules. This makes tea an ideal choice for a weight control plan that is part of a healthy lifestyle, especially when substituting for other sugar sweetened beverages.4

Oral Health
Tea is a source of fluoride, a mineral that helps protect teeth by strengthening tooth enamel and combating cavities. Research also indicates that tea antioxidants may inhibit the plaque-forming ability of oral bacteria.4


Now that we’ve delved into the benefits of  your cuppa it is evident to say that drinking tea daily is an easy simple step in the right direction towards a healthy lifestyle.  And with that said, it’s now time for my afternoon ritual...tea-rrific!

References

  1. Deakin University – Better Health Channel, March 2009. Antioxidants [Online]. Available at http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Antioxidants  [Accessed 10th March 2009].
  2. Deakin University – Better Health Channel, March 2009. Tea leaves & health [Online]. Available at http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Tea_leaves_and_health?OpenDocument  [Accessed 10th March 2009].
  3. Linus Pauling Institute: Micronutrient Research for Optimum Health, November 2002. Tea & chronic disease prevention [Online]. Available at http://lpi.oregonstate.edu/f-w02/tea.html [Accessed 11th March 2009].
  4. Lipton, 2005. Health Care Professionals [Online]. Available at http://www.lipton.com.au/health-care-professionals/health-care-professionals.asp [Accessed 15th March 2009].
  5. National Cancer Institute , June 2002. Tea & Cancer Prevention [Online]. Available at http://www.cancer.gov/newscenter/pressreleases/tea [Accessed 11th March 2009].
  6. Wikipedia - The free encyclopaedia, March 2009. Tea [Online]. Available at http://en.wikipedia.org/wiki/Tea [Accessed 10th March 2009].

 


Last updated 17 June 2009