While many of us seem to run to coffee for our daily dose of goodness, tea happens to be the second most popular beverage consumed worldwide—beat only by water.
Whether you prefer it green, black or any shade between—with sugar, spice or that perfect dash of milk—tea is a BIG part of many cultures and has developed so much that there are countless types of tea, and just as many ways to drink it.
Tea is believed to have originated in China for medicinal purposes and later spread as a drink of recreation, eventually reaching Europe and the rest of the world. The “cuppa” is especially beloved by Brits and Aussies alike.
According to Roy Morgan research, in 2016, 50 per cent of Australians were drinking one or more cups of tea a week, with an average of 9.5 cups of tea per week. Interestingly more women (55 per cent) are drinking tea than men (45 per cent). And unsurprisingly, 65 per cent of people over the age of 65 are consuming more tea (up to 11 cups a week) than the youngins’ (who are probably drinking coffee).
Where does tea come from?
What most people don’t know is that all tea comes from the plant Camellia sinensis—but it is the way the leaves are processed that gives us the variety of teas, and their specific colour, scent and taste. The top producers of tea are China, India, Kenya and Sri Lanka. It is usually mass-produced in plantations, and once the leaves are picked, oxidation begins. Oxidation determines the type and quality of tea during the processing stage.
In chemistry terms, oxidation occurs when a substance loses electrons. It is also what happens when you cut up fruit, such as an apple, and it turns brown over time due to the reaction with oxygen in the air. It may not sound like a good thing but, in terms of processing tea, it is vital!
There are four main types of tea: green, black, oolong and white. They all look and taste different due to the level of oxidation they are exposed to.
For black tea, once the leaves are picked, they are left to wither so they lose moisture. These are then rolled or cut to release the last of the moisture and then spread out and left to oxidise. At first, the tea leaves are green but, as oxygen in the air reacts with the cells in the leaves, they start to turn brown or black in colour. They are then dried, and the colour can further darken, until they are eventually sorted by size and grade. Green tea however, once picked and withered, is steamed to stop the oxidation process. Oolong tea sits between green and black tea, it is partially oxidised. White tea is rare, and its leaves are only picked twice a year when the buds are not yet fully opened, like green tea it is steamed before oxidation can take place which gives it a smooth, less grassy flavour.
Some herbal “teas” can have added scent or flavour. Most people associate these “infusions” as tea, when in reality, they are not from the tea plant at all! They are just dried fruits and spices in hot water. For example, Rooibos teas come from the plant Aspalthus linearis and chamomile and mint teas are just infusions of the chamomile flower and mint leaves with hot water to make “herbal infusions”.
What’s in the leaves?
Tea is composed of amino acids, vitamins and minerals. However, its most active ingredients are antioxidants and caffeine.
Just like tea leaves and apples, molecules in our body are prone to oxidation, where they lose an electron and become unstable free radicals which can damage our cells and potentially lead to cancer or heart disease. Antioxidants are chemicals which counteract the oxidative process and support healthy metabolism, these are usually found in fruits and veggies. Tea contains a class of polyphenols known as flavonoids which are effective antioxidants. Specifically, catechins in green tea and thearubigins and theaflavins in black tea. Tea also contains caffeine which is a stimulant that increases alertness, decreases drowsines and contributes to the “I need to pee” feeling.
What are the benefits?
So what makes tea beneficial? Studies have shown that tea consumption can help improve cholesterol levels, vascular function, blood pressure, atherosclerosis, obesity, type two diabetes and even combat some cancers.
Although the exact mechanism responsible remains unclear, it has been thought that the flavonoids in tea increase the production of nitric oxide within blood vessel walls. This helps our blood vessels to dilate so that blood flows smoothly and with less resistance (think about your typical garden hose, any blockages in the hose and kinks interrupts the water flow). A recent study has shown an improvement in vascular function after a mere one month of consuming black tea. Another study, which recorded 24 hour ambulatory blood pressure of tea drinkers, found a decrease in blood pressure of 2-3 mmHg over six months.
Tea has also been linked to improving insulin sensitivity and lowered blood glucose in healthy people by affecting specific glucose receptors in body cells, and controlling cancer development through its anti-inflammatory effect.
With places like T2 and various cafes and bubble tea joints (I’m a Cha Time gal myself) popping up and offering many varieties of tea and increasing the general public’s interest in tea and tea culture, it is worthwhile to know what you are drinking!
So, with all that in mind, go make yourself a cuppa and stop to think that perhaps, this wonderful steaming mug of goodness, contains the cure to some of our worst diseases.
And that’s the tea!
Full disclosure: although many studies have found a link between drinking tea and improvement in certain health conditions, more clinical studies are required to determine its full effect.