A cup of good tea is utterly engrained in the culture of the United Kingdom. We use tea to start our day or break up our work. It soothes us in times of trouble and helps us to wind down before bed. Tea is now also becoming a health drink, with suggestions that it has benefits for digestion, sleep and weight loss. Let’s take a look at the contents of our favourite brew.
Although tea is now seen as a very British thing, the plant from which it comes is mainly found in the warmer parts of the world. The plant needs plenty of rain and to be in a frost-free environment. There are dozens of types of tea available in all kinds of flavours, strictly speaking the only ‘real’ tea is that made from the leaves of the tea plant, Camellia sinensis. Green tea is currently much in vogue, but both black and green types come from this one plant. The difference is in how the leaves are processed.
All tea leaves are withered after picking. Those destined for green tea are heated to stop them fermenting, rolled and then reheated. To make black tea, the withered leaves are rolled and crushed, then allowed to ferment. This produces the black colour. The leaves are then dried, sorted, blended and packed.
So what is in that very welcome cuppa? Here are some of the ingredients and their effects.
L-theanine: this chemical affects brain function, and seems to reduce stress although there is no absolute proof as yet. However this would account for the perceived calming properties of tea.
Caffeine: Weight for weight, tea contains more of the stimulant caffeine than coffee. However, because tea is made with only a small quantity of the leaves, for cups of the same size there is less caffeine in tea than in coffee. Caffeine is a stimulant which temporarily leaves humans feeling more awake and alert, but can have unwelcome side-effects. Like most things in life, it needs to be taken in moderation, so those whose tea consumption is measured in pints rather than cups may wish to look for an alternative. For a caffeine-free cup of tea, drinkers should switch to tea made from the leaves of the South African red bush plant (Aspalathus linearis), which is often sold as Rooibos or ‘bush tea’.
Antioxidants: antioxidants are known to protect cells from damage caused by compounds known as free radicals. There is some evidence that these chemicals may help to prevent cancer, although clinical trials have been inconclusive and are still ongoing. Tea contains antioxidant compounds known as flavonoids, whose action is further enhanced by a small quantity of milk. Some sources believe that too much milk inhibits the antioxidant properties of tea – the ideal percentage of milk is 2%-5% of the volume of tea.
Vitamins and minerals: tea contains small amounts of folic acid, B vitamins, calcium and zinc. A cup of tea has almost no calories and no fat content, although adding milk or sugar will obviously change this. Tea also has beneficial levels of manganese and potassium, and contains the fluoride that is proven to strengthen teeth.
Green tea is frequently promoted as a magical remedy for weight loss. This is cited because the caffeine in it acts as a stimulant, and some studies have also shown that it may slightly improve metabolic rate. The possible change is the equivalent to using about an extra 100 calories a day for a normal human diet of about 2000 calories. This is a tiny difference and will be overcome by eating a piece of fruit or a small biscuit. There are no other effects that are even remotely reproducible. The facts are that green tea does not burn fat, reduce fat gain or do much else apart from provide a pleasant drink . So green tea extract and gallons of green tea join all the other weight loss remedies in the category of ‘things that do not work’.
There are other brews that can be made from leaves – these are correctly called ‘infusions’ but are often referenced as ‘teas’. There is some evidence that peppermint tea helps digestion because it contains antispasmodic drugs. Camomile tea is a good end-of-day drink as the herb has a mild sedative effect – although it is not recommended for pregnant women as it can cause the uterus to contract. There are many other infusions available, as well as dozens of varieties and blends of ‘real’ tea.
Tea has fascinated mankind for centuries, and is part of our history. From the Chinese traders to the Boston tea party, from the tea-clipper races to the giant tea plantations that still supply us, tea is an essential part of our economy and our lifestyle. It does contain some essential nutrients, and as it can be refreshing and warming without adding extra calories it has a definite place in a healthy lifestyle.
Our favourite drink may not have proven powers, but happily there do seem to be some benefits and very few problems associated with tea. It certainly makes us happier – and that means that brewing up can only be good for our health.
by Kath Webb
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