Tea, the perfect health drink

There are so many reasons to have a cup of tea.

There are so many reasons to have a cup of tea.

Published Oct 9, 2015

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London - Growing up, tea drinking was reserved for my grandmother’s visits.

Making it followed a strict ritual.

Take scalding hot water. Warm the tea pot. Add one spoon of tea leaves for each person and one for the pot. Cover with a tea cosy. Turn the pot three times to the left, three to the right, then three to the left. Leave to brew. Warm the cups; milk in first, pour through a tea strainer.

My grandmother could taste any attempt you made to shortcut the process.

By world standards South Africa ranks 55th, tied with Australia, for tea consumption, compared with the US at 69, New Zealand 45 and the UK, number five. Turkey takes the number one spot, consuming more than 10 times the per capita intake of Australians.

 

Tea and survival

Around the world, tea is the most common drink after water. Popularity increased in the 1800s because the practice of boiling water to make the tea meant water-borne pathogens like cholera and typhoid would be killed, making it safer to drink.

Tea comes from the leaves and buds of the plant Camellia sinensis. Black tea, green tea, white tea, and oolong varieties all come from the same plant, but are processed into dried leaves differently.

Science has muscled in on our tea drinking habits and started to unravel what makes us love our “cuppa”. There is a large group of bioactive components in tea called polyphenols, which include catechins and tannins.

Concentrations of these compounds vary depending on how you make the tea.

Catechins have anti-oxidant properties and are most abundant in green tea. Tannins, which inhibit non-haem iron absorption in the gut, are most abundant in black tea. So if you have iron deficiency, avoid drinking tea with meals. But if you have the excessive iron storage condition haemochromatosis, drinking tea with meals will help reduce iron absorption.

 

Tea and your brain

Components of tea that can boost brain activity include caffeine, catechins and the amino acid, L-theanine.

In a systematic review of the effects of tea on mood and cognitive function, the combination of L-theanine and caffeine was shown to increase alertness and attention-switching accuracy up to two hours after consumption. The researchers also found small enhancements in accuracy of visual and auditory attention.

Preliminary evidence also suggests catechins may have a calming effect during the second hour post-cuppa.

At this stage however, there is no clear evidence that drinking tea will protect people from developing dementia.

 

Tea and weight loss

There has been a lot of interest in whether tea, particularly green tea, can increase energy expenditure and help with weight loss.

Two Dutch meta-analyses have examined the evidence in studies comparing catechin-plus-caffeine mixtures versus caffeine-only supplements on energy expenditure and fat oxidation (breaking down fat). They found that compared with placebo and caffeine-only groups, people who had catechin-plus-caffeine mixtures were more likely to break down fat.

They also evaluated whether green tea could improve body weight regulation. Their meta-analysis found the group consuming catechins from green tea had a 1.3 kilogram greater weight loss and were more likely to maintain this loss; although there were some differences based on ethnicity and usual caffeine intake.

 

Tea and diabetes

Last year, a pooled analysis of 12 cohort studies compared tea drinking with risk of type 2 diabetes. Researchers found that among those who drank three to four or more cups per day there was a 16 percent lower risk of developing type 2 diabetes, compared with those who usually drank just one or no cups of tea.

But when they drilled down into the studies, the lower risk was only found in women and those of Asian ethnicity.

 

 

Tea and heart disease

A Cochrane review evaluated 11 randomised controlled trials that ran for at least three months and were aimed at preventing heart disease in healthy adults or those at high risk of heart disease.

Pooled results showed that both green tea and black tea significantly reduced blood pressure, with black tea lowering LDL-cholesterol and green tea lowering total cholesterol.

Meanwhile, for a host of other reasons it seems that my grandmother was right: a good brew does more than than just warm you up (or cool you down). So put the kettle on, get out your best tea cups, create your own tea-making ritual, gather the clan and relax with a cuppa.

The Conversation

l Clare Collins is a Professor in Nutrition and Dietetics at the University of Newcastle

 

Which teas are best for your health?

Jasmine tea

The wonderfully aromatic jasmine tea has been used in China for its medicinal qualities for centuries and in some ancient Chinese manuscripts, jasmine was used as an aphrodisiac and fertility booster.

There may be some truth to the legends as studies have shown that jasmine tea has strong aromatherapy qualities that are good for the body during pregnancy.

Full of antioxidants, this tea can help to boost the immune system, may help in the fight against cancer, provide relief to gastrointestinal disorders, and aid in lowering cholesterol and reducing high blood pressure.

It does, however, contain caffeine (although not in the same concentrations as breakfast tea or coffee) so should be consumed in moderation, and avoided at night to help promote good sleep.

 

Nettle tea

Nettle tea benefits women throughout their pregnancy, but also helps to promote fertility.

Full of goodness, nettle leaves contain vitamins A, C, D and K.

By sipping this tea, women also boost their levels of calcium, potassium, iron, and sulphur. It is also good for foetal health.

This tea is rich in minerals such as calcium and magnesium and can help with allergies such as hay fever.

Cooled nettle tea can be applied to the skin to help alleviate dry and itchy skin.

 

Mint tea

Rejuvenating and refreshing mint tea is a wonderful relaxant. The health benefits are much stronger if you are able to use fresh mint leaves.

Never a symptom to be underrated, stress can reduce fertility and even stop ovulation altogether for short periods of time, so any stress-reliever is good for those who are trying to conceive.

Like red raspberry leaf tea, mint tea can also reduce pregnancy nausea.

Another useful property is that it contains vitamins A, C, and B12 as well as the essential pregnancy B vitamin folate, which is the natural form of folic acid.

Mint tea is commonly used to aid digestion, hence it is traditionally consumed after meals, as it can soothe an upset stomach and indigestion.

It can help with coughs and colds by loosening congestion, and easing a sore throat, as well as combating bad breath.

Lizzie Parry, Daily Mail

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