The humble cup of tea
For those of you reading this while drinking a cup of tea I have good news — it might be one of the best things you do for your health today.
And I’m not directing this remark at those who are sipping on an exotic herbal brew — I mean anyone drinking a standard cup of builder’s tea.
We don’t tend to class an ordinary cuppa as a health food — but when you look at the evidence mounting up for tea’s many benefits, there is a credible argument that we should.
What really made the case for this was a review of 96 studies, which found that tea could potentially benefit 40 different areas of our health, reported the journal Molecular Nutrition & Food Research in 2019.
The review’s authors, from Sichuan University in China, looked at the research into standard tea — by which I mean black, green, white (which comes from young leaves and makes a pale brew) and oolong (which is somewhere between the green and black and is typically served with milk).
These all come from the same Camellia sinensis tea plant; the difference is in the processing and how long they are left to mix with the air.
After sifting through the data, the researchers concluded that drinking two to three cups a day is associated with better gut health and a reduced risk of heart disease, stroke and type 2 diabetes.
What’s more, tea drinkers also appeared to have a reduced risk of certain cancers, such as lung cancer, and there were benefits for bone health and cognitive function (i.e. brain power).
The health benefits of tea stem from the fact that it’s high in polyphenols — plant chemicals that our gut bacteria break down into a range of beneficial compounds that have an antioxidant effect in the body. In other words, they protect our cells and tissues from wear and tear and mop up potentially harmful substances circulating in our system.
Tea polyphenols are also thought to help lower ‘bad’ cholesterol by suppressing the amount made in the liver and increasing the amount excreted in poop.
They have also been shown to stimulate the production of nitric oxide, which dilates blood vessels and helps reduce blood pressure and the strain on the heart.
If that wasn’t enough, they also protect against inflammation, which is known to underpin not just diseases such as type 2 diabetes but signs of ageing, too.
While there are richer polyphenol sources — tea contains around 100mg per 100ml, whereas blackcurrants, for example, contain around 750mg per 100g and hazelnuts 495mg per 100g — tea is an easy way to get a good, regular intake.
And you don’t even need to buy costly teas to reap the benefits. Green tea is often marketed as the more health-giving cousin of our standard English breakfast version. But for every study showing green tea to be superior, another shows black tea is not much different.
For example, the review I mentioned earlier found that drinking black tea was linked with a reduced risk of dying from cancer but green tea wasn’t (although six cups of green tea a day was associated with a 21 per cent reduced risk of stomach cancer). It’s also possible that other dietary habits played a part.
Despite black tea and green tea providing similar amounts of antioxidants, green tea contains less caffeine. So if you are anxious or suffer from headaches (both of which can be exacerbated by caffeine), then green might be a better option.
Green tea is also higher in L‑theanine, a chemical known to have a relaxing effect on the brain — but because of its caffeine content, I wouldn’t suggest drinking it close to bedtime.
One downside of any tea is that it contains tannin, a compound which while having antioxidant properties, less appealingly binds to iron and makes it harder to absorb. So, if you take iron pills or are anaemic, then drink tea two hours before or after meals.
I switch to decaf tea after 12pm because otherwise I find it can interrupt my sleep — and later in the afternoon I switch to rooibos tea (also known as red bush), which is high in antioxidants but also naturally caffeine-free.
The other option is herbal tea. Strictly speaking these aren’t teas at all, as they are made from flowers, spices and roots rather than tea leaves. Most are caffeine-free but they don’t tend to provide the same antioxidant hit as standard tea.
And just be aware that some herbal teas interfere with medication (ginger can thin the blood and lower blood sugar levels, for example), so it’s worth checking with your pharmacist if you plan to drink more than a cup or so a day.
But what can the favourite herbal teas offer in terms of health benefits?
This is associated with combating morning sickness or nausea caused by cancer therapies, but studies suggest you need four cups of shop-bought ginger tea to have an effect. You can get a similar benefit from a single cup made using a teaspoon of grated fresh ginger in hot water.
If you have a history of miscarriage, it’s best to avoid large amounts — and always ask your GP if you have any concerns.
Containing compounds that have an anti-spasmodic effect, peppermint has been shown to relax the gut lining and release trapped air, making it good for those with irritable bowel syndrome, bloating or stomach cramps.
But for those badly affected I suggest a peppermint oil capsule rather than tea, as you’ll get a higher dose.
You can make your own tea with a few mint leaves in water.
Chamomile contains apigenin, an antioxidant that binds to certain brain cell receptors which, in turn, is thought to reduce insomnia.
One study found that women who had recently given birth who drank the tea for two weeks (one cup per evening) reported better sleep than those who didn’t, reported the Journal of Advanced Nursing in 2015.
There is promising evidence for the benefits of turmeric, and more specifically the active component curcumin, among those with ulcerative colitis (where the large intestine is inflamed). But most of the research on this is done with high-dose curcumin capsules.
Turmeric may also help with menopause-related hot flushes —but let it cool a bit as a steaming mugful will counter the benefit in the middle of a hot flush.
Don’t drink any tea scalding hot (aim for no hotter than 50c). That’s because research (albeit limited) has suggested very hot drinks might cause damage to cells in the oesophagus, which could make cancer more likely.
But otherwise, enjoy. That soothing tea break could be doing you more good than you realise.
Contact Dr Megan Rossi
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