Why a cuppa is tea-rrific for your health

We drink a staggering 165 million mugs of tea every day, but did you know it could help you live longer, keep your brain sharp and make men more fertile? JAMES MOORE brews up the body of evidence

BRAIN: A study from the National University of Singapore revealed that regularly drinking tea can reduce the risk of cognitive decline.

In fact, scientists say it could halve the likelihood of dementia because of antioxidant-containing polyphenols.

Tea contains an amino acid, L-theanine, which increases feelings of relaxation, and studies show it lowers stress hormone levels and reduces depression. Substances in the drink also appear to boost creativity and problem-solving.

Despite containing caffeine, recent research suggests drinking tea within four hours of bed does not affect sleep while having a camomile tea helps. EYES: Your cuppa could protect your peepers. A study published in the British Journal of Ophthalmology found enjoying just one cup a day could lead to a 74% reduction in your risk of developing glaucoma, one of the main causes of blindness. TEETH: Tea plants absorb fluoride from soil and it helps protect against tooth decay. Experts say it can boost defences by as much as 40%.

A study published in the British Nutrition Foundation’s Nutrition Bulletin claimed drinking at least three cups of black or green tea a day reduces harmful bacteria in the mouth. And an adult clinical trial in Japan found plant compounds in normal black tea – known as theaflavins – killed off oral bacteria linked with tooth and gum disease.

HEART: A Dutch study found those who drank three to six cups of tea a day had a 45% lower risk of dying from heart disease compared with people who had less than one.

The benefit is believed to come from antioxidants called flavonoids. It also helps lower blood pressure – a key risk factor for heart disease and stroke. Black tea can have a 10% effect while green tea reduces hypertension risk by 46%. DIABETES: Drinking at least three cups of tea a day has been associated with a reduced risk of type 2 diabetes. This is because it improves your insulin sensitivity. Once again, the experts believe it is the polyphenols in black, green and oolong teas that bring the benefits.

It’s worth noting, however, that research suggests the benefits are best when you drink your tea without milk. An American study in 2002 found that addition of the white stuff actually decreased your cuppa’s insulin-sensitising effects.

JOINTS AND BONES: The anti-inflammatory effects of compounds in tea can ease joint pain, with green tea in particular helping to prevent osteoarthritis, say researchers at the University of Sheffield.

And a study reported in the American Journal of Clinical Nutrition found drinking just three cups of our usual black tea protects against osteoporosis.

IMMUNE BOOSTING: Tea could help boost your immune system. A study published in the journal Nutrients suggests tea drinkers have more friendly gut bacteria.

A University of California study found English breakfast tea increases levels of metabolism-boosting bacteria, aiding weight loss and other research has shown rooibos tea reduces fat levels in cells.

AND THE REST: Green tea has been found to help protect your liver and has also been identified as having the ability to boost sperm production.

An Australian study found that lifelong tea-drinking women were less likely to get ovarian cancer and another found that drinking three cups of tea a day cuts the risk of breast cancer by 37%.