Drinking three cups of tea a day can keep you mentally alert in old age

It's the national drink that millions of us turn to when we need a pick-me-up.
But tea does far more than just help to wake us up. Scientists say the traditional cuppa can keep the mind sharp into old age. And the benefits of drinking as little as one to three cups a day in staving off mental decline are especially pronounced among women.
In one study, of almost 1,500 men and women in Singapore, drinking more than four cups a day cut the odds of memory failing by three-quarters.  Even just one to three cups of Ceylon tea a day had an effect, cutting the odds of cognitive decline by 43 per cent.
It is thought compounds in tea may protect against the poisons that ravage the brain in Alzheimer’s.
Possibilities include theanine, a plant chemical found only in tea and in mushrooms.
Experts in the US analysed several studies on the effect of caffeinated drinks on memory and mental alertness. The thousands of men and women who took part logged how often they drank tea or coffee and did a memory test that is used in the initial stages of diagnosing Alzheimer’s disease.