Article in the Telegraph
"Scientists found those who drank two or three cups of black tea a day were less than half as likely to exhibit early signs of dementia as those who never or rarely drank it.
But drinking coffee had no protective effect on the brain, the study found.
The scientists concluded that it was not the caffeine in tea that had a beneficial effect, but compounds called polyphenols.
Previous studies have already suggested polyphenols in green tea can protect against dementia and Alzheimer's, which affect an estimated 750,000 in Britain today.
That number is set to double over the next 40 years as Britain's population ages.
But this is the first time a comparative study has been made on the protective effects of black tea, by far the most popular variety drunk here.
Britons drink 168 million cups of black tea a day, although most of us put a splash of milk in it.
You can also reduce your risk of dementia by cutting down on salt and salty food.