Coffee drinkers will be clinking mugs in a toast to new research suggesting that just two strong cups of the black stuff a day can reverse the effects of Alzheimer's disease. Dr Gary Arendash of the University of Florida showed that coffee not only helped to reverse symptoms in mice but also staved off production in the brain of abnormal protein plaques, which are the hallmark of Alzheimer's.

In the UK the Alzheimer's Society is anxious not to suggest that everyone develop a caffeine habit but says that if further research confirms its benefits, coffee could become part of a lifestyle prevention plan for the disease.

So what else could be in the armoury? Researchers at Columbia University in New York recently found that a Mediterranean-style diet high in fish oil and vegetables prevented people with mild memory loss from getting full-blown dementia, and also seemed to prevent memory decline in the general population. Blueberries, kale and broccoli seem particularly helpful.

Smoking is repeatedly shown to dull the brain's efficiency, so that's another reason to quit, but some studies suggest that moderate alcohol intake (one or two drinks a day) can be protective.

Staying fit seems to help, too. A study of more than 2,200 Japanese-American men between the ages of 71 and 93 found that those who were sedentary or walked under a quarter of a mile per day were nearly twice as likely to develop dementia as those who covered two miles or more a day. And a report in the New England Journal of Medicine found that regular dancing of any sort reduced the risk of the disease.

Being bilingual or learning languages preserves brain function and lowers the risk of dementia, and the "use it or lose it" theory also has proven benefits. One study of 400 pensioners in New York showed their risk of neural decline was halved through activities such as sudoku, crosswords, visiting museums and playing a musical instrument.

It's better still if you can complete those puzzles with a spouse. Being married means you are at half the risk of getting dementia compared with singletons, Swedish researchers reported this month. But maintaining that marital status quo is essential: the same study found that divorce in mid-life will increase the risk three-fold.