A diet of fruits and vegetables loaded with anti-oxidants - such as polyphenols in green tea, lycopene in tomatoes, resveratol in red grapes nad beta-carotene in carrots - protects the body against oxidative stress, one of the major contributors to biological ageing.

Apart from their known beneficial effects on cancer and heart disease and their ability to retard age-related degeneration, some anti-oxidant rich foods are now believed to actually reverse age related neuronal and behavioural decline.

Fresh spinach and strawberries (frozen would do, but not tinned), apart from the new wonder fruit, blueberries, taken over a period of time, repair the damage ageing does to the brain.

A cheap and effective anti-oxidant in Vitamin E. Found in whole grains and wheat germ, nuts and vegetable oils, Vitamin E protects the body tissues and helps the blood circulate freely. Older people with high levels of Vitamin E are less likely to experience a decline in intellectual functions that usually accompanies ageing.

Black currants, tomatoes and citrus fruits such as oranges and lemon are rich in Vitamin C, another good anti-oxidant. But a cup of green tea a day can work wonders, as it has 20 times the radical quenching abilities of Vitamin E and 500 times that of Vitamin C.

How anti-oxidants work is simple. The body's metabolism releases oxygen free radicals, DNA damaging toxic agents which can harm the cell membrane, often killing the cell in the process. Anti-oxidants help to neutralise and subdue these oxygen free radicals. Added to this, anti-oxidants also aids neuronal communication - the ability of one neuron to communicate with one another - which improves short-term memory.

``Indian anyway have a diet rich in anti-oxidants because most people eat natural and fresh food, unlike in West where most of the anti-oxidant qualities of a foodstuff are lost when it is tinned,'' says Dr Madhuri Behari, professor of Neurology at the All India Institute ofMedical Sciences (AIIMS), New Delhi.

Specialising in disorders usually associated with ageing like Alzheimer's disease and dementia, Behari says a good diet is the major reason why surveys at the Vallabhgarh Primary Health Centre in Haryana have shown that the incidence of such diseases is significantly lower in India than other parts of the world.

``Fresh and natural food is best, and that is why people in urban areas should be encouraged to give up processed food and go back to atta (wholewheat flour) and fresh fruits,'' she says.

Agrees, M C Maheshwari, head of the neurology department at AIIMS: ``Synthetic anti-oxidants are available, but there is nothing like fresh fruits and vegetables to make you sprightly at 70. I suspect even memory-enhancers that are flooding the market are nothing more than anti-oxidants that boost memory temporarily.''

Many ayurvedic medicines also claim to have anti-oxidative qualities, but since these claims are not backed by research, their effectiveness is suspected.