How diet and exercise can keep both the heart and mind active in later life

A simpler recipe for staying sharp in old age has been uncovered by scientists.

The four key factors involved in preventing mental decline were found to be exercise, education, social activity and not smoking.

Researchers carried out a series of memory and mental tests on 2,500 men and women aged 70 to 79 over a period of eight years.

Just over half the participants showed a normal rate of agerelated decline while 16 per cent suffered a major reduction in their mental faculties. 

Exercise is one of four key factors in preventing to prevent mental decline in elderly people, scientists have found

However, 30 per cent of the study volunteers remained unchanged and in some cases even showed an improvement in performance over the years.

The researchers then examined what lifestyle factors stood out among the people who were able to remain quick-witted in old age.

The study, published in the journal Neurology, revealed that those who exercised moderately or vigorously at least once a week were 30 per cent more likely to 'stay sharp' than people who did not.

Individuals with a good education were nearly three times more likely to maintain their mental faculties than those with less education.

Non-smokers were nearly twice as likely to remain mentally fit than smokers.

And people who were socially active - either by working or volunteering, or by living with someone - were 24 per cent more likely to avoid mental deterioration in later life.

'Some of these factors such as exercise and smoking are behaviours that people can change,' said study leader Dr Alexandra Fiocco, from the University of California at San Francisco.

'These results will also help us understand the mechanisms that are involved in successful ageing.'