SINGAPORE - Men, are you old and alone? Go out and have fun to give your brain a boost.

Single old men need to socialise, to ward offdiseases which affect the brain such as dementia, according to a recent study by the National University of Singapore.

Men who had never married had the highest risk - they had a more than six-fold risk of getting dementia, compared to those who were still married. Widowers did not fare much better - they had five times the risk.

The study looked at about 2,500 Singapore Chinese aged 55 and above in Geylang. Most were from a lower-income group, living in one-to-three room flats.

They were given a cognitive test which included tasks like simple mathematics, saying the name of the Prime Minister and naming objects.

The differences were much more stark in men - the researchers did not see any significant differences between married and single women.

Said Associate Professor Ng Tze Pin of the university's Yong Loo Lin School of Medicine: "This may be because women socialise more. They have help-seeking behaviour when it comes to health or loneliness.

"Men may like to keep to themselves."

Explaining the cushioning effects of marriage, he added: "Marriage may introduce more social engagement and reduce the psychological stress of loneliness."

Among about 570 single and widowed persons surveyed, those who socialised more were also associated with a lower risk of cognitive impairment. Those who were more active socially halved their risk, compared to the more isolated participants.

"Go out and socialise, volunteer or participate in community," was Prof Ng's advice.The researchers intend to expand the study other areas of Singapore and possibly include more language groups. The effort is part of the Singapore Longitudinal Ageing Study, which hopes to track the welfare of the country's ageing population.