The study showed that the risk of dementia was about 30 to 40 per cent lower among older computer users than non-user.
Researchers at the University of Western Australia undertook an eight-year study of more than 5000 men in Perth aged between 65 to 85.
"As the world's population ages, the number of people experiencing cognitive decline and dementia will increase to 50 million by 2025," Professor Osvaldo Almeida, research Director at the WA-affiliate, the Centre for Health and Ageing, said.
"But if our findings are correct, the increase in the number of cases of dementia over the next 40 years may not be as dramatic as is currently expected," said Almeida in a statement.
Almeida said previous studies showed that cognitively stimulating activities decreased the risk of dementia but there was little evidence on the likely effect of computer use over many years.
"So it got us thinking, with personal computer ownership on the increase, could it make a difference? We found that it did, and that there was a significant benefit," he said.
The researchers found that computer users were younger than non-users, had completed at least high school, had a more active social network and were less likely to show evidence of depression or poor physical health.
They found that the risk of dementia was about 30 to 40 per cent lower among older computer users than non-users and that their findings could not be attributed to age, education, social isolation, depression, overall health or cognitive impairment.
Older people should therefore be encouraged to embrace computer technology as long as they understand the dangers of prolonged physical inactivity and the many advantages of a balanced and healthy lifestyle, the authors write.
The research is part of Australia's longest-running longitudinal study of men's health and ageing. It has been following a group of more than 19,000 men since 1996.
The results were published in the journal 'PLoSOne'.
