Regularly using a computer - more than many other social activities - could help reduce the risk of memory and thinking problems that lead to dementia, according to a new study.

The study, conducted by the Mayo Clinic in Arizona, found that those aged 70 years and older who used a computer once a week or more were 42% less likely to develop memory and thinking problems.

1,929 people aged over 70 were involved in the study. At the start of the process they were classified as having ‘normal memory and thinking’ abilities. The study followed them until they developed mild cognitive impairment or remained problem-free - on average this was four years per person.

Mild cognitive impairment was found in 193 out of 1,077 people (17.9%) in the group who used a computer, it was found in 263 out of 852 people (30.9%) in the group that did not report computer use.

Looking at other hobbies, people who read magazines were 30% less likely to develop memory problems, those who knitted were 16% less likely and those who played games 14% less likely.

[Related story: 11 things you should really know about dementia]

People who take part in social activities are 23% less likely to develop memory problems. 20% of people in the social activities group developed problems, in contrast to 26% in the group that didn’t take part in social activities.

Janina Krell-Roesch PhD, from the Mayo Clinic, says the results show how important it is to keep the mind active: "While this study only shows association, not cause and effect, as people age, they may want to consider participating in activities like these because they may keep a mind healthier, longer."

Claire Walton, from the Alzheimer’s Society, says there’s increasing evidence of the importance of staying mentally active as we get older: “This could include activities such as regularly doing puzzles, trying out arts and crafts or joining a book group. Although this research is only preliminary, it should be encouraging to today’s generation of silver surfers that using a computer might also help to keep memory sharp.

“Dementia, however, is a complex condition and we do not know what effect these activities have on the risk of developing it. Currently, the best evidence for reducing your risk of dementia is to exercise regularly, avoid smoking and eat a healthy, balanced diet.”

The study will be presented at the American Academy of Neurology’s annual meeting in Vancouver on April 15.

For advice on dementia, including symptoms and advice on caring for a sufferer, visit the Alzheimer’s Society website.