Academics at University College London found that someone who saw friends almost daily at the age of 60 was 12 per cent less likely to develop dementia than someone who only saw one or two friends every couple of months.
Having an active social life “at any age may well have a similar impact on reducing dementia risk”, according to the researchers.
Socialising promotes the use of memory and language, which could help minimise the effect of dementia, according to Professor Gill Livingston, a senior author of the report.
She added: “People who are socially engaged are exercising cognitive skills such as memory and language, which may help them to develop cognitive reserve – while it may not stop their brains from changing, cognitive reserve could help people cope better with the effects of age and delay any symptoms of dementia.
“Spending more time with friends could also be good for mental wellbeing, and may correlate with being physically active, both of which can also reduce the risk of developing dementia.”
While previous studies have found a link between social contact and dementia risk, the new study, published in the PLOS Medicinejournal, provides the “most robust evidence to date” to support the theory, according to a university statement.
Researchers used data from a study tracking more than 10,000 people from 1985.
Participants were asked on six occasions about the frequency with which they socialised with friends and relatives.
Dr Andrew Sommerlad, the study’s lead author, said dementia poses a “major global health challenge”, with one million people expected to have the disease in the UK by 2021.
He added: “This finding could feed into strategies to reduce everyone’s risk of developing dementia, adding yet another reason to promote connected communities and find ways to reduce isolation and loneliness.”
Dr Kalpa Kharicha, head of innovation, policy and research for the Campaign to End Loneliness, said: “We need more awareness of the benefits that social wellbeing and connectedness can have to tackle social isolation, loneliness and reduce dementia risk.”
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