According to a study led by a professor at the University of Cambridge Barbara Sahakyan (Barbara Sahakian), social isolation in older adults increases the risk of dementia, leading to cognitive decline and decreased gray matter volume in areas of the brain associated with learning and memory.
The researchers looked at data from 462,619 people from the UK Biobank. The average age was 57 years. Participants were asked whether they lived alone, visited friends or family at least once a month, and participated in social activities. Those who answered “no” to at least two questions were considered socially isolated.
To “measure” loneliness, participants were asked how often they felt lonely and how often they confided in other people. Those who answered “yes” to the first question and “less than once a month” to the second were considered lonely.
The researchers also collected other information, MRI data, and tests to assess cognitive function.
At baseline, 9% of participants reported being socially isolated and 6% reported feeling lonely. Compared to the control sample, isolated and lonely people had worse cognitive function.
After 11 years of follow-up, 4998 participants developed dementia. The incidence was 26% higher among those who reported being socially isolated.
Subgroup analyzes showed that social isolation was significant only in older participants (mean age 64.6 years; adjusted hazard ratio 1.28) and with depressive symptoms (hazard ratio 1.27).
A follow-up MRI 9 years after the start of the study also showed less gray matter volume in areas of the brain associated with learning and memory in older adults who felt socially isolated.
According to Professor Sahakyan, visiting public places, social activities, establishing friendships through hobbies and clubs help older people maintain social activity and thus reduce their risk of developing dementia.