Socially isolated people are 26% more likely than individuals with more active social connections to develop dementia later in life. The corresponding study was published in Neurology.
Professor Edmund Rolls, a neuroscientist from the University of Warwick Department of Computer Science, and one of the study's authors, said: "There is a difference between social isolation, which is an objective state of low social connections, and loneliness, which is subjectively perceived social isolation.
"Both have risks to health but, using the extensive multi-modal data set from the UK Biobank, and working in a multidisciplinary way linking computational sciences and neuroscience, we have been able to show that it is social isolation, rather than the feeling of loneliness, which is an independent risk factor for later dementia. This means it can be used as a predictor or biomarker for dementia in the UK," he continued.
For the study, the researchers analyzed health records from the UK Biobank involving neuroimaging data alongside demographic, lifestyle, and mental health information from over 30,000 people in the UK.
After adjusting for risk factors, including socioeconomic status, chronic illness, and depression, the researchers found that socially-isolated individuals tend to have a 26% higher likelihood of developing dementia than non-socially-isolated individuals.
They also found that loneliness was linked to later dementia, however, 75% of this association could be accounted for by depression. This led the researchers to conclude that relative to subjective feelings of loneliness, social isolation is an independent risk factor for dementia later on in life.
The researchers noted that given increasing rates of social isolation and loneliness in recent decades, environmental methods for reducing dementia rates in older adults are crucial. They recommend governments and communities take action to ensure that older individuals communicate and interact with others on a regular basis.