Image of older man with cane, sitting alone

Social isolation is tied to a 26% increased risk of dementia and loss of brain volume in areas linked to cognition, a long-term study finds. The results highlight the crucial role social connections may have in helping older adults remain healthy, investigators reported in the journal Neurology.

The study followed more than 460,000 older adults for nearly 12 years prior to the pandemic. Nine percent of participants reported being socially isolated and 6% reported feeling lonely. Overall, 4,998, or about 1.1%, developed dementia.

Loneliness was not strongly correlated with developing dementia. But when compared with their socially connected peers, those who reported social isolation were more likely to receive a dementia diagnosis. Those individuals also had reduced brain matter in regions tied to learning and thinking. The findings were adjusted for factors such as age, sex, socioeconomic status, lifestyle factors linked to health and conditions such as depression and loneliness.

Early signs

“Given the findings of this study, social isolation may be an early indicator of an increased risk of dementia,” theorized Jianfeng Feng, Ph.D., of Fudan University in Shanghai, China. 

With pandemic conditions cutting off many seniors’ social networks, “it’s more important than ever to identify people who are socially isolated and provide resources to help them make connections in their community,” he said in a statement.

Natural loss with aging

Adults are known to gradually lose brain volume with age, with the volume and/or weight declining at a rate of around 5% per decade after age 40, according to prior research. Older adults also are more likely to experience other brain diseases, including stroke and white matter lesions. It is widely accepted by experts that aiming for a healthy mental and physical life may help slow, and in some cases prevent, those changes.

The study was published online in the journal Neurology.