Higher social isolation causes faster cognitive decline, regardless of whether or not people identify as lonely, according to a recent study. Social isolation is objectively measured as, for example, sociability, membership in community organizations, and religious participation, whereas loneliness is a subjective report of how often people feel lonely, researchers say. While social isolation and loneliness are often thought of as associated, they appear to have independent effects on cognitive function.

Researchers analyzed data from the US Health and Retirement study, looking at 137,653 cognitive function tests taken between 2004 and 2018 by over 30,000 individuals. They found a consistent pattern of social isolation having a detrimental direct causal effect on cognitive function, with only 6% of this effect operating through loneliness.

Reducing social isolation had a protective effect on cognitive function for all subpopulations regardless of gender, race, ethnicity and educational level. Further analysis showed that targeting social isolation among those living alone may be one public health strategy for protecting against cognitive decline.

"Around the holidays, many of us think a lot about how important it is to be surrounded by family and friends, [and] we're reminded that social engagement is good for our mental health. This research shows that it's also important for our cognitive health," said lead author Jo Hale, PhD, of the University of St. Andrews, Scotland. "As Alzheimer's is a leading cause of death for older adults in the UK/US, ... allowing for regular social interaction, especially for those who mayn't have family or friends nearby, should be a public health priority."

To read the abstract of the study, published in The Journals of Gerontology: Series B, gbaf254, click here