Discoveries

July 22, 2022

Home Alone

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Social isolation doesn’t only affect a person’s emotional state but also their brain’s structure and cognition, according to a new study.

A research team recently analyzed how loneliness and social isolation affect the gray matter, the regions in the outer layer of the brain that consists of neurons.

Researchers wrote in the Conversation that previous studies have shown that brain areas associated with social interactions are strongly linked to networks that support cognition. These include networks that help us to focus and memorize and those regulating emotions.

For their paper, the team investigated data from almost 500,000 people with a mean age of 57 from the United Kingdom’s Biobank. They categorized socially isolated people as individuals who lived alone and had social contact less than once a month.

The study also analyzed neuroimaging scans from nearly 32,000 people, which showed that isolated individuals had a lower volume of gray matter and poorer cognition, including in memory and reaction time.

Researchers spotted a connection between reduced gray matter volumes and particular genetic pathways associated with Alzheimer’s disease. When they contacted participants 12 years later for follow-up, scientists found that those who were socially isolated but not feeling lonely had a 26 percent higher risk of dementia.

While they acknowledged that further research is needed on social isolation, the authors cautioned that if people don’t engage in social interactions to shore up their cognitive skills, these might diminish over time.

They suggest that individuals should take up activities that keep the brain active, such as learning a language or a musical instrument. But they also emphasized that health officials could help in tackling social isolation by determining who is isolated and arranging social activities to help these individuals.

This story originally appeared in the July 22, 2022 newsletter, The Trains To Nowhere.