SOUL/BODY: Loneliness Connects to Genes for Immune System

by Carol Schuck Scheiber

In the first study of its kind, University of California–Los Angeles (UCLA) researchers recently found that feelings of isolation are linked to alterations in the activity of genes that drive inflammation, the body’s first immune response — providing a molecular framework for understanding why social factors are linked to an increased risk of heart disease, viral infections, and cancer.

“What this study shows is that the biological impact of social isolation reaches down into some of our most basic internal processes — the activity of our genes,” said Steve Cole, an associate professor of medicine at UCLA’s David Geffen School of Medicine. “We found that changes in immune cell gene expression were specifically linked to the subjective experience of social distance. The differences we observed were independent of other known risk factors, such as health status, age, weight, and medication use. The changes were even independent of the objective size of a person’s social network.” That the size of a person’s network is unimportant, said Cole, means that “what counts at the level of gene expression isn’t how many people you know, it’s how many people you feel really close to over time.”

The study involved 14 people — 6 in the top 15 percent of the UCLA Loneliness Scale, a measure of loneliness used since the 1970s; the other 8 scored in the bottom 15 percent of the Loneliness Scale. Researchers found that 209 gene transcripts were differentially expressed between the 2 groups, with 78 being over-expressed and 131 under-expressed. The genes of chronically lonely people showed over-expression in immune system activation (such as inflammation) but under-expression in antiviral responses and antibody production.

The scientists speculate that these specific genetic transcripts could be useful biomarkers to monitor interventions aimed at reducing the impact of loneliness on health. The research may also have an effect on the kinds of treatments used for those who suffer social isolation.