UCLA researchers have identified a pattern of gene expression in immune cells from people who experience chronically high levels of loneliness.
Their study, published in the September 13, 2007 issue of Genome Biology, provides a molecular framework for understanding why social factors are linked to an increased risk of heart disease, viral infections, cancer and death. "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," says Steve Cole, an associate professor of medicine in the Division of Hematology and Oncology at the David Geffen School of Medicine at UCLA and a member of the Cousins Center for Psychoneuroimmunology.
Cole and his associates used DNA microarrays to survey the activity of genes in the white blood cells of 14 individuals. Six participants scored in the top 15 percent of the UCLA Loneliness Scale, a widely used measure, while the others scored in the bottom 15 percent. A total of 209 gene transcripts, the first step in the making of a protein, were differentially expressed between the two groups, with 78 overexpressed and 131 underexpressed.
"We found that what counts at the level of gene expression is not how many people you know; it's how many you feel really close to over time," said Cole. Many of the genes overexpressed in lonely individuals are involved in immune system activation and inflammation, while underexpressed genes included those related to antiviral responses and antibody production. Says Cole, "These findings provide molecular targets for our efforts to block the adverse health effects of social isolation."
Source: UCLA news release of September 13, 2007