Cole and colleagues at UCLA and the University of Chicago used DNA microarrays to survey the activity of all known human genes in white blood cells from 14 individuals in the Chicago Health, Aging, and Social Relations Study. Six participants scored in the top 15 percent of the UCLA Loneliness Scale, a widely used measure of loneliness that was developed in the 1970s; the others scored in the bottom 15 percent. The researchers found 209 gene transcripts (the first step in the making of a protein) were differentially expressed between the two groups, with 78 being overexpressed and 131 underexpressed. “Leukocyte (white blood cell) gene expression appears to be remodelled in chronically lonely individuals,” said. Cole.
Genes overexpressed in lonely individuals included many involved in immune system activation and inflammation. But interestingly, several other key gene sets were underexpressed, including those involved in antiviral responses and antibody production. “These findings provide molecular targets for our efforts to block the adverse health effects of social isolation,” said Cole.
“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.” In the future, he said, the transcriptional fingerprint they’ve identified might become useful as a ‘biomarker’ to monitor interventions designed to reduce the impact of loneliness on health.
An obvious follow-up would be to find a way to make a group of lonely people a lot less lonely and then see if their gene expression levels change.
It is already known that a person's social environment can affect their health, with those who are socially isolated suffering from higher all-cause mortality, and higher rates of cancer, infection and heart disease. Researchers are trying to determine whether these adverse health consequences result from of reduced social resources (e.g., physical or economic assistance) or from the biological impact of social isolation on the function of the human body. "What this study shows us," said lead author Dr. Steven Cole, of the University of California Los Angeles (UCLA) School of Medicine, "is that the biological impact of social isolation reaches down into some of our most basic internal processes - the activity of our genes."
Does some subgroup of isolated people have an immunity toward the effects of isolation? Do their genes express at levels similar to those of non-lonely people?
Also, why less immune activity in lonely people? Maybe that's an adaptation. If you aren't exposed to other people you are at lower risk of getting a disease from them. So maybe less immune response was needed in the past among lonely people. Though today with more urban environments even lonely people can frequently come into contact with others and therefore be at risk of getting infections.
|Share |||Randall Parker, 2007 September 12 10:57 PM Brain Emotions|