A fascinating new study in Genome Biology suggests that loneliness may be correlated to changes in gene expression. A lot of literature correlated lack of social contact (loneliness) with detrimental health effects. This is the first study of its kind that looks at genome wide expression in such a population.
Social Isolation and Health Risks
A variety of theories explaining the correlation between social isolation and health risks have been put forward. One suggests that the social isolation leads to lack of medical care and support. This idea suggests that not having someone who insists you go to the doctor or runs out to get your pills leads to lack of self care and that evolves into health problems. Depression has certainly been linked to lack of self care.
Another theory suggests that there is a direct effect of isolation on the body itself. A third theory suggests that there is a biological reason for a person being isolated and this may also correlate with susceptibility to disease. A depressed individual, for instance may become socially isolated and the genetic trait that might have led to depression may also affect the body defences to disease.
Changes in genes related to the body's defences
This study looked at gene expression in those that were subjectively chronically isolated versus those that were not. The "gene chip" allows an investigator to monitor the level of gene expression in a large number of genes in a tissue. Over 200 genes were differentially expressed i.e. their level of expression changed between the two study groups. Changes in inflammatory genes were strongly correlated with social isolation.
Perception is key
These changes were correlated with a population that were subjectively isolated and did not relate to the size of their actual social network. How they perceived their social network was most important. This may have implications for treatment. Changing a person's perception of their isolation in society might change their susceptibility to disease.
Stress did not appear to be a factor
Changes in the immune system have been observed previously to correlate with stress but the changes in this study did not correlate with cortisol levels which has been thought to be the immune modulator associated with stress.
Gene expression "fingerprint"
This study then shows that those who perceive themselves to be chronically isolated appear to have a gene expression "fingerprint" and part of this gene expression fingerprint is involved in inflammatory pathways. As social creatures, humans may well gain health benefits from the integrated society we live in.
Divorce and social isolation
This study may have implications for divorced individuals who do not adapt well to the change in social structure that divorce brings. If they perceive themselves as socially isolated after divorce, this may lead to health issues later on in life. Social reintegration or at least a change in the person's thoughts about social integration may be quite an important part of divorce recovery. If you have issues with loneliness after divorce, you should take this seriously and address these issues with a professional.