Social genomics and loneliness

The term social genomics is a new one to me. The fact that social factors influence health is not.

I wrote some time ago about the effects of self-described loneliness/social isolation has on the health of older adults. UCLA researchers examined the white cells of persons who were highest of the "high-lonely" vs. those "low-lonely" (socially connected) subjects.(1) A total of 209 genes showed different levels of expression between the two groups. Over 4 years of study, the lonely crowd over-expressed genes that resulted in inflammation and under-expressed those involved in antibody production against bacteria and viruses.

These DNA effects of social isolation were very specific to three groups of genes. The first group of affected genes are involved in the early phase of the immune response wherein the body revs up inflammation as a first response to injury or infection. I have written numerous times about the blessing/curse of inflammation insofar as appropriate levels are essential to a successful recovery from infection but too much (think cytokine storm in influenza pneumonia) or wrong place at the wrong time (say in an arterial wall that has cholesterol build-up) can be counter-productive or downright destructive.

The other two groups of immune genes that respond to the lonely soul's transformed internal environment are those that stimulate the production of interferon (a molecule that amplifies immune response against viruses) by lymphocytes and those that stimulate production of antibodies by B lymphocytes. The activity of both these types of genes is diminished in people who are less connected to friends and family.

The psychological literature abounds with studies in which socialization is correlated with susceptibility to viral illness. In another one of those 'who the heck volunteers for these things' type of study, researchers at Carnegie Mellon University assessed 193 subjects for PES (positive emotional style) vs. NES (negative emotional style of course) and then sprayed rhinoviruses/ common cold or influenza viruses up their noses to see who got sick.(2) Those NES-positive individuals, described as anxious, hostile, and depressed were 3 times as likely to succumb to the influx of nasal virus compared to all the PES prone Pollyanna types who were happy, lively, and calm.

Per Steve Cole, co-author of the study on white cells and loneliness: Research in social genomics has now clearly established that our interpersonal world exerts biologically significant effects on the molecular composition of the human body.(3) What remains to be seen is how attitude adjustments of the cognitive or pharmocological variety can affect how our DNA gets activated.
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1) Cole SW, et al. Social Regulation of Gene Expression in Human Leukocytes. Genome Biol. 2007;8(9):R189.
2) Cohen S, et al.Positive emotional style predicts resistance to illness after experimental exposure to rhinovirus or influenza a virus.Psychosom. Med. 2006 Nov-Dec;68(6):809-15. Epub 2006 Nov 13.
3) Cole SW. Social Regulation of Human Gene Expression. Current Dir. In Psych. Sci. 2009 Vol 18 No 3.