Here’s the press release from Genome Biology, “People who experience chronically high levels of loneliness show gene-expression patterns that differ markedly from those of people who don’t feel lonely.” The study’s lead author, Steven Cole, notes: “In this study, 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 for inflammation, such as health status, age, weight, and medication use. The changes were even independent of the objective size of a person’s social network. 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.”
Please note that these are changes in the gene expression in cells, in this case leukocytes: “The leukocyte transcriptome appears to be remodelled in chronically lonely individuals,” said Dr. Cole. Cortisol, the stress hormone, is one candidate for how subjective loneliness impacts immune function. Cortisol impacts immune activity, and is released from the adrenal glands as part the hypothalamic-anterior pituitary-adrenal cortex (HPA) system. In other words, the HPA is a brain-body system that can be impacted by subjective experience, among other things. Mark Flinn, Robert Quinlan and David Leone write in the December 2007 Anthropology News about their research in Dominica. “Our research on stress and health on children in this rural Dominican community indicates that they are more than twice as likely to become ill during the week following a stressful event than during a week they had not recently experienced any significant stressors… Analyses of data on children’s activities, their reported psychological states, growth, morbidity (illness) and salivary cortisol indicate the importance of family and other kin as both a source of and a buffer for psychosocial stress and associated health effects.” As Flinn (2007) writes elsewhere, “Traumatic family events were associated temporally with elevated cortisol levels… Children born and raised in household environments in which mothers have little or no mate or kin support were at greatest risk for abnormal cortisol profiles and associated health problems. Because socioeconomic conditions influence family environments, they have consequences for child health that extend beyond direct material effects (257-258).”
Be sure to check on Greg’s post on “How Your Mood Affects Your Health” for more on this topic at: https://neuroanthropology.wordpress.com/2007/12/20/how-your-mood-affects-your-health/
Steve W Cole, Louise C Hawkley, Jesusa M Arevalo, Caroline Y Sung, Robert M Rose and John T Cacioppo (2007). Social regulation of gene expression in humans: glucocorticoid resistance in the leukocyte transcriptome. Genome Biology 8:R189.
Download here: http://genomebiology.com/content/pdf/gb-2007-8-9-r189.pdf
Flinn, Mark V. (2007). Why words can hurt us: Social relationships, stress and health. In: W. Trevathan, E.O. Smith, & J.J. McKenna, eds., Evolutionary Medicine and Health: New Perspectives. Oxford: Oxford University Press. Pp. 242-258.