Researchers have discovered that lonely individuals, genetically speaking, become distinct from their non-lonely peers, reports Spirituality & Health (March-April 2008). Gene expression is the process in which genes “switch on,” activating the genetic directions stored inside. The genes of persistently lonely people express themselves in ways that correlate with overactive immune reactions (like inflammation), but decreased antiviral responses and antibody production.
These factors explain why loneliness is associated with a host of health problems, including heart disease, infections, and cancer. There’s one hopeful twist: The genetic expressions are linked to subjective experiences of social isolation. It doesn’t matter how big your social circle is; it matters how you feel about it—a compelling reason to keep on the sunny side. One researcher suggested to Discover (Jan. 15, 2008) that we might usefully reframe loneliness as a warning sign, like physical pain, that “makes us care for other people and want to reconnect.”