Yes, Loneliness Can Make You Sick and Scientists Explain Why

Rebecca Lewis December 01, 2015

It is normal to feel lonely at times. But if it becomes too frequent that it is already affecting many areas of your life, it’s time that you pay more attention to it. Otherwise, it may take a huge toll on your health - new research suggests. In the study, social isolation is linked to 14 per cent higher risk of premature death among older adults.

While they have long known the health dangers of loneliness, this is the first time that researchers identified the cellular mechanisms that cause these negative outcomes.

Appearing in the Proceedings of the National Academy of Sciences, the study found that loneliness leads to fight-or-flight stress signalling, which can ultimately affect the production of white blood cells.

In their previous study, researchers identified a link between loneliness and a phenomenon they called "conserved transcriptional response to adversity" or CTRA. This response is characterized by an increased expression of genes involved in inflammation and a decreased expression of genes involved in antiviral responses. Essentially, lonely people had a less effective immune response and more inflammation than non-lonely people. They then examined gene expression in leukocytes, cells of the immune system that are involved in protecting the body against bacteria and viruses.

The increased expression of genes is involved in inflammation and a decreased expression of genes involved in antiviral responses.

The team from University of California, Davis also investigated the cellular processes linking social experience to CTRA gene expression in rhesus macaque monkeys at the California National Primate Research Centre, which had been behaviourally classified as high in perceived social isolation. Like the lonely humans, the "lonely like" monkeys showed higher CTRA activity. They also showed higher levels of the fight-or-flight neurotransmitter, norepinephrine. In previous research, it was found that norepinephrine stimulates blood stem cells in bone marrow to make more of a particular kind of immune cell—an immature monocyte that shows high levels of inflammatory gene expression and low levels of antiviral gene expression.

Currently, the research team is exploring ways on how the health effects of loneliness can be prevented in older adults.

Source of this article:

Myeloid differentiation architecture of leukocyte transcriptome dynamics in perceived social isolation