Loneliness Takes Toll on Cellular Level: Here's Why Its Bad For You

Loneliness is not a desirable thing. Now, a new study has found another reason why one should not be lonely: it negatively affects health, and might increase the risk for a premature death by as much as 14 percent.

The Huffington Post reported that science has known for some time that loneliness has been linked to health problems such as high blood pressure, inflammation and weak immunity to sickness. However, it is only very recently that loneliness has been found to negatively affect the body on a cellular level.

Loneliness can lead to a weaker immune system, which can lead to serious health problems.

"Feeling lonely means you are not in a socially affine environment but rather in a relatively hostile environment," Dr. John Cacioppo, a professor of psychology and behavioral neuroscience at the University of Chicago and a co-author of the study, told THP.

The study, which is published in the Proceedings of the National Academy of Sciences, examined the genetic effects of loneliness on two sets of participants: elderly humans (aged 50-68) from the Chicago Health, Aging, and Social Relations study; and rhesus macaques, a highly social primate species.

The researchers specifically looked into the effects of loneliness on the gene expression in leukocytes. These cells are involved in protecting the body against bacteria and viruses. The findings are explained in detail in a press release.

The researchers found that the leukocytes of lonely humans tend to have decreased antiviral responses. More than that, they have several additional findings that are interesting.

First, they found that loneliness predicts future gene expression even up to a year later. Interestingly, gene expression also predicts loneliness – suggesting that both help each other propagate over time. This finding is specific to loneliness alone, and is not found in depression, stress, or in situations involving social support.

Next, the researchers found that rhesus macaques, known to be highly social, are also affected negatively. They have been found to have higher levels of the neurotransmitter norepinephrine.

Norepinephrine has been found to stimulate the production of immature monocytes. These immune cells have lowered antiviral responses, and have been found at high levels in both lonely humans and “lonely like” monkeys.

Lastly, the researchers found via a monkey model of viral infection that the simian immunodeficiency virus (the primate version of HIV) developed faster in the blood and brains of “lonely like” monkeys.

In summary, the findings report that loneliness, or perceived isolation, can lead to “fight-or-flight” signalling, which in turn increases the production of immature monocytes, that weaken immunity to sicknesses.