Loneliness Can Wreak Havoc with Your Health, but More Than 372 Friends on Facebook Doesn’t Mean a Longer, Better Life

Image of a crowd.
A large group but some still lonely.

Research over the past several years has shown that loneliness can be hazardous to your health.

As an introvert, I’ve struggled to square this news with my occasional preference for time alone over, say a party with 250 of my closest friends.

We introverts may spend more time alone than would an extrovert, but that does not make introverts lonely. Now John Cacioppo, a social psychologist at the University of Chicago has described more precisely the aspects of isolation that may cause health concerns, as well as the biological mechanisms responsible for negative health effects due to loneliness. In an article in Science, recently, Greg Miller reviewed Cacioppo’s work. We learn here that it’s the experience of loneliness that can be negative, as opposed to the number of social contacts a person has.

Firstly, Cacioppo is not alone in the study of loneliness and health. In July 2010, PLoS Medicine published “Social Relationships and Mortality Risk: A Meta-analytic Review”. In this analysis of 148 studies, the authors found that social relationships had as much influence on mortality risk as more well-established risk factors, such as smoking and obesity.

Loneliness is a broad subject, and Cacioppo and collaborators have, since the early 1990s worked to get a handle on what it is about social isolation that brings health problems. Through surveys of thousands of college students followed by physiological and psychological evaluations, as well as studies with hundreds of Chicago residents, the researchers have found that loneliness on its own is a health risk, separate from the potential contributions of stress and depression. This is a distinction other studies have omitted.

And it is reassuring for those of us that value alone time. People can be alone or socially isolated without being lonely, assures Daniel Russell, a psychologist at Iowa State University. Russell was involved, in the 1970s with developing the UCLA Loneliness Scale, which is used by Cacioppo in his work. The scale is a questionnaire that analyzes how people feel about their social situation, whether and how often they feel they have no one to talk to or feel out of touch with those around them.

Basically when people score high on the UCLA Loneliness Scale, they are found to exhibit physiological changes that match stress markers when the body is on a high state of alert. In one study those that scored high on the loneliness scale exhibited higher vascular resistance. This arterial tightening raises blood pressure and causes the heart to worker harder, with negative effects on blood vessels.

Loneliness was also found to elevate markers of stress, such as cortisol and epinephrine, as measured in saliva and urine. These elevated stress markers helps to explain why people that score high on the loneliness scale report feeling more stressed in situations that other non-lonely people report as only moderately stressful.

These findings point to loneliness as causing sympathetic nervous system activation. The sympathetic nervous system coordinates the body’s fight or flight instinct. Thus loneliness can predispose a person to feelings of vulnerabity or suspectibility to attack. This makes good evolutionary sense. For early humans, being alone meant lacking protection from predation. Plus a genetic contribution to the group was endangered when an individual’s life was in danger.

There is wear and tear associated with being in alert mode too much. Cacioppo et al. reported in March 2010 that although lonely people sleep a normal number of hours, they report more fatigue, suggesting that their quality of sleep isn’t as good (March 2010 Health Psychology).

Additional work presented in this article shows how the stress of loneliness affects the brain and brain function.

Happily, there are interventions that work to reduce loneliness and its negative health effects. Cacioppo notes that the most effective interventions borrow from behavioral therapy, to change and improve a person’s interpretation of a social situation. Simply being more “open and available to others” is what Cacioppo calls a step in the right direction.

So whether we are open and available to many or just a few friends, what appears to be most important is how we view our social situations and friendships. This perspective is what impacts our health.

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Kari Kenefick

Kari Kenefick

Kari has been a science writer/editor for Promega since 1996. Prior to that she enjoyed working in veterinary microbiology/immunology, and has an M.S. in Bacteriology, U of WI-Madison. Favorite topics include infectious disease, inflammation, aging, exercise, nutrition and personality traits. When not writing, she enjoys training her dogs in agility and obedience. About the practice of writing, as we say for cell-based assays, "add-mix-measure".


  1. These findings are very interesting but not surprising. When you look at those with chronic illness who are frequently cut off from much of society, the negative effects of social isolation and loneliness on overall wellness can be seen even more clearly. It means that we really need to take those extra steps to watch for loneliness in those around us.

    1. Thanks Robert, for the reminder of your blog on Cacioppo’s work from April 2010. have just reread your piece…is interesting and related to loneliness. Interesting story of your “migration” to the U.S. as well! -Kari

  2. I found this post very interesting. Loneliness is a broad subject. I totally agree,we need to be aware of other people around us, which a kind word spoken or just a smile might add a little happiness in their day.

    1. Thanks for the comment and reminder, Penny. It is amazing how a smile can brighten a person’s day, especially when one is feeling down or alone (that is to say, lonely). Doesn’t cost a thing either, does it! Kari

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