A systematic review and meta-analysis of 90 cohort studies of social isolation, loneliness and mortality

Social butterflies live longer!

Summary

This is a study from Harbin Medical University, China.  

It’s a meta-analysis of prospective studies from the psychology departments of various countries and universities that have looked at the effect of loneliness and Social isolation on deaths.  They found that people who felt social isolation and loneliness had a statistically significant higher risk of all-cause mortality, related especially to cancers and cardiovascular disease.  (.pdf available here)

Here is Dr. Been’sVideo on the subject Increased Deaths Associated with Isolation and Loneliness

Loneliness is subjective.  Have you ever felt lonely even when in a room full of people?

Social isolation is an objective (adj.) situation. One is in social isolation when they live alone or don’t socialize with people.  

Method

90 prospective studies involving 2.2 million people were chosen.   Some subjects were lonely, others were socially isolated.

The researchers looked at all-cause mortality related to cardiovascular disease, cancer and breast cancer alone.

And they found…

• Social Isolation increases all cause mortality by 32%.  Loneliness, by 14%. 95% confidence interval. (highly statistically significant)

• Loneliness increases all cause mortality by 14%.

• All Cause mortality in people with cancer increased by 24% in the socially isolated, and 9% in the lonely.

• Social isolation increased the risk of mortality in  people with cardiovascular disease, by 34%.

• All cause mortality was increased in socially isolated cardiovascular patients by 28% and in breast cancer patients by 51%.

•  Specific breast cancer deaths rose by 33% due to social isolation.

In their introduction, the authors suggest:

Several possible pathways have been proposed to explain the adverse effects of SI and loneliness on health and mortality. SI (social isolation) may promote unhealthy behaviours, such as malnutrition and physical inactivity , which may increase the risk of death. SI has also been associated with health-related biological processes, such as higher C-reactive protein and lipid levels and poorer immune function. In terms of loneliness, mechanisms including deleterious health behaviours, sleep disorders, and neuroendocrine and immune dysfunction have been identified as contributing to the negative association of loneliness and health.

TC: 14:58

We know that stress generates stress hormones which in turn can switch off many other healthy functions of the body.  So there is a physiological outcome as well .

The results of this study bring to mind the isolation we all experienced during the Covid-19 lockdowns.There has been much discussion about the increase in all-cause mortality during that time.  We are still struggling to grasp the impact, and studies like this one help us see it objectively.

People who are socially isolated or lonely are not necessarily in a position to repair their situation.  It is our job to make sure we reach out to bring some light and companionship to those who might not be in a position to ask for it or even know they need it.  

Those of us who lead busy lives, could also use a break to cultivate and nurture supportive relationships.