Black and white image of older female watering plants indoorsShare on Pinterest
Social isolation and loneliness are both associated with an increased risk of all-cause mortality, a large new study finds. izusek/Getty Images
  • Social isolation and loneliness are both associated with an increased risk of all-cause mortality, finds an expansive new meta-study.
  • In addition, among people with cancer, social isolation and loneliness are linked to a higher risk of death.
  • For people with heart disease, social isolation, not loneliness, is associated with a higher mortality risk.

A new study confirms an association between social isolation, loneliness, and mortality.

The authors investigated how the two phenomena were linked to all-cause deaths and deaths from cardiovascular disease and breast cancer.

The large meta analysis found that being socially isolated was associated with a 26% increase in the risk of all-cause death compared to people who were not socially isolated.

The effect of loneliness was slightly less but still concerning: The chance of death for people experiencing prolonged loneliness was 14% higher than for people who were not lonely.

Both social isolation and loneliness were linked to an increase in the likelihood of all-cause and cancer deaths. Social isolation was also associated with an increased risk of death for people with cardiovascular disease.

The meta-study analyzed the findings of 90 separate studies involving 2,205,199 people.

The analysis is published in nature human behavior.

One of the interesting aspects of the study is social isolation’s greater effect on mortality than loneliness. The two conditions might seem similar. However, they are not the same:

  • The study defines “social isolation” as “an objective lack of (or limited) social contact with other people, and is characterized by a person having a limited social network, having infrequent social contacts, or possibly living alone.”
  • “Loneliness,” on the other hand, is “a subjective feeling of distress, arising when there is a discrepancy between desired and actual social relationships.”

It is possible to be socially isolated without feelings of loneliness and, for example, to feel lonely in a group of people, even if those people are known.

Dr. Rosanne Freak-Poli, an epidemiologist and senior research fellow at Monash University, not involved in the study, told Medical News Today that with the new study, “two landmark meta-analytical studies have identified that social isolation is a stronger risk factor for mortality than loneliness.”

Dr. Angelina R. Sutin, PhD, a professor at the College of Medicine at Florida State University, not involved in the research, told MNT that when social isolation is not causing loneliness in an individual, there are at least a couple of reasons why it can be harmful.

One is that socially isolated people may have no one to help them get to a doctor regularly, either because they lack transportation, or because some procedures require an accompanying individual.

“Second,” Dr. Sutin added, “people are not always aware of changes that are happening to them, or when it is time to go see a doctor.”

Other people can be better at noticing changes and getting the care they need. In both cases, said Dr. Sutin, “Delaying care can have significant consequences.”

Dr. Freak-Poli’s research indicates that some unhealthy responses associated with loneliness may also occur with social isolation. She said her research has shown that both social isolation and loneliness are associated with health effects such as:

  • elevated blood pressure
  • high triglycerides
  • overweight and obesity
  • lower quality of life
  • poor mental health

“Someone who is socially isolated or experiencing loneliness is more likely to partake in unhealthy lifestyle behaviors, which may further contribute to their social isolation and loneliness, sending them into a downward spiral.”

— Dr. Rosanne Freak-Poli, epidemiologist

One source of social isolation commonly cited in conversation is our increasing dependence upon online relationships.

“The use of devices can be socially isolating for some and a lifeline for others,” Dr. Sutin said.

“The challenge now is to determine when and how online relationships can be healthy and who will benefit the most from in-person versus virtual social contact,” she added.

Dr. Freak-Poli noted that how online communication occurs determines whether it is helpful or harmful.

“If social media is being used to communicate directly with people in a meaningful way, it can have benefits,” she said.

“There is research demonstrating that apps allowing people to see each other’s faces when talking — for example, Teams, Zoom, or FaceTime — can have benefits for social engagement, lower loneliness, and better well-being,” she said.

Dr. Sutin noted the new meta-study is “a nice summary of that literature and calls attention to the harmful effects of both loneliness and social isolation.”

“It also more specifically documents that loneliness and social isolation increase [the] risk of cause-specific mortality and among specific patient populations. [The study] underscores that relationships and social connection matter, and the dire consequences when social needs are not met,” Dr. Sutin added.

“Experiencing social isolation and loneliness are unfortunately likely inevitable at some point in one’s life, as they are part of the human condition,” Dr. Freak-Poli said.

Dr. Freak-Poli stated her belief that “initiating social interaction is an achievable goal.”

She said she has found that participating in community activities at least once per month and having contact with five or more relatives or close friends per month can substantially benefit one’s health.

Loneliness can affect health in a few ways, Dr. Sutin said, noting that lonely people often resort to unhealthy lifestyle choices such as:

  • smoking
  • substance misuse
  • becoming more sedentary
  • forgoing mentally stimulating activities

Lonely people, cautioned Dr. Sutin, “may also be less likely to participate in preventive care and screenings that can both prevent and detect disease when it is most likely to be treatable.”

Dr. Mary Louise Pomeroy, PhD, MPH, a postdoctoral research fellow at Johns Hopkins University noted the mental health effects of loneliness to MNT:

“Loneliness is of particular concern for poor mental health (depression, stress, anxiety), which may lead to a higher risk of mortality through negative health behaviors either directly (i.e., suicide) or indirectly (e.g., smoking as a social activity or to alleviate boredom or distress).”

Of course, feeling lonely is undeniably stressful, and chronic stress has been linked to various health issues

While the study authors found that social isolation posed a greater health danger compared to loneliness, that is not to minimize the harmful effects of chronic loneliness, which could affect anyone.

Dr. Freak-Poli pointed out that the study is concerned with severe loneliness.

“For example, feeling lonely a day a week — even if it is regular — is not all that concerning from a health perspective.”

“However, if someone feels lonely three or more days per week over some time, then we should be concerned as there is evidence that it is likely to influence their health and well-being,” Dr. Freak-Poli noted.

Other research has documented increased loneliness that occurred with the COVID-19 pandemic.

But depending on where you live, most, if not all, COVID-related social restrictions are no longer in effect.

She also noted that we are more conscious now of how we communicate and socialize — or not — compared to pre-pandemic times.

For instance, some people may prefer to socialize less, after gaining perspective from their previously over-busy lives.

Still, the U.S. Surgeon General recently warned of an ongoing “loneliness epidemic” and issued an advisory on the importance of social connection.

Dr. Freak-Poli said she is not surprised.

“COVID-19 changed the structure of our daily lives and made us more aware of human social contact. This awareness of human social contact can now not be unseen,” she said.

Dr. Freak-Poli concluded that community programs and services are slowly being re-established, which could help facilitate social connections among individuals who’ve experienced loneliness in recent times.