Why Being Alone Is Hazardous to Your Health

It’s been well established that social isolation is a serious health risk, particularly for seniors. A 2010 study showed that too much alone time can be just as dangerous as smoking 15 cigarettes a day. Many scientists have assumed that loneliness is the culprit, and subsequent research has backed this suspicion. But a new study is overturning this view, showing that even people who don’t mind being alone are still significantly more likely to die when their social networks are diminished.

The recent study was conducted at the University College London by epidemiologist Andrew Steptoe and his colleagues who looked at data from 6,500 men and women over the age of 50. Back in 2004 and 2005, they all filled out questionnaires assessing their levels of loneliness. The researchers looked at social isolation in terms of contact with family members and friends, and participation in local groups (like civic organizations). Participants also answered a standard questionnaire that measured loneliness. The researchers then tracked the participants’ health over the course of the next seven years.

Looking at the data, the researchers found that social disconnectedness was linked to higher mortality, regardless of the cause of death. The research showed that the most socially isolated subjects had a 26% greater risk of dying. The correlation still held true even after the researchers adjusted for other factors, like pre-existing health conditions, socioeconomic status, sex, and age. But unintuitively (and unexpectedly), loneliness, as a factor on its own, could not be linked to the deaths.

“The association of social isolation with mortality was unchanged when loneliness was included in the model,” wrote the authors. They continue:

However, the effect of loneliness was not independent of demographic characteristics or health problems and did not contribute to the risk associated with social isolation. Although both isolation and loneliness impair quality of life and well-being, efforts to reduce isolation are likely to be more relevant to mortality. [emphasis added]

The results suggest that lack of social contact is a more significant risk factor than loneliness.

"In many ways, social isolation and loneliness are two sides of the same coin,” explained Steptoe. “Social isolation indicates a lack of contact with friends, relatives and organizations, while loneliness is a subjective experience of lack of companionship and social contact.”

But why isolation is such a potent predictor of death isn’t immediately obvious.

According to Julianne Holt-Lunstad, there may be two possible mechanisms by which a thriving social network of friends and family could contribute to good health.

First, the ongoing support of other people may reduce the harmful effects of stress (even if someone is happy in their solitude); it could be that isolation reduces immune function. And second, the influence of others may also encourage behaviour that contributes to good health (such as eating properly, taking medications, and practicing proper hygiene).

Steptoe agrees, saying that, “When you’re socially isolated, you not only lack companionship in many cases, but you may also lack advice and support from people.”

Consequently, physicians, health professionals, educators and the public media need to start taking social disconnection seriously. Armed with this knowledge, medical professionals should routinely evaluate patients' social networks, and recommend more connections with other people.

It's worth noting that the Steptoe study looked at people over the age of 50. But other research has shown that social isolation is a risk factor for all people, regardless of age.

Read the entire study at PNAS.

Image: DC Comics.