Both social isolation and loneliness are associated with increased mortality, but it is uncertain whether their effects are independent or whether loneliness represents the emotional pathway through which social isolation impairs health. People who are socially isolated are more likely to die prematurely, regardless of their underlying health issues, according to a study of the elderly British population.
The research found on Monday in the Proceedings of the National Academy of Sciences, showed that when mental and physical health conditions were factored out, the lack of social contact continued to lead to early death among 6,500 men and women tracked over a seven-year period.
People were recorded as dying from natural, normal causes but, isolation did have a strong influence as well. The study also appeared to diminish the role that subjective feelings of “loneliness,” as opposed to the lack of social contact, may have on a person’s life span. Both lead to higher mortality rates, but the effects of feeling lonely is reduced once demographic and health factors are weighed in.
Regardless of the distinction, the study reinforces the need to increase social support for the elderly, even as it adds to debate over the intertwined effects of social contact and feelings of loneliness in old age. A similar look at retired Americans in 2012 reinforced multiple studies that link loneliness to numerous illnesses, including heart trouble and high blood pressure.
Both studies come as British and U.S. populations have become more solitary. People living alone compose more than a quarter of U.S households, and the proportion of Americans who said they had no one to talk to about important matters grew from 10% in 1985 to 25% in 2004.
Separating the effects of loneliness from those of isolation, however, has not been easy for those who study rates of illness and death. While isolation can be measured directly — by how many friends you have or how often you have contact with family — loneliness is more subjective, measured through survey questions about whether social needs and expectations are being met.
Anyone familiar with Henry David Thoreau knows that isolation does not necessarily lead to loneliness, while the story of Marilyn Monroe shows that a strong social life can still leave you lonely.
Last year’s report on loneliness, based on the U.S. Health and Retirement Study, showed that loneliness appeared to increase mortality risk over a six-year period, an association that could not be attributed to social relationships or health behaviors, such as smoking and drinking.
The National Institute on Aging, part of the National Institutes of Health, funded both the British study and last year’s report on U.S. retirees. Loneliness and isolation “should get lots of attention because they may be as important, as joint factors, as smoking.” 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.