Socially isolated people die sooner
Social isolation can be defined as the objective state of having few social connections or infrequent contact with other people. Scientists widely believe that social isolation is undesirable for most people. But is social isolation associated with a shorter life? A recent study used data from the English Longitudinal Study of Aging to evaluate the association of both social isolation and loneliness with mortality. Six thousand five hundred men and women over age 52 were followed for an average of 7 years. The researchers created an index of social isolation using answers to five items: 1) not married; 2) less than one monthly contact with children, 3) other family members, 4) friends; and 5) not participating in any social organization. Loneliness was evaluated according to response to one question: How often do you feel lack of companionship? The researchers compared the risk of dying for persons in the highest and lowest quintiles of social isolation and loneliness. The researchers found that social isolation but not loneliness predicted mortality for both men and women after accounting for confounding factors. The increased risk of dying for the most socially isolated people compared to the least socially isolated ranged 50 to 26 percent depending on which confounding factors were included in the statistical models. Social isolation is more than simply undesirable: it might shorten your life.
Social isolation may be as bad as smoking
How does social isolation compare to traditional risk factors for premature death? Researchers at Stanford and the University of California used data from 16,849 adult participants in the Third National Nutrition Examination Survey (NHANES III) to answer this question. Social isolation was assessed with the Berkman-Syme Social Network Index, a composite score ranging from 0-4 based on answers to four criteria: 1) living with at least one other person, 2) talking to two or more persons about important matters in the past years, 3) attending religious services in the past month, and 4) participation in clubs or groups or doing volunteer work in the past month. Low scores indicate high social isolation.
For both men and women, increasing social isolation was associated with lower survival over a median follow-up of 14 years. Men and women participants with high social isolation had a 62 and 72 percent higher risk of death, respectively, than men and women with low social isolation. These elevated risks were comparable to elevated mortality risks for smoking (72 and 86 percent for men and women, respectively), and higher than elevated mortality risks for high blood pressure (16 and 32 percent for men and women, respectively). It’s ironic that your doctor probably inquires if you smoke but probably doesn’t inquire about your social connections.
Social isolation and cognitive function
Retaining cognitive capabilities comprises a key aspect of healthy aging. The rate of cognitive aging varies among older people. Some of that variation may arise from adopting (or not adopting) healthy lifestyle choices. Researchers in the UK used data from up to 2,224 participants with an average of 74 years in the Cognitive Function and Aging Study—Wales to understand links between social isolation and cognitive function. Eight aspects of cognitive function were evaluated with the Cambridge Cognitive Evaluation. Social isolation was measured with the Lubben Social Network Scale. A proxy for cognitive function, which refers to the ability of individuals to develop protective mechanisms to counter decline in brain health. The proxy included education, occupational complexity, and cognitive ability at baseline.
At baseline, participants with more social isolation had lower cognitive function, fewer years of education, were older, more likely to be men, and participated in fewer cognitive activities. Over two years of follow-up and compared to participants with more social isolation, participants with less social isolation showed less decline in cognitive function—but only for men and not for women. Furthermore, participants with higher occupational complexity showed less decline in cognitive function of during follow-up compared to participants with lower job complexity. Overall, social isolation late in life predicts lower cognitive function.
Social isolation may promote chronic inflammation
Social isolation may lead to psychological, biological, and behavioral responses that may promote inflammatory processes, which predict increased rate of aging. Researchers at Johns Hopkins University tested this idea using cross-sectional data from 4,648 participants with an average of 76 years in the National Health and Aging Trends Study. Social isolation was assessed with the Berkman-Syme Social Network Index as noted above. Markers of inflammation included C-reactive protein and interlukin-6 measured on dried blood samples.
Social isolation and severe social isolation were more common in participants who were older, had lower incomes, ever smoked, had three or more chronic conditions, and who were frail. After full multivariable adjustment, participants who were socially isolated or severely socially isolated had significantly higher levels of C-reactive protein than participants were not socially isolated. Similarly, participants who were socially isolated had significantly higher levels of interlukin-6 compared to participants who were not socially isolated. This study provides evidence that adverse health effects of social isolation might operate via increased inflammation.
Social isolation predicts greater risk of dementia
Studies suggest that social isolation increases risk of dementia. A new study extended this line of research by using a nationally representative sample of 5,022 community-dwelling Americans with an average of 74 years in the National Health and Aging Trends Study. Participants with social isolation demonstrated either none or one of the following four conditions: 1) living alone, 2) talking with two or more people about important matters in the last year, 3) attending religious services in the last month, and 4) participating in other group activities. Overall, 23 percent of the participants were socially isolated, close to the national average of 25 percent. After adjusting for confounding factors, socially isolated participants had a significant 27 percent higher risk of developing dementia during an average follow-up of 5 years. These results were not affected by race or ethnicity, perhaps due to small numbers of participants in various racial or ethnic categories. Socially isolated people may be more prone to dementia due to reduced cognitive activity, or lack of social engagement, or failing to benefit from available social resources. Given that dementia is one of the most debilitation human conditions, wouldn’t it make sense for you to find ways to be more socially connected?