How do loneliness and social isolation impact physical health in middle and later life? A population-based longitudinal study from Norway

Abstract

Growing concerns about declining health with ageing highlight the urgent need to promote healthy ageing. Loneliness and social isolation are established risk factors for health decline, however, it is largely unclear whether there are differential impacts or pathways between these two factors. The objectives of this study are therefore to examine the separate and combined impacts of loneliness and social isolation on physical health, as well as potential biological, behavioural, and psychological pathways linking loneliness and social isolation to health. Data are derived from the second and third wave (2007 and 2017) of the Norwegian Life-Course, Ageing, and Generation Study (N = 4,304). Data on loneliness, social isolation, potential mediators, and confounders were obtained from the second wave of the survey. Clinically relevant change in physical health between the two waves was assessed with the Edwards-Nunnally index. Stepwise multivariate linear regression analyses showed a separate, but similar significant impact of loneliness and social isolation on decline in physical health. The combined effect of loneliness and social isolation was non-significant. Regarding the pathways linking loneliness with physical health, this study found support for psychological pathways, but not for biological and behavioural pathways. For the link between social isolation and physical health, the present study found support for behavioural and psychological pathways, but not for biological pathways. These findings indicate the need for tailored interventions for addressing the negative health impacts of loneliness and social isolation. To enhance healthy ageing, psychological interventions are recommended for lonely and socially isolated individuals, and promoting a healthy lifestyle may have an additional benefit for socially isolated individuals.