How health behaviors link romantic relationship dysfunction and physical health across 20 years for middle-aged and older adults

Rationale: There has been substantial research linking marital quality to physical health outcomes; however, the mechanisms linking marital quality and physical health have been studied less extensively, especially with longitudinal data. Of the hypothesized mechanisms, only psychological distress (anxiety/depression) and physiological mechanisms (inflammation) have been tested and confirmed. Health behaviors such as diet, exercise, smoking, drinking, and sleeping have not previously been examined as mechanisms linking marital quality and physical health. Objective: The present study tests how the emotional influence of the marital relationship is linked to subsequent health outcomes through behavioral mechanisms. A biopsychosocial theoretical model, the Biobehavioral Family Model (BBFM), is used to hypothesize the mediating paths between marital dysfunction and physical health. Method: The study hypotheses are tested with publicly accessible survey data, Midlife in the United States (MIDUS). We examined married or cohabiting participants (N = 5023) across the three time points of MIDUS, or 20 years. Specifically, we tested whether five health behaviors at Time 2 (smoking, alcohol, sleep, food to cope, and physical activity) function as mechanisms linking marital dysfunction (Time 1) to subsequent physical health (Time 3). We tested each health behavior as a mechanism in a series of mediating Structural Equation Models. Results: Two health behaviors were significant mechanisms (food to cope and physical activity), while three were not (smoking, alcohol, and sleep). Conclusion: Diet and exercise are mechanisms linking marital dysfunction and health across 20 years because they may be linked to the emotional influence and not functional influence of the marriage context. According to the BBFM, diet and exercise may be part of the mediating construct of the model (i.e., biobehavioral reactivity), which explains how emotional stress from a marriage may produce declines in physical health over time. Implications for biopsychosocial healthcare interventions are discussed.