Socioeconomic Status, Diet, and Behavioral Factors and Cardiometabolic Diseases and Mortality.

Importance: It remains unclear how socioeconomic status (SES) is related to the association between diet and health, as well as the role of behavioral factors, in explaining socioeconomic disparities in health outcomes. Objective: To investigate the associations of neighborhood and individual SES factors, as well as behavioral factors, particularly dietary pattern, with health outcomes. Design, Setting, and Participants: This prospective cohort study included US health professionals without chronic diseases at baseline who were enrolled in the Health Professionals Follow-Up Study (calendar years 1988-2018), the Nurses' Health Study (calendar years 1992-2018), and the Nurses' Health Study II (calendar years 2001-2019). Data analysis was performed in September 2023. Exposures: Repeated questionnaires were used to assess neighborhood and individual SES factors and behavioral factors, including dietary pattern (assessed using the Alternative Healthy Eating Index 2010), alcohol intake, body mass index, cigarette smoking, physical activity, sedentary television-viewing time, and sleep duration. Main Outcomes and Measures: The main outcomes were incident major cardiovascular disease (CVD), type 2 diabetes (T2D), and total mortality. The associations of SES and behavioral factors with outcomes were analyzed using multivariable Cox proportional hazards regression models with hazard ratios (HRs) per 10th- to 90th-percentile increments. Results: The study analyzed 152 192 participants for major CVD (mean [SD] age, 52.0 [8.7] years; 125 959 female [82.8%]), 151 217 participants for T2D (mean [SD] age, 52.0 [8.6] years; 125 231 female [82.8%]), and 141 145 participants for mortality (mean [SD] age, 51.6 [8.5] years; 117 627 female [83.3%]). A healthy dietary pattern was inversely associated with risk for major CVD (HR, 0.87 [95% CI, 0.82-0.93]), T2D (HR, 0.79 [95% CI, 0.75-0.84]), and total mortality (HR, 0.84 [95% CI, 0.81-0.88]). Without adjusting for neighborhood and individual SES factors, the HRs were 0.85 (95% CI, 0.80-0.91) for risk for major CVD, 0.78 (95% CI, 0.74-0.82) for T2D, and 0.82 (95% CI, 0.79-0.85) for total mortality. Neighborhood SES was inversely associated with risk for major CVD (HR, 0.90 [95% CI, 0.85-0.95]), T2D (HR, 0.92 [95% CI, 0.88-0.97]), and total mortality (HR, 0.91 [95% CI, 0.88-0.94]). Behavioral factors accounted for a large proportion of the associations with risk for major CVD (46.3% [95% CI, 32.5%-60.6%]), T2D (77.4% [95% CI, 64.5%-86.6%]), and total mortality (42.8% [95% CI, 32.9%-53.3%]). Conclusions and Relevance: In this prospective cohort study of health professionals, associations between diet and health outcomes remained similar without adjusting for SES factors, while health behaviors, including diet, accounted for a large proportion of the associations between neighborhood SES and health. These findings highlight the importance of health behaviors, particularly high-quality diets, in promoting individual health and possibly reducing health disparities associated with SES.