A healthy diet, physical activity, or either in relation to cardiovascular and all-cause mortality: A prospective cohort study.

Objectives: The aim of our study was to compare four lifestyles-healthy diet and low activity, unhealthy diet and high activity, unhealthy diet and low activity, and healthy diet and high activity-in relation to the risk of cardiovascular disease (CVD) and all-cause mortality.

Methods: A total of 6504 adults ages ≥35 y were recruited to participate in the Isfahan Cohort Study and followed for 13 y. Diet was assessed using a validated 48-item food frequency questionnaire, and the quality of diet was assessed using the Dietary Quality Index. Physical activity (PA) was evaluated using the International Physical Activity Questionnaire. The primary outcomes were CVD and all-cause mortality. Cox proportional hazards regression was used to calculate the hazard ratio (HR) and the 95% CIs.

Results: During 771 440 person-years of follow-up, 390 and 147 deaths occurred due to all causes and CVD, respectively. High PA, either with a healthy or unhealthy diet, was associated with a lower risk of death from CVD (HR = 0.43; 95% CI, 0.26-0.69, and HR = 0.32; 95% CI, 0.18-0.56, respectively) and also all-cause mortality(HR = 0.53, 95% CI, 0.39-0.71, and HR = 0.5, 95% CI, 0.36-0.68). Moreover, type of PA was important, such that when leisure time PA was considered, none of the lifestyles was associated with a lower risk of CVD and all-cause mortality. However, for occupational PA, the result was the same as the total PA.

Conclusions: Having high PA (total or occupational), with or without adhering to a healthy diet, is associated with a lower risk of death from any cause and CVD; although leisure time PA, irrespective of adhering to a healthy diet, was not associated with a lower risk of all-cause and CVD mortality.