Prediagnosis and Postdiagnosis Diet Quality, Physical Activity, and Mortality Risk Among Individuals with Parkinson Disease: A Prospective Cohort Study

OBJECTIVES: Greater diet quality and physical activity level are associated with a lower risk of developing Parkinson disease (PD). However, information regarding these lifestyle behaviors and survival after PD diagnosis remains limited. This study aimed to examine the association between prediagnosis and postdiagnosis diet quality, physical activity, and mortality among individuals with PD. METHODS: We included 652 men from the Health Professional Follow-up Study (1986–2012) and 599 women from the Nurses’ Health Study (1984–2012) who were diagnosed with PD and had complete baseline dietary assessments. Diet quality was assessed by the Alternative Healthy Eating Index (AHEI), and overall physical activity was assessed by metabolic-equivalent hours per week (MET-h/wk) based on questionnaires. Mortality was followed up until 2018. Cox proportional hazard models were used to estimate the association between prediagnosis and postdiagnosis diet quality/physical activity and mortality, individually and jointly, adjusting for age, total energy intake, caffeine consumption, and other lifestyle risk factors. RESULTS: During 32–34 years of follow-up, we identified 529 deaths in men and 413 deaths in women. Better diet quality was associated with lower mortality rates both before and after the diagnosis of PD (p-trend < 0.005 for both). Similar results were obtained for physical activity (p-trend < 0.005 for both before and after the PD diagnosis). In joint analyses of diet quality and physical activity before the PD diagnosis, the adjusted hazard ratio [HR] was 0.51 (95% confidence interval [CI]: of 0.36, 0.73) for individuals in the highest tertiles for both variables relative to those in the lowest tertiles. The comparable HR for diet quality and physical activity after the diagnosis was 0.35 (95% CI: 0.23, 0.52). Similar patterns were observed for PD-specific mortality. CONCLUSIONS: Adherence to a healthy dietary pattern and an active lifestyle was associated with a lower rate of mortality among individuals with PD. Reverse causation cannot be totally excluded and the results need to be interpreted with caution. FUNDING SOURCES: This study was supported by the National Institute of Neurological Disorders and Stroke grant 1R01NS102735-01A1.