Abstract
IMPORTANCE: Greater diet quality and physical activity level are associated with a lower risk of developing Parkinson disease (PD). However, information regarding the association between lifestyle behaviors and survival after PD diagnosis remains limited. OBJECTIVE: To examine the association of prediagnosis and postdiagnosis overall diet quality and physical activity with all-cause mortality among individuals with PD. DESIGN, SETTING, AND PARTICIPANTS: This population-based cohort study analyzed male participants in the Health Professionals Follow-up Study from 1986 to 2012 and female participants in the Nurses' Health Study from 1984 to 2012. Participants who were diagnosed with PD and had complete baseline dietary assessment data were included. Data were analyzed from January 2021 to February 2022. EXPOSURES: Prediagnosis diet quality, assessed by the Alternative Healthy Eating Index (AHEI), and physical activity, assessed by metabolic equivalent task (MET) hours per week reported on questionnaires, were the primary exposures of interest to minimize reverse causation. MAIN OUTCOMES AND MEASURES: Mortality, which was followed up until 2018, was the primary outcome. Cox proportional hazards regression models were used to estimate the association of diet and physical activity with mortality individually and jointly, and the models were adjusted for age, total energy intake, caffeine intake, and other lifestyle risk factors. RESULTS: The sample comprised 1251 individuals with PD, which included 652 men (52.1%) with a median (IQR) age at diagnosis of 73.4 (67.5-78.7) years. During the 32 to 34 years of follow-up, 942 participants died. The adjusted hazard ratio (HR) comparing the highest vs the lowest AHEI quartile was 0.69 (95% CI, 0.56- 0.85) for prediagnosis analyses and 0.57 (95% CI, 0.42-0.78) for postdiagnosis analyses. Similar results were obtained for cumulative mean MET hours per week in the prediagnosis analyses (HR, 0.71; 95% CI, 0.57-0.87) and postdiagnosis analyses (HR, 0.47; 95% CI, 0.35-0.63). The inverse association persisted for PD-specific mortality (postdiagnosis AHEI: HR, 0.52 [95% CI, 0.33-0.80]; postdiagnosis physical activity: HR, 0.37 [95% CI, 0.25-0.55]). In the joint analyses of diet quality and physical activity before the PD diagnosis, the adjusted HR was 0.51 (95% CI, 0.36-0.73) for individuals in the highest vs lowest tertiles for both variables. The HR for diet quality and physical activity after the diagnosis was 0.35 (95% CI, 0.23-0.52). CONCLUSIONS AND RELEVANCE: Results of this study showed that a healthy dietary pattern and an active lifestyle were associated with a lower rate of all-cause mortality among individuals with PD. Consuming a healthy diet and engaging in physical activity or exercise could be targeted to improve PD outcomes.