Associations between plant-based dietary patterns and sensory impairments among Chinese older adults: Based on the Chinese Longitudinal Healthy Longevity Survey

Introduction: The aim of this study was to investigate the relationship between the plant-based dietary index and vision impairment (VI), hearing impairment (HI), and dual sensory impairment (DSI) among Chinese aged 65 and older. Methods: Based on the 2018 data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), a cross-sectional study was conducted on 14,859 samples. The assessment of dietary quality utilized the plant-based diet index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI). Logistic regression analysis was used to examine the associations between PDIs and sensory impairments. Additionally, restricted cubic spline analysis was utilized to investigate the nonlinear association between PDIs and sensory impairments. Results: Participants in the highest quintile of PDI exhibited reduced prevalence of VI (OR 0.78, 95% CI: 0.67–0.90, p_trend <0.001), HI (OR 0.83, 95% CI: 0.70–0.99, p_trend <0.001), and DSI (OR 0.62, 95% CI: 0.51–0.77, p_trend <0.001) relative to those in the lowest quintile. Moreover, individuals who ranked in the highest quintile for hPDI exhibited a 25% reduced risk of VI disease. Conversely, those in the highest quintile of uPDI were associated with increased prevalence of VI (OR 1.37, 95% CI: 1.17–1.61, p_trend <0.001), HI (OR 1.36, 95% CI: 1.12–1.65, p_trend <0.001), and DSI (OR 1.56, 95% CI: 1.25–1.95, p_trend <0.001). The relationship between PDIs increasing by every 10 units and sensory impairments showed similar patterns. Notably, hPDI demonstrated a nonlinear relationship with HI (p_{for nonlinearity} = 0.001), while the others exhibited linear associations. Conclusion: The increase in PDI and hPDI correlates with a reduced prevalence of one or more sensory impairments. Conversely, an increase in uPDI is associated with an elevated prevalence of multiple sensory impairments. Our study findings emphasize the significance of plant-based food quality, advocating for adherence to a plant-based dietary pattern while reducing the intake of less healthy plant foods and animal-based products.