How dietary habits and behaviors safeguard daily living activities among the elderly - novel insights from a decade-long longitudinal study

Rapid global population aging highlights the urgent need for targeted health recommendations to enhance the quality of life (QoL) for seniors and alleviate financial burdens. This study identifies key determinants of Basic Activities of Daily Living (BADL) among the Chinese elderly, focusing on dietary habits, daily behaviors, health status, and access to medical care. The data utilized in this study were derived from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Participants were selected from individuals initially followed in 2008 who remained alive through 2018. BADL were evaluated during the follow-up assessments conducted in the years 2008, 2011, 2014, and 2018. Participants were classified into two groups according to the variations observed in their BADL scores over a ten-year period: the ‘Immutable Type (IT)’ and the ‘Deteriorated Type (DT).’ Physical function was assessed using the Katz index, which includes six fundamental activities: bathing, dressing, toileting, indoor transferring, continence of defecation, and eating. Dietary intake was evaluated based on the frequency of consumption of various food groups and the specific types of foods ingested. The research employed univariate analysis to identify potential factors influencing physical functioning among the elderly. Propensity Score Matching (PSM) was utilized to balance for age and gender, followed by sensitivity analyses using four different models to ensure the robustness of the findings. A total of 2,350 participants were included in the analysis: comprising 1,666 individuals in the IT group and 684 in the DT group. The median age of participants in the stable group was 72 years, ranging from 62 to 103 years (n = 1666), while the median age of those in the deteriorating group was 78.0 years, ranging from 63 to 104 years (n = 684).The study found that a diet with rice as the staple food, engagement in housework, living alone, having lower systolic blood pressure, and the absence of a history of cardiovascular disease or stroke were significantly associated with maintaining stable BADL in the elderly. These factors were consistently identified across all sensitivity analysis models. The results suggest that specific dietary habits and lifestyle factors are linked to better physical functioning in older adults. The study’s findings can inform health guidance and interventions for the elderly, potentially contributing to increased healthy life years and reducing the financial burden on society. The use of PSM and multiple sensitivity analyses strengthens the reliability of the study’s conclusions.