Overview
As China’s population rapidly ages, identifying dietary factors that help preserve independence becomes urgent. A large longitudinal study of Chinese adults aged 65 and older examined how dietary diversity, measured by a dietary diversity score (DDS), relates to disability in activities of daily living (ADL). The findings show that a more varied diet is associated with a lower risk of losing independence in daily tasks such as bathing, dressing, and feeding.
What is DDS and why it matters for ADL
Dietary diversity score (DDS) reflects the range of food groups consumed regularly. In this study, DDS was calculated from nine common Chinese dietary items, excluding staple grains and oil because they are consumed daily by most people. Participants with higher DDS ate a broader array of foods, which is linked to better nutrient intake and potentially better muscle function and energy levels—key components in maintaining ADL performance as people age.
The study population and design
Researchers analyzed 17,464 Chinese adults aged 65 and older who were free of ADL disability at baseline. They followed participants for an average of 5.25 years and used Cox proportional hazards models to estimate the association between baseline DDS (divided into quartiles) and incident disability in ADL. Covariates included age, sex, residence, education, income, smoking, alcohol use, body mass index, number of teeth, denture use, and multimorbidity.
Key findings
During the follow-up, 10,750 participants developed ADL disability. Compared with the lowest DDS quartile, those in higher quartiles had progressively lower risks of ADL disability after full adjustment: 0.91 for the second quartile, 0.87 for the third, and 0.87 for the fourth quartile. The trend was statistically significant (P < 0.001). A dose–response pattern showed risk decreasing with higher DDS, plateauing around a DDS of eight or more.
When looking at individual foods, protein-rich items such as meat, eggs, and beans were linked to reduced ADL disability risk. Fresh vegetables and fruits also showed protective associations, underscoring the importance of plant-based components in daily functioning for older adults. Other items like fish, salted vegetables, garlic, and tea did not show the same independent protective effects after correcting for multiple tests.
Interpreting the findings
The study supports a growing body of evidence that a diverse diet supports healthy aging and functional independence. Several mechanisms may explain the DDS-ADL link: adequate protein helps prevent sarcopenia and preserves muscle strength; fruits and vegetables supply antioxidants and minerals that promote muscle and bone health; and overall dietary variety may improve energy balance and reduce inflammation—factors linked to fewer disabilities in daily activities.
Public health implications
With China’s elderly population expanding rapidly, promoting dietary diversity could become a practical strategy to reduce ADL disability and its associated healthcare needs. Public health programs could focus on increasing access to a variety of protein sources, fruits, and vegetables for older adults, particularly in rural or under-resourced regions. Education for older adults and caregivers about the benefits of a varied diet may also help sustain independence and quality of life.
Strengths and limitations
The study’s strengths include its large, nationwide sample and long follow-up, with comprehensive adjustment for confounders. Limitations include reliance on self-reported dietary data and lack of detailed quantitative intake, which means energy intake could not be fully accounted for. Nonetheless, the DDS captured long-term dietary patterns and demonstrated a robust association with ADL disability risk.
Conclusion
The research indicates that higher dietary diversity is associated with a lower risk of disability in ADL among older Chinese adults. Encouraging a diverse diet—especially increased intake of protein-rich foods, vegetables, and fruits—may be a feasible and impactful approach to promote independent aging and reduce the burden of disability in daily living.
