Dietary diversity and frailty among older Chinese people: evidence from the Chinese Longitudinal Healthy Longevity Study.

Background: Dietary diversity is widely advocated as a means to promote health, but little is known regarding whether the beneficial effects still apply in older adults.

Objective: To examine the association between the dietary diversity score (DDS) and frailty among older Chinese adults.

Methods: A total of 13,721 adults aged ≥65 y without frailty at baseline were enrolled. The DDS at baseline was constructed based on 9 items of a food frequency questionnaire. We used 39 self-reported health items to construct a frailty index (FI), with FI ≥ 0.25 indicating frailty. Cox models with restricted cubic splines were used to evaluate the dose-response relationships of DDS (continuous) with frailty. In addition, Cox proportional hazard models were used to examine the association between DDS (categorized as scores ≤4, 5-6, 7, and ≥8) and frailty.

Results: During the mean follow-up of 5.94 y, 5250 participants met the criteria for frailty. Each 1-unit increase in DDS corresponded to a 5% lower risk of frailty (hazard ratio [HR]; 0.95; 95% CI: 0.94, 0.97]. Compared with participants with DDS ≤4 points, those with a DDS of 5-6, 7, and ≥8 points exhibited a lower frailty risk, with HRs of 0.79 (95% CI: 0.71, 0.87), 0.75 (95% CI: 0.68, 0.83), and 0.74 (95% CI: 0.67, 0.81), respectively (P-trend < 0.001). Protein-rich food items, such as meat; eggs; and beans, were associated with protective effects against frailty. In addition, a significant association was observed between higher consumption of 2 high-frequency foods, tea and fruits, and lower risk of frailty.

Conclusions: A higher DDS was associated with a lower risk of frailty among older Chinese adults. This study highlights the importance of a diverse diet as a potential modifiable behavioral factor for preventing frailty in older Chinese adults.