Division of Nephrology, Nanfang Hospital, Southern Medical University; National Clinical Research Center for Kidney Disease; State Key Laboratory of Organ Failure Research; Guangdong Provincial Institute of Nephrology, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, Guangdong 510515, China.
Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui 230032, China.
Age Ageing. 2024 Jan 2;53(1). doi: 10.1093/ageing/afae008.
The prospective association between dietary zinc (Zn) intake and cognitive decline remains uncertain. We aimed to assess the relationship of dietary Zn intake with the risk of cognitive decline in the Chinese older people, and examine the possible effect modifiers on this association.
A total of 3,106 older Chinese adults aged 55 years or older from China Health and Nutrition Survey were included. Dietary nutrients intake information was collected by combined 24-h dietary recalls with weighing food inventory. The cognitive decline was defined as the 5-year decline rate in global and composite cognitive scores, based on a subset of items from the Telephone Interview for Cognitive Status-modified.
The median follow-up duration was 5.9 years. There was an L-shaped association between dietary Zn intake and the 5-year decline rates in global and composite cognitive scores, with an inflection point at 8.8 mg/day of dietary Zn. For the composite cognitive scores, compared with the first quantile (<7.9 mg/day) of dietary Zn intake, quantiles 2-6 (≥7.9 mg/day) had a significantly slower cognitive decline rate (β: -0.24; 95% confidence interval: -0.40 to -0.07). Similar results were found for the global cognitive scores. Moreover, the inverse association between dietary Zn intake and cognitive decline in composite cognitive scores was significantly stronger in those with lower levels of physical activity (P-interactions = 0.041).
Dietary Zn intake was negatively associated with cognitive decline in the older people. Maintaining appropriate dietary Zn levels may prevent cognitive decline.
膳食锌（Zn）摄入与认知能力下降之间的前瞻性关联尚不确定。我们旨在评估中国老年人膳食 Zn 摄入量与认知能力下降风险之间的关系，并研究可能对这种关联产生影响的修饰因素。
共有 3106 名年龄在 55 岁及以上的中国老年人参与了中国健康与营养调查。通过 24 小时膳食回顾与称重食物清单相结合的方式收集膳食营养素摄入量信息。认知能力下降定义为全球和综合认知评分的 5 年下降率，基于电话访谈认知状态修改版的一部分项目。
中位随访时间为 5.9 年。膳食 Zn 摄入量与全球和综合认知评分的 5 年下降率之间呈 L 形关联，转折点为 8.8 毫克/天的膳食 Zn。对于综合认知评分，与膳食 Zn 摄入量的第一分位数（<7.9 毫克/天）相比，分位值 2-6（≥7.9 毫克/天）的认知下降速度明显较慢（β：-0.24；95%置信区间：-0.40 至 -0.07）。对于全球认知评分也得到了类似的结果。此外，在体力活动水平较低的人群中，膳食 Zn 摄入与综合认知评分下降之间的负相关关系更强（P 交互 = 0.041）。
膳食 Zn 摄入与老年人的认知能力下降呈负相关。保持适当的膳食 Zn 水平可能有助于预防认知能力下降。
