Table 1_Maintaining long-term frequent tea consumption could reduce the risk of cognitive decline: results from a 10-year longitudinal study.docx

BackgroundPrevious studies have suggested that tea may have neuroprotective effect. This study aimed to investigate the association between tea consumption frequency and cognitive decline, taking into account changes in consumption habits and selection bias.
MethodsThis study used data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) in 2008, 2011, 2014, and 2018 years. Changes in tea consumption habits were identified based on the frequency and consistency of tea consumption at baseline and at the last follow-up. Cognitive function was assessed by using Mini-Mental State Examination (MMSE). Cox proportional hazards models were conducted to estimate association between tea consumption habits and cognitive decline. Inverse probability of treatment weighting (IPTW) was applied to reduce selection bias.
ResultsConsistently frequent tea consumption reduced the risk of cognitive decline, whereas inconsistently frequent tea consumption did not. Compared with consistently infrequent tea drinkers, the multivariable-adjusted HR of cognitive decline was 0.98 (95% CI: 0.90, 1.06) for inconsistently frequent tea drinkers, and 0.86 (95% CI: 0.76, 0.96) for consistently frequent tea drinkers. With increasing frequency of tea consumption, the risk of developing cognitive decline decreased (P for trend: 0.023). Similarly, the association remained robust after IPTW adjustment. Consistently frequent tea drinkers had a 12% (HR:0.88, 95% CI: 0.77, 0.99) reduced risk of cognitive decline, whereas no significant association was observed for inconsistently frequent tea consumption (HR:0.98, 95% CI:0.91, 1.07) (P for trend < 0.001). Additionally, frequent consumption of both tea and fruit has a synergistic effect on cognitive health (P for interaction = 0.041).
ConclusionMaintaining an uninterrupted habit of frequent tea consumption over time could reduce the risk of cognitive decline, whereas inconsistently frequent tea consumption was not significant, even after IPTW adjustment. Regular consumption of tea and fruit has a synergistic effect on cognitive health.

研究背景
既往研究表明，茶叶可能具有神经保护作用。本研究旨在探讨饮茶频率与认知衰退之间的关联，并考量饮茶习惯变化与选择偏倚的影响。

研究方法
本研究采用2008、2011、2014及2018年中国纵向健康长寿调查（Chinese Longitudinal Healthy Longevity Survey, CLHLS）的数据。基于基线与末次随访时的饮茶频率及持续性，判定饮茶习惯的变化情况。采用简易精神状态检查表（Mini-Mental State Examination, MMSE）评估认知功能。通过Cox比例风险模型估算饮茶习惯与认知衰退的关联，并运用治疗加权逆概率（Inverse Probability of Treatment Weighting, IPTW）校正以减少选择偏倚。

研究结果
持续规律饮茶可降低认知衰退风险，而间断性规律饮茶则无此关联。与持续少量饮茶者相比，间断性规律饮茶者的多变量校正后认知衰退风险比（Hazard Ratio, HR）为0.98（95%置信区间：0.90~1.06），持续规律饮茶者为0.86（95%置信区间：0.76~0.96）。随着饮茶频率升高，认知衰退风险呈显著下降趋势（趋势检验P=0.023）。经IPTW校正后，上述关联仍保持稳健。持续规律饮茶者的认知衰退风险降低12%（HR=0.88，95%置信区间：0.77~0.99），而间断性规律饮茶者未观察到显著关联（HR=0.98，95%置信区间：0.91~1.07，趋势检验P<0.001）。此外，规律饮茶与规律食用水果对认知健康存在协同保护作用（交互作用P=0.041）。

研究结论
长期保持持续规律的饮茶习惯可降低认知衰退风险；即便经IPTW校正后，间断性规律饮茶仍未显示出显著的认知保护作用。规律饮茶与食用水果对认知健康具有协同保护效应。