Division of Epidemiology, Department of Health Informatics and Public Health, School of Public Health, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
Division of Epidemiology, Department of Health Informatics and Public Health, School of Public Health, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
Clin Nutr. 2021 May;40(5):3495-3502. doi: 10.1016/j.clnu.2020.11.036. Epub 2020 Dec 5.
BACKGROUND & AIMS: Previous studies have reported that the Japanese diet is associated with a lower risk of dementia; however, whether changes in adherence to the Japanese diet affects incident dementia remains unknown. We aimed to evaluate the association between long-term changes in adherence to the Japanese diet and risk of incident dementia among older Japanese individuals.
We collected dietary information from community-dwelling older individuals living in Ohsaki city, Japan using a validated 39-item food frequency questionnaire in 1994 and 2006. Adherence to the Japanese diet was assessed using the 8-item Japanese Diet Index (JDI8) score (range: 0 to 8 points). Changes in adherence to the Japanese diet were defined as changes in the JDI8 score from 1994 to 2006. Next, the participants were classified into five groups: great decrease, moderate decrease, no changes [ref.], moderate increase, or great increase. Then, 3146 Japanese adults aged ≥65 years in 2006 were followed-up for 5.7 years. Incident dementia was retrieved from the long-term care insurance database. The Cox proportional hazards model was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for incident dementia.
During 14,336 person-years of follow up, 231 cases of dementia were ascertained. Compared with no changes in the JDI8 score, the multivariable-adjusted HRs (95%CIs) were 1.72 (1.13, 2.62) for great decrease, 1.10 (0.73, 1.66) for moderate decrease, 0.82 (0.54, 1.25) for moderate increase, and 0.62 (0.38, 1.02) for great increase (p-trend <0.0001).
An increase in adherence to the Japanese diet was associated with a reduced risk of incident dementia, whereas a decrease in adherence was associated with an elevated risk among older Japanese individuals.
既往研究报道，日本饮食与痴呆风险降低相关；然而，依从日本饮食模式的变化是否会影响痴呆的发生尚不清楚。我们旨在评估日本饮食依从性的长期变化与老年日本个体发生痴呆的风险之间的关系。
我们使用经过验证的 39 项食物频率问卷，于 1994 年和 2006 年在日本大崎市收集了社区居住的老年个体的饮食信息。采用 8 项日本饮食指数（JDI8）评分（范围：0 至 8 分）评估日本饮食的依从性。日本饮食依从性的变化定义为 1994 年至 2006 年 JDI8 评分的变化。然后，将参与者分为 5 组：大幅下降、中度下降、无变化[参考]、中度增加或大幅增加。然后，2006 年年龄≥65 岁的 3146 名日本成年人随访 5.7 年。痴呆事件从长期护理保险数据库中检索。采用 Cox 比例风险模型估计多变量校正后的风险比（HR）和 95%置信区间（95%CI）。
在 14336 人年的随访期间，确定了 231 例痴呆病例。与 JDI8 评分无变化相比，多变量校正后的 HR（95%CI）分别为：大幅下降组为 1.72（1.13，2.62）、中度下降组为 1.10（0.73，1.66）、中度增加组为 0.82（0.54，1.25）、大幅增加组为 0.62（0.38，1.02）（趋势检验 P<0.0001）。
日本饮食依从性的增加与发生痴呆的风险降低相关，而依从性下降与老年日本个体发生痴呆的风险升高相关。
