In the Women’s Health Initiative Dietary Modification randomized trial, the dietary intervention reduced breast cancer mortality by 21% ( = .02) and increased physical activity as well. Therefore, the aim was to examine whether or not these lifestyle changes attenuated age-related physical functioning decline. In a randomized trial, the influence of 8 years of a low-fat dietary pattern intervention was examined through 20 years of cumulative follow-up. From 1993 to 1998, 48,835 postmenopausal women, ages 50 to 79 years with no prior breast cancer and negative baseline mammogram were randomized at 40 US clinical centers to dietary intervention or usual diet comparison groups (40 out of 60). The intervention significantly reduced fat intake and increased vegetable, fruit, and grain intake. In post hoc analyses, physical functioning, assessed using the RAND 36-Item Short Form Health Survey, evaluated quality or limitations of 10 hierarchical physical activities. Longitudinal physical functioning, reported against a disability threshold (when assistance in daily activities is required) was the primary study outcome. Semiparametric linear mixed effect models were used to contrast physical functioning trajectories by randomization groups. Physical functioning score, assessed 495,317 times with 11.0 (median) assessments per participant, was significantly higher in the intervention vs comparison groups through 12 years of cumulative follow-up ( = .001), representing a reduction in age-related functional decline. The intervention effect subsequently attenuated and did not delay time to the disability threshold. Among women in the dietary intervention vs comparison groups, aged 50 to 59 years, who were physically inactive at entry, a persistent, statistically significant, favorable influence on physical functioning with associated delay in crossing the disability threshold by approximately a year was seen ( value for interaction = .007). In the Women’s Health Initiative Dietary Modification randomized trial, a dietary intervention that significantly reduced breast cancer mortality also significantly reduced age-related functional decline through 12 years, which was attenuated with longer follow-up.

中文翻译：

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饮食干预对身体机能产生有利影响：妇女健康倡议随机饮食调整试验

在妇女健康倡议饮食调整随机试验中，饮食干预使乳腺癌死亡率降低了 21% (= .02)，并且还增加了体力活动。因此，目的是检查这些生活方式的改变是否减轻了与年龄相关的身体机能下降。在一项随机试验中，通过 20 年的累积随访来检验 8 年低脂饮食模式干预的影响。从 1993 年到 1998 年，48,835 名年龄在 50 岁到 79 岁之间、既往无乳腺癌且基线乳房 X 光检查呈阴性的绝经后妇女在 40 个美国临床中心被随机分为饮食干预组或常规饮食对照组（60 人中的 40 人）。该干预措施显着减少了脂肪摄入量，增加了蔬菜、水果和谷物摄入量。在事后分析中，使用兰德 36 项简短健康调查评估身体机能，评估 10 种分级身体活动的质量或局限性。主要研究结果是针对残疾阈值（日常活动需要帮助时）报告的纵向身体机能。使用半参数线性混合效应模型来对比随机分组的身体机能轨迹。经过 495,317 次评估，每位参与者的身体功能评分为 11.0（中位数），在 12 年的累积随访中，干预组的身体功能评分显着高于对照组 (= .001)，这表明与年龄相关的功能衰退有所减少。干预效果随后减弱，并没有延迟达到残疾阈值的时间。在饮食干预组中，年龄为 50 至 59 岁、在进入时缺乏身体活动的女性中，观察到对身体机能产生持续的、统计显着的有利影响，并且与跨越残疾阈值相关的延迟大约一年（值交互作用 = .007)。在妇女健康倡议饮食调整随机试验中，饮食干预不仅显着降低了乳腺癌死亡率，还显着减少了 12 年内与年龄相关的功能衰退，并且随着随访时间的延长，这种现象有所减弱。