 Carbohydrate quality and human health: a series of systematic reviews and meta-analyses
Background 背景 Previous systematic reviews and meta-analyses explaining the relationship between carbohydrate quality and health have usually examined a single marker and a limited number of clinical outcomes. We aimed to more precisely quantify the predictive potential of several markers, to determine which markers are most useful, and to establish an evidence base for quantitative recommendations for intakes of dietary fibre. 以往解释碳水化合物质量和健康之间的关系的系统回顾和荟萃分析，通常只测试了一种标记物并且临床结果有限。我们的目标是更精确地量化几种标记物的预测潜力，以确定哪些标记物最有用，并为膳食纤维摄入量的定量建议建立循证基础。 Methods 方法 We did a series of systematic reviews and meta-analyses of prospective studies published from database inception to April 30, 2017, and randomised controlled trials published from database inception to Feb 28, 2018, which reported on indicators of carbohydrate quality and non-communicable disease incidence, mortality, and risk factors. 我们对从数据库建立至2017年4月30日期间发表的前瞻性研究，和从数据库建立到2018年2月28日期间发表的随机对照试验进行了一系列系统性回顾和荟萃分析，这些试验报告了碳水化合物质量和非传染性疾病发病率、死亡率以及危险因素的指标。 Studies were identified by searches in PubMed, Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials, and by hand searching of previous publications. We excluded prospective studies and trials reporting on participants with a chronic disease, and weight loss trials or trials involving supplements. Searches, data extraction, and bias assessment were duplicated independently. 我们通过检索PubMed、Ovid MEDLINE、Embase和the Cochrane Central Register of Controlled Trials，以及翻阅检索以前的出版物，确定了研究。我们排除了对患有慢性疾病的参与者的前瞻性研究和试验报告，以及减肥试验或包含有补充营养的试验。我们对这些研究分别进行重复搜索、数据提取和偏差评估。 Robustness of pooled estimates from random-effects models was considered with sensitivity analyses, meta-regression, dose-response testing, and subgroup analyses. The GRADE approach was used to assess quality of evidence. 通过敏感性分析、元回归、剂量反应测试和亚组分析，考量了随机效应模型的合并估计的稳健性。采用GRADE法来评价证据质量。 Findings 发现 Just under 135 million person-years of data from 185 prospective studies and 58 clinical trials with 4635 adult participants were included in the analyses. Observational data suggest a 15–30% decrease in all-cause and cardiovascular related mortality, and incidence of coronary heart disease, stroke incidence and mortality, type 2 diabetes, and colorectal cancer when comparing the highest dietary fibre consumers with the lowest consumers. Clinical trials show significantly lower bodyweight, systolic blood pressure, and total cholesterol when comparing higher with lower intakes of dietary fibre. 来自185项前瞻性研究和58项包括4635名成年受试者的临床试验的共计近1.35亿人年的数据被纳入分析。观察数据显示，与膳食纤维摄入量最高的人群相比，膳食纤维摄入量最低的人群的全因和心血管相关死亡率、冠心病发病率、中风发病率和死亡率、2型糖尿病和结肠直肠癌发病率下降了15-30%。临床试验表明，与膳食纤维摄入量较低的人相比，食用纤维摄入量较高的人体重、收缩压和总胆固醇明显较低。 Risk reduction associated with a range of critical outcomes was greatest when daily intake of dietary fibre was between 25 g and 29 g. Dose-response curves suggested that higher intakes of dietary fibre could confer even greater benefit to protect against cardiovascular diseases, type 2 diabetes, and colorectal and breast cancer. Similar findings for whole grain intake were observed. Smaller or no risk reductions were found with the observational data when comparing the effects of diets characterised by low rather than higher glycaemic index or load. 当每日膳食纤维摄入量在25克至29克之间时，与一系列重要疾病相关的风险降低幅度最大。剂量-反应曲线表明，摄入更多膳食纤维，对预防心血管疾病、2型糖尿病、结肠直肠癌和乳腺癌有更大的益处。在全谷物摄入量方面也观察到类似的结果。在比较以低血糖指数而非高血糖指数或负荷为特征的饮食的效果时，观察数据显示，其降低的风险较小或没有降低。 The certainty of evidence for relationships between carbohydrate quality and critical outcomes was graded as moderate for dietary fibre, low to moderate for whole grains, and low to very low for dietary glycaemic index and glycaemic load. Data relating to other dietary exposures are scarce. 碳水化合物质量和重要结果（疾病相关）之间关系的确切程度，被划分为膳食纤维适度、全谷物低至中度、膳食血糖指数和血糖负荷低至极低。其他饮食相关暴露的数据很少。 Interpretation 解释 Findings from prospective studies and clinical trials associated with relatively high intakes of dietary fibre and whole grains were complementary, and striking dose-response evidence indicates that the relationships to several non-communicable diseases could be causal. Implementation of recommendations to increase dietary fibre intake and to replace refined grains with whole grains is expected to benefit human health. 膳食纤维和全谷物的相对高摄入量相关的前瞻性研究和临床试验的结果也相辅相成，并且明显的剂量反应证据表明，该摄入量与若干非传染性疾病可能是因果关系。遵循增加膳食纤维摄入量和用全谷物代替精制谷物的建议将有益于人类健康。 A major strength of the study was the ability to examine key indicators of carbohydrate quality in relation to a range of non-communicable disease outcomes from cohort studies and randomised trials in a single study. Our findings are limited to risk reduction in the population at large rather than those with chronic disease. 这项研究的一个主要亮点在于，它能够从一项研究中对队列研究和随机试验中一系列与非传染性疾病结果相关的碳水化合物质量的关键指标进行检测。我们的发现仅限于降低总体人群的发病风险，而非慢性病患者。 （此文为转载） |
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