碳水化合物质量与人类健康：一系列系统综述和荟萃分析

BACKGROUND 以前的系统评价和荟萃分析解释了碳水化合物质量与健康之间的关系，通常仅检查单个标志物和有限数量的临床结局。我们旨在更精确地量化几种标志物的预测潜力，确定哪些标志物最有用，并为定量推荐膳食纤维摄入量建立证据基础。

METHODS 我们对从数据库开始到2017年4月30日发布的前瞻性研究进行了一系列系统的回顾和荟萃分析，从数据库开始到2018年2月28日发布了随机对照试验，报告了碳水化合物质量和非传染性疾病的指标发病率，死亡率和危险因素。通过在PubMed，Ovid MEDLINE，Embase和对照试验的Cochrane中央登记册中进行搜索，以及通过手工搜索以前的出版物来鉴定研究。我们排除了前瞻性研究和报告慢性病参与者的试验，以及减肥试验或涉及补品的试验。搜索，数据提取和偏见评估独立重复。通过敏感性分析，Meta回归，剂量反应测试和亚组分析，考虑了随机效应模型中汇总估计的稳健性。 GRADE方法用于评估证据质量。

FINDINGS 分析包括来自185项前瞻性研究和58项针对4635名成年参与者的58项临床试验的不到1.35亿人年的数据。观察数据表明，与饮食摄入量最高的消费者和饮食摄入量最低的消费者相比，全因和心血管相关的死亡率以及冠心病，中风发生率和死亡率，2型糖尿病和结肠直肠癌的发病率降低了15-30％。与较高的膳食纤维摄入量相比，体重，收缩压和总胆固醇明显降低。当膳食纤维的日摄入量在25克至29克之间时，与一系列关键结果相关的风险降低最大。剂量-反应曲线表明，膳食纤维的摄入量更高，可以为心血管疾病，2型糖尿病以及结直肠癌和乳腺癌提供更大的益处。观察到全谷物摄入量相似的发现。在比较以低血糖指数或高血糖指数或高负荷饮食为特征的饮食效果时，通过观察数据发现风险降低的幅度较小或没有。碳水化合物质量与关键结局之间关系的证据确凿度为：膳食纤维为中度，全谷类为低至中度，饮食血糖指数和血糖负荷为低至极低。与其他饮食接触有关的数据很少。

INTERPRETATION 前瞻性研究和临床试验的结果与膳食纤维和全谷物的相对较高摄入量是互补的，并且惊人的剂量反应证据表明，与几种非传染性疾病的关系可能是因果关系。实施建议以增加膳食纤维的摄入量，并用全谷物代替精制谷物有望对人类健康有益。这项研究的主要优势是能够从一项队列研究和一项随机研究中，检查与一系列非传染性疾病结果相关的碳水化合物质量的关键指标。我们的发现仅限于降低总体风险，而不是减少患有慢性病的人群。

FUNDING 新西兰卫生研究委员会，世界卫生组织，Riddet卓越研究中心，健康者生命科学挑战赛，奥塔哥大学和奥塔哥南国糖尿病研究基金会。

Carbohydrate quality and human health: a series of systematic reviews and meta-analyses.
Reynolds A,et al Lancet 2019 02 02
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Abstract
翻译

BACKGROUND 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.
METHODS 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. 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. 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.
FINDINGS 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. 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. 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.
INTERPRETATION 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. 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.
FUNDING Health Research Council of New Zealand, WHO, Riddet Centre of Research Excellence, Healthier Lives National Science Challenge, University of Otago, and the Otago Southland Diabetes Research Trust.