适当增加全谷物摄入可降低多种疾病风险和死亡风险
近年来，随着人们对麸质的恐惧越来越强烈，谷物的摄入急剧减少。许多人或许无法耐受麸质，但是最新研究结果提示，应增加全谷物的摄入。
2016年6月14日，《英国医学杂志》发表挪威科技大学、伦敦帝国学院、哈佛大学陈曾熙公共卫生学院、哈佛大学医学院、波士顿布莱根女子医院、挪威卑尔根大学、纽约西奈山伊坎医学院、英国利兹大学、挪威奥斯陆大学的系统回顾与量效荟萃分析，共纳入45项前瞻性研究的64篇已发表文章，评估了全谷物或特定类型谷物摄入与心血管疾病、所有癌症、全因和特因死亡率的相关性。
结果发现，每日摄入3份全谷物（90g，相当于全谷物制成的2片面包和1碗麦片，或1.5片皮塔面包），冠心病、卒中、心血管疾病的平均相对风险分别下降19%、12%、22%，所有癌症、全因、呼吸疾病、糖尿病、感染疾病、所有非心血管非癌症原因的死亡率平均相对风险分别下降15%、17%、22%、51%、26%、22%。每日全谷物摄入最高达到210～225g（即每日7～7.5份全谷物）时，仍可见大多数结局风险下降。此外，即使在校正混杂变量（包括体重指数、吸烟和体力活动）后，全谷物食物的这些健康获益仍持续存在。
该研究主要针对全谷物（包括全麦面包、全麦早餐麦片）的健康获益，而非加工过的谷物。进食加工过的谷物（包括白米饭）并无任何健康获益。加工过的谷物主要由糖类组成，相比之下，全谷物含有糖类、纤维、矿物质和维生素。
因此，增加全谷物摄入有助于降低冠心病、卒中、心血管疾病的风险以及癌症、全因、呼吸疾病、感染疾病、糖尿病、所有非心血管非癌症原因的死亡风险。临床医师在与患者讨论饮食建议时应当传达这条信息。即使无法耐受麸质，也应鼓励患者进食全谷物。谷物中富含多种健康营养素，不应对其感到恐惧。当然，增加全谷物摄入应适可而止，因为限制热量摄入对健康也有益。
BMJ. 2016 Jun 14;353:i2716.
Whole grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-response meta-analysis of prospective studies.
Aune D, Keum N, Giovannucci E, Fadnes LT, Boffetta P, Greenwood DC, Tonstad S, Vatten LJ, Riboli E, Norat T.
Norwegian University of Science and Technology, Trondheim, Norway; Imperial College London, London, UK; Harvard T H Chan School of Public Health, Boston, MA, USA; Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA; University of Bergen, Bergen, Norway; The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; University of Leeds, Leeds, UK; Oslo University Hospital Ulleval, Oslo, Norway.
OBJECTIVE: To quantify the dose-response relation between consumption of whole grain and specific types of grains and the risk of cardiovascular disease, total cancer, and all cause and cause specific mortality.
DATA SOURCES: PubMed and Embase searched up to 3 April 2016.
STUDY SELECTION: Prospective studies reporting adjusted relative risk estimates for the association between intake of whole grains or specific types of grains and cardiovascular disease, total cancer, all cause or cause specific mortality.
DATA SYNTHESIS: Summary relative risks and 95% confidence intervals calculated with a random effects model.
RESULTS: 45 studies (64 publications) were included. The summary relative risks per 90 g/day increase in whole grain intake (90 g is equivalent to three servings-for example, two slices of bread and one bowl of cereal or one and a half pieces of pita bread made from whole grains) was 0.81 (95% confidence interval 0.75 to 0.87; I(2)=9%, n=7 studies) for coronary heart disease, 0.88 (0.75 to 1.03; I(2)=56%, n=6) for stroke, and 0.78 (0.73 to 0.85; I(2)=40%, n=10) for cardiovascular disease, with similar results when studies were stratified by whether the outcome was incidence or mortality. The relative risks for morality were 0.85 (0.80 to 0.91; I(2)=37%, n=6) for total cancer, 0.83 (0.77 to 0.90; I(2)=83%, n=11) for all causes, 0.78 (0.70 to 0.87; I(2)=0%, n=4) for respiratory disease, 0.49 (0.23 to 1.05; I(2)=85%, n=4) for diabetes, 0.74 (0.56 to 0.96; I(2)=0%, n=3) for infectious diseases, 1.15 (0.66 to 2.02; I(2)=79%, n=2) for diseases of the nervous system disease, and 0.78 (0.75 to 0.82; I(2)=0%, n=5) for all non-cardiovascular, non-cancer causes. Reductions in risk were observed up to an intake of 210-225 g/day (seven to seven and a half servings per day) for most of the outcomes. Intakes of specific types of whole grains including whole grain bread, whole grain breakfast cereals, and added bran, as well as total bread and total breakfast cereals were also associated with reduced risks of cardiovascular disease and/or all cause mortality, but there was little evidence of an association with refined grains, white rice, total rice, or total grains.
CONCLUSIONS: This meta-analysis provides further evidence that whole grain intake is associated with a reduced risk of coronary heart disease, cardiovascular disease, and total cancer, and mortality from all causes, respiratory diseases, infectious diseases, diabetes, and all non-cardiovascular, non-cancer causes. These findings support dietary guidelines that recommend increased intake of whole grain to reduce the risk of chronic diseases and premature mortality.
PMID: 27301975
PMCID: PMC4908315
DOI: 10.1136/bmj.i2716
