荟萃分析发现：红肉不会带来心脑血管疾病

　　在过去的20年里，营养餐单总是建议大家少吃红肉。少吃红肉取决于是否有心血管疾病，既往研究称红肉与心脑血管疾病有关，然而却不能证明是红肉引起的心脑血管疾病。

　　2016年11月23日，美国营养学会官方期刊《美国临床营养杂志》在线发表普渡大学的研究报告，建议可以把红肉列入健康食谱中，因为红肉不仅营养丰富，而且还是蛋白质和铁的重要来源。

　　该研究从PubMed、Cochrane、Scopus数据库系统检索出945项研究，从中筛选出24项符合标准的随机对照研究，荟萃分析了心脑血管疾病的风险因素。

　　结果发现，每天红肉摄入量≥35g与＜35g相比，对血压、胆固醇、高密度脂蛋白、低密度脂蛋白、甘油三酯水平无显著不良影响。

　　该研究包括各种红肉，尤其是牛肉和猪肉。

　　血压和胆固醇并不是引起心脑血管疾病的唯一根源，进一步研究正在进行中，所需时间长短几周、几个月不定，来观察人们几年，或者长达几十年的心脑血管疾病的成因。研究者还将重点找出引起心脑血管疾病的潜在因素。

Am J Clin Nutr. 2016 Nov 23. [Epub ahead of print]

Total red meat intake of ≥0.5 servings/d does not negatively influence cardiovascular disease risk factors: a systemically searched meta-analysis of randomized controlled trials.

O'Connor LE, Kim JE, Campbell WW.

Department of Nutrition Science, Purdue University, West Lafayette, IN.

BACKGROUND: Observational associations between red meat intake and cardiovascular disease (CVD) are inconsistent. There are limited comprehensive analyses of randomized controlled trials (RCTs) that investigate the effects of red meat consumption on CVD risk factors.

OBJECTIVE: The purpose of this systematically searched meta-analysis was to assess the effects of consuming ≥0.5 or <0.5 servings of total red meat/d on CVD risk factors [blood total cholesterol (TC), LDL cholesterol, HDL cholesterol, triglycerides, ratio of TC to HDL cholesterol (TC:HDL), and systolic and diastolic blood pressures (SBP and DBP, respectively)]. We hypothesized that the consumption of ≥0.5 servings of total red meat/d would have a negative effect on these CVD risk factors.

DESIGN: Two researchers independently screened 945 studies from PubMed, Cochrane Library, and Scopus databases and extracted data from 24 qualified RCTs. Inclusion criteria were 1) RCT, 2) subjects aged ≥19 y, 3) consumption of ≥0.5 or <0.5 total red meat servings/d [35 g (1.25 ounces)], and 4) reporting ≥1 CVD risk factor. We performed an adjusted 2-factor nested ANOVA mixed-effects model procedure on the postintervention values of TC, LDL cholesterol, HDL cholesterol, TC:HDL cholesterol, triglycerides, SBP, and DBP; calculated overall effect sizes of change values; and used a repeated-measures ANOVA to assess pre- to postintervention changes.

RESULTS: Red meat intake did not affect lipid-lipoprotein profiles or blood pressure values postintervention (P > 0.05) or changes over time [weighted mean difference (95% CI): -0.01 mmol/L (-0.08, 0.06 mmol/L), 0.02 mmol/L (-0.05, 0.08 mmol/L), 0.03 mmol/L (-0.01, 0.07 mmol/L), and 0.04 mmol/L (-0.02, 0.10 mmol/L) mmol/L; -0.08 mm Hg (-0.26, 0.11 mm Hg); and -1.0 mm Hg (-2.4, 0.78 mm Hg) and 0.1 mm Hg (-1.2, 1.5 mm Hg) for TC, LDL cholesterol, HDL cholesterol, triglycerides, TC:HDL cholesterol, SBP, and DBP, respectively]. Among all subjects, TC, LDL cholesterol, HDL cholesterol, TC:HDL cholesterol, triglycerides, and DBP, but not SBP, decreased over time (P < 0.05).

CONCLUSIONS: The results from this systematically searched meta-analysis of RCTs support the idea that the consumption of ≥0.5 servings of total red meat/d does not influence blood lipids and lipoproteins or blood pressures.

KEYWORDS: animal flesh; blood lipids; blood lipoproteins; blood pressure; diet; dietary guidance; meat; meat products

PMID: 27881394

PII: ajcn142521

DOI: 10.3945/ajcn.116.142521