Food Security Research Center, Department of Community Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran.
Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Adv Nutr. 2020 Jan 1;11(1):52-65. doi: 10.1093/advances/nmz063.
Findings on the effect of whole-grain consumption on inflammatory biomarkers are conflicting. This study aimed to summarize available studies on the effects of whole-grain consumption on inflammatory biomarkers in adults. Online databases including PubMed, Scopus, ISI Web of Science, and Google Scholar were searched for relevant studies published up to January 2018, using relevant keywords. We included randomized controlled trials (RCTs) investigating the effect of whole-grain foods or diets high in whole-grain foods on markers of inflammation. Studies were selected if they had a control diet low in whole grains or diets without whole grains, whether calorie restricted or not. We did not include studies that examined the effect of individual grain components, including bran or germ, or fiber-based diets. Overall, 14 RCTs, with 1238 individuals aged ≥18 y, were included. Pooling 13 effect sizes from 11 RCTs on serum C-reactive protein (CRP) concentrations, we found no significant effect of whole-grain consumption on serum CRP concentrations [weighted mean difference (WMD): -0.29 mg/L; 95% CI: -1.10, 0.52 mg/L]. However, the beneficial effects of whole-grain intake on serum CRP concentrations were observed in studies in individuals with elevated serum concentrations of CRP and studies with isocaloric diets. Combining 11 effect sizes from 10 RCTs, we found no significant effect of whole-grain consumption on serum IL-6 concentrations (WMD: -0.08 pg/mL; 95% CI: -0.27, 0.11 pg/mL). Nevertheless, we observed a significant effect of whole-grain consumption on serum IL-6 concentrations in studies in unhealthy individuals. A nonsignificant effect of whole-grain intake on circulating serum TNF-α concentrations was also seen when we summarized effect sizes from 7 RCTs (WMD: -0.06 pg/mL; 95% CI: -0.25, 0.14 pg/mL). Such a nonsignificant effect was observed for serum concentrations of plasminogen activator inhibitor-1 (PAI-1) (WMD: -3.59; 95% CI: -1.25, 8.44 kU/L). Unlike observational studies, we found no significant effect of whole-grain consumption on serum concentrations of inflammatory cytokines, including serum concentrations of CRP, IL-6, TNF-α, and PAI-1. However, beneficial effects of whole grains were found in some subgroups. Given the high between-study heterogeneity, deriving firm conclusions is difficult.
关于全谷物消费对炎症生物标志物影响的研究结果存在矛盾。本研究旨在总结目前关于全谷物消费对成年人炎症生物标志物影响的研究。使用相关关键词，检索了 PubMed、Scopus、ISI Web of Science 和 Google Scholar 等在线数据库，以获取截至 2018 年 1 月的相关研究。我们纳入了研究全谷物食品或高膳食纤维食品对炎症标志物影响的随机对照试验（RCT）。如果对照饮食中全谷物含量低或不含全谷物，无论是否限制热量，我们都会选择这些研究。我们不包括研究个别谷物成分（包括糠或胚芽）或纤维饮食对炎症生物标志物影响的研究。共有 14 项 RCT，涉及 1238 名年龄≥18 岁的成年人。综合 11 项 RCT 的 13 个血清 C 反应蛋白（CRP）浓度的效应量，我们发现全谷物消费对血清 CRP 浓度无显著影响[加权均数差（WMD）：-0.29mg/L；95%置信区间（CI）：-1.10，0.52mg/L]。然而，在 CRP 血清浓度升高的个体和热量相等的饮食研究中，观察到全谷物摄入对血清 CRP 浓度的有益影响。综合 10 项 RCT 的 11 个效应量，我们发现全谷物消费对血清白细胞介素 6（IL-6）浓度无显著影响[WMD：-0.08pg/mL；95%CI：-0.27，0.11pg/mL]。然而，我们观察到在不健康个体的研究中，全谷物消费对血清 IL-6 浓度有显著影响。当综合 7 项 RCT 的效应量时，我们也观察到全谷物摄入对循环血清肿瘤坏死因子-α（TNF-α）浓度无显著影响[WMD：-0.06pg/mL；95%CI：-0.25，0.14pg/mL]。这种无显著影响也见于纤溶酶原激活物抑制剂-1（PAI-1）的血清浓度[WMD：-3.59；95%CI：-1.25，8.44kU/L]。与观察性研究不同，我们发现全谷物消费对炎症细胞因子（包括 CRP、IL-6、TNF-α 和 PAI-1 的血清浓度）无显著影响。然而，在一些亚组中发现了全谷物的有益作用。由于研究间存在高度异质性，很难得出明确的结论。
