The effect of whole grain intake on biomarkers of subclinical inflammation: a comprehensive meta-analysis of randomized controlled trials

Background and Objective: Findings on the effect of whole grain (WG) consumption on inflammatory biomarkers are conflicting. We aimed to summarize studies on the effects of WG consumption on inflammatory biomarkers in adults. Materials and Methods: Online databases were searched for relevant studies published up to Jan 2018, using relevant keywords. We included randomized clinical trials (RCTs) investigating the effect of WG foods or diets high in WG foods on markers of inflammation. Studies were selected if they had a control diet low in WGs or diets without WGs, 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. Findings: Overall, 14 RCTs, with 1238 individuals aged > =18 y, were included. Pooling 13 effect sizes from 11 RCTs on C-reactive protein (CRP) concentrations, we found no significant effect of WG consumption on serum CRP concentrations. We found no significant effect of WG consumption on serum IL-6 concentrations. Such a non-significant effect of WG intake on circulating TNF-α concentrations was also seen. Conclusion: Unlike observational studies, we found no significant effect of WG consumption on serum levels of inflammatory cytokines, including CRP, IL-6, and TNF-α.

کلیدواژه ها:

Whole grains ، inflammation ، meta-analysis ، clinical trials