EffectsofDietaryPatternsonBiomarkersof InflammationandImmuneResponses: ASystematicReviewandMeta-Analysisof RandomizedControlledTrials

Abstract

Altered immune cell phenotype and chronic inflammation are key features shared by various chronic diseases. Evidence from nutritional interventions aimed at alleviating inflammation could be a promising approach for the prevention of adverse health outcomes. We therefore aimed to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to summarize the recent evidence on the effects of dietary patterns on inflammatory and immune-related biomarkers in humans. PubMed, Medline, and Web of Science databases were searched for publications up to October 2020. In total, 22 RCTs were included in the meta-analysis conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Mediterranean diet appeared as the dietary pattern that showed the most prominent reductionsofinflammatorybiomarkerssuchasIL-6[meandifference(MD):–1.07pg/mL(95%CI:–1.94,–0.20);I2:96%],IL-1β [MD:–0.46pg/mL(95% CI:–0.66,–0.25);I2:0%],andC-reactiveprotein[MD:–1.00mg/L(95%CI:–2.02,0.01);I2:100%].Nosubstantialeffectswereobservedfortheadditional dietary patterns studied in intervention research, including the Dietary Adherence to Stop Hypertension diet, and the vegetarian or vegan diets. Future large-scale multifactorial intervention studies are warranted to allow direct comparison of various dietary patterns in relation to a range of biomarkersreflectingmultipleinflammatoryandimmune-relatedpathways