Dietary Patterns Associated With Anti-inflammatory Effects: An Umbrella Review of Systematic Reviews and Meta-analyses.

Context: Noncommunicable diseases significantly impact global health, and chronic inflammation is a common pathological feature of these conditions. The relationship between chronic inflammation and dietary intake is increasingly evident, as emerging research elucidates the inflammation-modulating effects of diet.

Objective: This umbrella review aimed to systematically collect, summarize, and assess current evidence on the relationship between dietary patterns and inflammatory biomarkers.

Data sources: The CINAHL, Cochrane Library, PubMed, Scopus, and Web of Science databases were searched from 1990 through March 19, 2025.

Data extraction: Systematic reviews and meta-analyses of intervention trials and observational studies that assessed the effects or associations of dietary patterns on chronic inflammatory markers were selected. Data extraction, methodological quality assessment, and evaluation of the strength of evidence were independently conducted by 2 authors.

Data analysis: Thirty reviews representing 225 eligible primary studies were included. Fifteen dietary patterns were assessed against a range of inflammatory marker outcomes, reported in 60 unique meta-analyses and 61 narrative syntheses. The findings indicate significant effects and overall beneficial association between the Mediterranean diet and the levels of inflammatory markers C-reactive protein (CRP), interleukin-6, and adiponectin, with the certainty of evidence (CoE) ranging from high to low. Additionally, a significant inverse association was identified between a vegetarian diet and CRP levels, with low to very low CoE. The findings for other dietary patterns assessed were inconclusive or limited due to the paucity of studies.

Conclusion: The Mediterranean and vegetarian dietary patterns may ameliorate low-grade inflammation in adult populations with at least one chronic condition. Further studies are needed to evaluate the potential inflammation-modulating effects of other dietary patterns, considering the significant heterogeneity of comparator diets.

Systematic review registration: PROSPERO no. CRD42023472469.