IMPACT OF PLANT BASED DIETS ON INFLAMMATORY MARKERS IN ADULTS A SYSTEMATIC REVIEW

Abstract

Background: Chronic low-grade inflammation is a key driver in the development of cardiometabolic and other non-communicable diseases. Diet, particularly plant-based eating patterns, has emerged as a modifiable factor influencing systemic inflammation. Although individual studies have investigated the impact of plant-based diets on inflammatory biomarkers, findings remain inconsistent due to variations in study design, population, and dietary assessment methods. A comprehensive synthesis of current evidence is needed to clarify the relationship and guide clinical nutrition strategies.

Objective: This systematic review aims to evaluate the effects of plant-based dietary patterns on inflammatory biomarkers, specifically C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α), in adult populations.

Methods: A systematic review was conducted following PRISMA guidelines. Electronic databases including PubMed, Scopus, Web of Science, and the Cochrane Library were searched for studies published between 2018 and 2024. Eligible studies included randomized controlled trials and observational studies examining the association between plant-based diets and inflammatory markers in adults. Two independent reviewers screened and selected studies, extracted data, and assessed risk of bias using the Cochrane Risk of Bias Tool and Newcastle-Ottawa Scale. Due to heterogeneity, a qualitative synthesis was performed.

Results: Eight studies met the inclusion criteria, comprising four randomized controlled trials and four observational studies with a total sample size exceeding 1,800 participants. The majority of studies reported significant reductions in CRP, IL-6, and TNF-α levels among individuals adhering to plant-based diets compared to omnivorous or conventional diets (p < 0.05). Risk of bias was generally low to moderate, with consistent findings across study designs.

Conclusion: Plant-based diets are associated with favorable reductions in systemic inflammatory biomarkers in adults, supporting their potential as a non-pharmacological strategy for reducing inflammation. However, further large-scale, long-term randomized trials are necessary to establish causality and explore underlying mechanisms.