The effect of plant-based dietary patterns on C-reactive protein: A systematic review and meta-analysis of randomised...

Chronic low-grade inflammation, termed "inflammageing", accelerates many age-related diseases. C-reactive protein (CRP) is a well-validated biomarker of inflammation and is an independent predictor of cardiovascular events. Plant-based dietary patterns (PBDPs) supply greater intakes of antioxidants and unsaturated fats than omnivorous diets and have been linked to lower circulating CRP concentrations in observational studies, but a causal relationship remains unclear. The main objective of this meta-analysis was to determine the effects of PBDPs on CRP concentration when compared to omnivorous dietary patterns in controlled clinical trials.

MEDLINE, Embase and Web of Science were searched to identify trials investigating the effect of PBDPs on CRP concentration. Standardised mean differences in CRP and 95% confidence intervals were pooled using a random-effects model. Risk of bias, heterogeneity and sensitivity were assessed. Of the 2962 studies identified, only 7 clinical trials met the inclusion criteria, generating eight data sets (541 participants of median age 55 years). In the analysis of all 7 trials, the consumption of PBDPs was associated with significantly lower CRP (-1.13 mg/L (95% CI, -1.52 to -0.75). Subgroup analysis excluding studies with exercise prescriptions showed PBDPs were associated with significantly lower CRP (-0.94 mg/L (95% CI -1.43 to -0.46). Heterogeneity was high and the certainty of the results was low.

Consumption of PBDPs may lower CRP concentration but further evidence gathering is required to validate this finding.