Consuming a plant-based diet may help lower levels of a key marker of inflammation in the body, according to analysis of clinical trials led by University of Warwick researchers.
The study, published in Nutrition, Metabolism and Cardiovascular Diseases , is the first systematic review and meta-analysis of randomised controlled trials to assess whether plant-based dietary patterns influence levels of C-reactive protein (CRP), a widely used marker of systemic inflammation.
Chronic low-grade inflammation (‘inflammageing’) is increasingly recognised as a driver of age-related diseases, contributing to conditions including cardiovascular disease, type 2 diabetes, and some cancers.
Of nearly 3,000 studies initially identified as measuring plant-based diets and C-reactive protein (CRP), only seven met the strict criteria for inclusion as randomised controlled trials. Analysis of these trials, involving 541 participants, found that plant-based dietary patterns (including vegan, vegetarian, and wholefood plant-based diets) were associated with significantly lower CRP levels when compared to omnivorous diets.
Lead author Luke Bell, a student at Warwick Medical School, said: “We found that consuming a plant-based diet instead of an omnivorous diet reduced CRP levels by 1.13 mg/L on average. CRP is one of the body’s main signals of inflammation, and lower levels generally indicate less background inflammation circulating in the body.
“CRP levels are also commonly used to assess cardiovascular risk, with levels below 1 mg/L considered low risk and above 3 mg/L high risk. Therefore, a CRP reduction of the magnitude found in our study could move individuals into lower risk categories.”
Plant-based diets are typically rich in fruits, vegetables, whole grains, legumes, nuts, and seeds, and tend to contain higher levels of fibre, antioxidants, and unsaturated fats than diets including more animal products. Researchers believe the anti-inflammatory effect may be partly explained by these nutrients, as well as lower intakes of saturated fat.
Warwick co-author and project supervisor Joshua Gibbs added: “Plant-based diets are already known to improve key cardiovascular risk factors such as blood pressure, LDL cholesterol, and body weight. Our findings suggest an additional pathway through which these diets may reduce chronic disease risk.
“When studies that included structured exercise programmes were excluded, the reduction remained, although slightly smaller. The largest reductions were seen in studies that combined plant-based diets with increased physical activity, suggesting lifestyle changes may have the greatest impact when adopted together, although more research is needed to confirm this.”
Previous observational research has linked these diets to lower levels of inflammation and reduced risk of chronic disease, but unlike earlier reviews that relied largely on observational evidence, this analysis focused exclusively on randomised controlled trials - considered the gold standard for establishing cause and effect.
Co-author Professor Francesco Cappuccio, Warwick Medical School concluded: “It is worth bearing in mind that of the nearly 3,000 studies identified for this study, only seven met the inclusion criteria for randomised controlled trials. Although the results suggest a plausible effect of plant-based food in reducing inflammation, given the paucity of large trials, we should encourage more robust evidence to support these early findings.”
ENDS
The paper – ‘The effect of plant-based dietary patterns on C-reactive protein: A systematic review and meta-analysis of randomised controlled trials’ is published in Nutrition, Metabolism and Cardiovascular Diseases. DOI: 10.1016/j.numecd.2026.104631
Notes to Editors
For more information please contact:
Matt Higgs, PhD | Media & Communications Officer (Warwick Press Office)
Email: Matt.Higgs@warwick.ac.uk | Phone: +44(0)7880 175403
About the University of Warwick
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he effect of plant-based dietary patterns on C-reactive protein: A systematic review and meta-analysis of randomised controlled trials
18-Feb-2026
The authors declare no conflict of interest.