Researchers at the University of Warwick pooled seven randomized controlled trials and found that plant-based dietary patterns reduced C-reactive protein (CRP) by an average of 1.13 mg/L compared with omnivorous diets. The analysis of 541 participants appeared in Nutrition, Metabolism and Cardiovascular Diseases in 2026.
CRP is a blood marker of chronic low-grade inflammation, and higher levels have been linked to heart disease, type 2 diabetes, and cognitive decline.
The American Heart Association places CRP above 3 mg/L in the high-risk band for cardiovascular disease. The average band runs from 1 to 3 mg/L, so a shift of about 1 mg/L is enough to move some people into a lower category.
Seven everyday foods keep showing up in dietary research on inflammation: fatty fish, extra-virgin olive oil, berries, leafy greens, whole grains, walnuts, and tomatoes. Each has its own evidence base, and the specific inflammatory marker it acts on is not always CRP.
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Fatty fish
Salmon, sardines, and mackerel supply the long-chain omega-3 fats EPA and DHA. An umbrella meta-analysis of trials reported that omega-3 supplementation lowered CRP, TNF-alpha, and interleukin-6, with the combination of EPA and DHA producing the broadest effect.
Extra-virgin olive oil
A 2025 meta-analysis in Nutrition and Metabolism found that a Mediterranean pattern enriched with olive oil reduced CRP with a standardized mean difference of -0.96 and lowered interleukin-6 as well. The active fraction is thought to be polyphenols such as oleocanthal, which are concentrated in extra-virgin oil.
Berries
Blueberries, strawberries, and other anthocyanin-rich berries appear in a meta-analysis of 44 randomized trials as significantly lowering CRP, with the largest anti-inflammatory effect seen at higher intakes. Anthocyanins are the pigments that give berries their color.
Leafy greens
Spinach, kale, and other dark greens supply carotenoids and folate. Direct trial evidence for CRP is thinner than for berries or olive oil, but leafy greens are a cornerstone of the Mediterranean pattern, which an umbrella review in the British Journal of Nutrition tied to a CRP reduction of 0.71 mg/L in randomized trials.
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Whole grains
A meta-analysis of nine trials covering 838 participants reported significant reductions in both CRP and interleukin-6 after whole-grain interventions. Later analyses have been more mixed, with the effect strongest in people who started with elevated CRP.
Walnuts
A meta-analysis of 17 walnut trials in middle-aged and older adults did not find a significant change in CRP, but it did report lower interleukin-6, TNF-alpha, and IL-1beta. Walnuts also lowered LDL cholesterol, another driver of cardiovascular risk.
Tomatoes
A meta-analysis of clinical trials found that tomato intake did not significantly change CRP but was linked to a reduction in TNF-alpha and, in some analyses, interleukin-6. Tomatoes are the main dietary source of lycopene, a carotenoid studied for its antioxidant activity.
Lead author Luke Bell of Warwick Medical School said in a statement that "CRP is one of the body's main signals of inflammation, and lower levels generally indicate less background inflammation circulating in the body."
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Coauthor Professor Francesco Cappuccio cautioned that "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."
For anyone who has seen an elevated CRP result on a routine blood test, no single food will move the number on its own. Repeated readings and any decisions about treatment should be discussed with a doctor.
A single high value can also reflect a recent infection or injury rather than chronic inflammation, especially when it climbs above 10 mg/L.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.