Dietary Patterns, Oxidative Stress, and Early Inflammation: A Systematic Review and Meta-Analysis Comparing Mediterranean, Vegan, and Vegetarian Diets

Nutrients. 2025 Jan 31;17(3):548. doi: 10.3390/nu17030548.

Abstract

Background: Dietary habits influenced by lifestyle and cultural factors play a critical role in health by modulating oxidative stress and inflammation. While diets offer significant benefits, they may also pose risks, such as nutrient deficiencies, emphasizing the need for a balanced approach. Exploring Mediterranean and plant-based diet effects on oxidative stress and inflammation biomarkers may help improve health outcomes and disease prevention strategies.

Methods: This study analyzed 65 studies following PRISMA guidelines to evaluate the effects of Mediterranean and plant-based diets on biomarkers of oxidative stress and inflammation in healthy individuals.

Results: The Mediterranean diet was weakly associated with reductions in oxidative stress markers, including MDA (ROM: 0.80; 95% CI: 0.57-1.13; p = 0.2092) and 8OHdG (ROM: 0.81; 95% CI: 0.59-1.11; p = 0.1847), as well as inflammation markers such as CRP (ROM: 0.72; 95% CI: 0.42-1.23; p = 0.1545) and IL-6 (ROM: 1.23; 95% CI: 0.97-1.55; p = 0.08). The vegetarian diet significantly reduced CRP (ROM: 0.82; 95% CI: 0.69-0.98; p = 0.0297), while the vegan diet showed a borderline reduction (ROM: 0.81; 95% CI: 0.56-1.17; p = 0.2544), suggesting lower systemic inflammation compared to omnivorous diets.

Conclusions: Although all three diets demonstrate potential in reducing oxidative stress and inflammation, the antioxidant effects-especially for the Mediterranean diet-are lower than anticipated, indicating alternative mechanisms. Further research is essential to confirm these findings and clarify the underlying mechanisms to enhance preventive health strategies.

Keywords: Mediterranean diet; healthy subject; inflammation; oxidative stress; plant-based diet; vegan diet; vegetarian diet.

Publication types

  • Systematic Review
  • Meta-Analysis

MeSH terms

  • Adult
  • Biomarkers / blood
  • Diet, Mediterranean*
  • Diet, Vegan*
  • Diet, Vegetarian*
  • Feeding Behavior*
  • Female
  • Humans
  • Inflammation* / prevention & control
  • Male
  • Middle Aged
  • Oxidative Stress*

Substances

  • Biomarkers