Comparison of Five Oxidative Stress Biomarkers in Vegans and Omnivores from Germany and Finland

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

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.

Effect of a plant-based diet on oxidative stress biomarkers in male footballers

Proper nutrition plays a vital role in modulating oxidative status. There is an increasing popularity of plant-based dietary patterns among athletes. Therefore, the present study aimed to determine the plant-based diet index (PDI) score among male footballers and their non-athlete controls, as well as its relationship with oxidative biomarkers by evaluating the urinary excretion of F2alpha-isoprostane (F2a-IP) and 8-hydroxy-2'-deoxyguanosine (8-OHdG). A group of footballers (n = 45) and a healthy non-athlete group (n = 45) were selected. The two groups were matched based on body mass index (BMI) and age. The mean (standard deviation (SD)) age of the subjects was 22.88 (2.41) years, and their BMI was 22.08 (1.35) kg/m2. Anthropometric indices were evaluated, and fasting morning urine samples were analyzed to measure oxidative biomarkers. The PDI, unhealthy plant-based diet index (uPDI), and healthy plant-based diet index (hPDI) were calculated using valid food frequency questionnaire data. Generalized estimating equation models were used for all analyses. Compared to the non-athlete group, the PDI score was significantly greater in the footballer group (β = 9.8; P < 0.001), while the differences between the two groups in uPDI and hPDI scores were not significant. Overall, footballers consumed more plant-based foods. By examining the relationship between dietary indices and oxidative biomarkers, only a negative association was observed between PDI score and F2a-IP level (β = -1.25; P = 0.03). Based on the results, footballers were more adherent to a plant-based diet than non-athletes. In addition, it seems that following plant-based diets (the higher PDI) may exert beneficial effects on lowering F2a-IP levels due to improving the body's antioxidant status.