Interplay between dietary antioxidants and oxidative/nitrosative stress in stage III periodontitis: a preliminary quasi-experimental study in a Mexican population

Introduction Stage III periodontitis is a severe inflammatory disease characterized by significant tissue destruction. While Non-Surgical Periodontal Therapy (NSPT) is the gold standard, evidence suggests it may only or partially address of systemic oxidative imbalance. This study aimed to investigate the interplay between habitual dietary antioxidants, NSPT, and oxidative/nitrosative status in Mexican patients, a population with unique dietary patterns that may fuel disease pathways. Methods A preliminary quasi-experimental study was conducted with 24 adults (11 with periodontitis; 13 healthy controls). Clinical examinations were performed by a calibrated periodontist. Habitual diet was assessed at baseline using a validated SFFQ. Salivary and plasma levels of Total Antioxidant Capacity (TAC), protein carbonyls (CARBO), lipid peroxidation (LPO), and nitrate/nitrite were measured. Results The periodontitis group exhibited significantly higher energy and lower polyunsaturated fatty acid (PUFA) intake ( p < 0.05). A pivotal finding was the metabolic hyper-reactivity in diseased patients (30 significant nutrient-biomarker correlations vs. 5 in controls). Following NSPT, clinical parameters and plasma TAC improved ( p < 0.05); however, salivary MDA+4-HDA remained at 0.94 μM/L—above the healthy threshold of 0.77 μM/L, consistent with a non-significant reduction in the Plaque/Calculus Index( p = 0.059). Conclusions Our findings suggest that NSPT alone is insufficient to fully restore physiological oxidative homeostasis. The persistence of altered oxidative markers, linked to residual biofilm and dietary imbalances, supports the integration of targeted nutritional strategies as a necessary adjunct to achieve complete biological recovery in Stage III periodontitis; further large-scale studies are warranted to validate these results.