Oxidative stress induced by some preservatives and the protective effects of dietary bioactive compounds

Food preservatives such as nitrites, nitrates, sodium benzoate, and synthetic phenolic antioxidants are widely used to enhance the safety, stability, and sensory properties of foods. Despite these benefits, increasing evidence indicates that chronic or high-dose exposure to preservatives may induce oxidative stress, which plays a central role in the pathogenesis of cancer, metabolic disorders, and reproductive dysfunction. This review summarizes findings from animal, in vitro, and human studies on the relationship between preservatives and oxidative stress, with a focus on nitrites in processed meats and sodium benzoate. Experimental data consistently demonstrate increased lipid peroxidation, suppression of endogenous antioxidant enzymes, mitochondrial dysfunction, and apoptosis following high-dose preservative exposure, although these doses often exceed typical human dietary intake. Epidemiological studies support the association between nitrite-derived N-nitroso compounds and colorectal carcinogenesis, aligning with the International Agency for Research on Cancer (IARC) classification of processed meats as Group 1 carcinogens. In contrast, dietary bioactive compounds such as garlic oil, honey, Nigella sativa, curcumin, berberine, omega -3 fatty acids, and polyphenols have shown protective effects by modulating oxidative pathways and restoring redox balance. However, most of these benefits are observed at pharmacological levels, raising concerns about their practical relevance in human diets. Unlike previous reviews that focus solely on the toxicity of preservatives, this study uniquely integrates the mechanistic evidence of preservative-induced oxidative stress with the mitigating potential of functional food -based dietary strategies. Overall, preservatives may act as pro-oxidants under certain conditions, while antioxidant-rich dietary patterns may offer protective potential. Further human-based studies at realistic exposure levels are essential to strengthen risk assessment and guide public health recommendations.