The Impact of Organic Diet on Antioxidant Capacity and Biomarkers of Inflammation and Oxidative Stress

Abstract

Introduction: Few studies have reported on the association between a systematic consumption of organic diet and human health effects. Pesticides, commonly used in conventional, but not in organic agriculture, could lead to generation of reactive oxygen species, indicative of oxidative stress and inflammatory responses. We aimed to evaluate the literature on the association between organic diet and biomarkers of inflammation, oxidative stress and antioxidant capacity. Methods: Using PubMed, we searched for peer-reviewed articles that examined the influence of organic diet interventions in altering key biomarkers of oxidative stress, inflammation and antioxidant capacity in human studies; in-vitro and animal studies were excluded. Results: Only 9 relevant human studies were identified. Some of the biomarkers assessed in these articles were vitamins, cytokines, malondialdehyde and C-reactive protein. For most biomarkers, no statistically (p>0.05) significant differences were observed between conventional and organic diet interventions. In three crossover studies, organic diet resulted in significant (p<0.05) changes for markers of antioxidant capacity (vitamin B12, carotenoids, flavonols, total plasma antioxidant capacity), inflammatory biomarkers (tumor necrosis factor-alpha, interleukin-6 and -1) and for biomarkers of oxidative stress (protein oxidation). Conclusions: The small number of existing studies and their heterogeneity did not provide us with solid evidence on the association of organic diet with biomarkers of oxidative stress and inflammation. Randomized controlled human trials with sufficient power and long enough windows of monitoring exposures and biomarkers of effect should be implemented.