BACKGROUND/OBJECTIVES: This study aimed at evaluating the relationship of adiponectin concentration with total dietary antioxidant capacity in free-living, apparently healthy adults from the ATTICA study. SUBJECTS/METHODS: A random subsample from the ATTICA study, consisting of 310 men (40+/-11 years) and 222 women (38+/-12 years), was selected. Adiponectin, along with other inflammatory markers, was measured in fasting participants. Dietary habits were evaluated using a food frequency questionnaire and the dietary antioxidant capacity was based on published values of Italian foods measured by three different assays: ferric-reducing antioxidant power (FRAP), total radical-trapping antioxidant parameters (TRAP) and trolox-equivalent antioxidant capacity (TEAC). RESULTS: Positive associations were observed between dietary antioxidant capacity and adiponectin concentration, as assessed with FRAP (b+/-s.e.=0.012+/-0.005, P=0.018 per 1 mmol Fe (II)/day), TRAP (b+/-s.e.=0.030+/-0.013, P=0.017 per 1 mmol trolox equivalent/day) and TEAC (b+/-s.e.=0.025+/-0.012, P=0.042, per 1 mmol trolox equivalent/day) in multiadjusted analysis. Moreover, a negative relation of dietary antioxidant indices with inflammatory markers was revealed. CONCLUSIONS: Diets with high antioxidant capacity are related to increased adiponectin levels. An adiponectin-mediated route through which antioxidant-rich foods exert beneficial effects against inflammation and cardiovascular diseases can be thus hypothesized.