Disclosed are: an antioxidant agent which comprises, as an active ingredient, a peptide having an antioxidative effect and an adiponectin production-promoting effect and comprising the amino acid sequence represented by the formula: His-Pro-Ile-Lys-His-Gln-Gly-Leu-Pro-Gln, His-Pro-Ile-Lys or His-Gln-Gly-Leu-Pro-Gln； a beverage/food containing the antioxidant agent； an agent for promoting the production of adiponectin； a beverage/food containing the agent； an agent for promoting the increase in and/or preventing the decrease in the blood adiponectin level, which contains a component contained in a cheese as an active ingredient； and a beverage/food for promoting the increase in and/or preventing the decrease in the blood adiponectin level, which contains an active ingredient of a cheese.
