The present invention relates to a peptide that is derived from a milk protein and has an antioxidative effect, an antioxidant that includes the peptide as an active ingredient, and an antioxidative food, drink, or feed that includes the peptide. The present invention also relates to a peptide that is derived from a milk protein and has an adiponectin production promotion effect, an adiponectin production promoter that includes the peptide as an active ingredient, and an adiponectin production promotion food, drink, or feed that includes the peptide. The present invention further relates to a blood adiponectin level increase promotion and/or decrease inhibition agent that includes a component contained in cheese as an active ingredient, and a blood adiponectin level increase promotion and/or decrease inhibition food or drink that includes a component contained in cheese. The present invention to the peptide that consists of an amino acid sequence shown by His-Pro-Ile-Lys-His-Gln-Gly-Leu-Pro-Gln (1), His-Pro-Ile-Lys (2) or His-Gln-Gly-Leu-Pro-Gln (3), and has an antioxidative effect.