A drug for preventing and/or treating diseases. The diseases are Alzheimer's disease, diabetes, or aging. The drug comprises a first active ingredient. The first active ingredient comprises one of carrimycin, isovalerylspiramycin I, isovalerylspiramycin II, and isovalerylspiramycin III, or a combination of two or three of isovalerylspiramycin I, isovalerylspiramycin II, and isovalerylspiramycin III.