[PROBLEMS] To provide: a composition having an excellent antioxidative activity； a food or beverage utilizing the composition； and a method for producing the composition. [MEANS FOR SOLVING PROBLEMS] Disclosed are: a composition comprising at least one member selected from a processed product of a plant belonging to Cistache Tsubulosa (so-called "Kanka") and a processed product of a plant belonging to Withania sominifera (so-called "Ashwagandha") and a processed product of a plant belonging to Panax quinquefolium, wherein the composition may further comprise a processed product of a plant belonging to Panax ginseng and/or a processed product of a plant belonging to Lepidium meyanii； a food or beverage produced by using the composition； a method for producing the composition； and a method for increasing the antioxidative activity of a plant belonging to Cistache Tsubulosa and/or a plant belonging to Withania sominifera.
