An animal food supplement for use in improving cognitive function in animals comprises one or more natural plant-based antioxidants, one or more sources of vitamin C and one or more sources of vitamin E. The plant-based antioxidants may comprise bioflavonoids such as polyphenolic flavonoids and may be present as a fruit, plant, fruit extract or plant extract, such as beetroot, spinach, pomegranate, blackcurrants or blackberries. The vitamin C source may comprise ascorbic acid and/or rosehip while the vitamin E source may comprise mixed tocopherols and/or tocotrienols. The supplement may also contain rosemaric acid and sacrificial antioxidants including gallic acid, a source of carotenoids and one or more of carrot, tomato or oregano. A method feeding animals, such as dogs, horses, rabbits, livestock or poultry, the supplement to improving learning ability, memory or cognitive function is disclosed. This may involve providing an animal with 0.2g to 20g or from 1g to 5g of the supplement per kilogram of body weight per day.
