A dietary supplement consisting of a mixture of strawberries, blackberries, black raspberries and blueberries with potential antineoplastic activity. Although the exact mechanism of action through which berries may exert their anti-tumor effect has yet to be elucidated, in vivo studies suggest that the ingestion of a mixture of berries seems to result in a reduction in tumor growth and tumor development. As berries are rich in phytonutrients, such as anthocyanins, flavonols, ellagitannins, galltannins, proanthocyanidins, and phenolic acids, the antineoplastic effects of strawberry-blackberry-black raspberry-blueberry berry mixture on cancer cells may be attributable to phytonutrient antioxidant and apoptotic activities. In addition, phytoestrogens in berries may be protective against estrogen-sensitive tumors.