A major challenge for the food industry is to satisfy the consumer demand for health benefits as well as taste. In this study, we investigated the antioxidant activities of extracts from four anthocyanin-rich jams, as well as their low-sugar versions, which used white grape juice concentrate as a white refined sugar substitute. It was determined that blueberry + Korean black raspberry jam dramatically scavenged 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid), peroxyl radicals, and reduced ferric ions in the tested jams and contained high amounts of phenols, flavonoids, and anthocyanins. In addition, the antioxidant capacity and content of phenolics, flavonoids, and anthocyanins were retained during the processing of berry jams. Berry jams and their low-sugar jams exhibited inhibitory effects on reactive oxygen species production in HepG2 cells and lipid peroxidation in the liver and brain homogenates. In conclusion, blueberry + Korean black raspberry and raspberry + strawberry jams have strong antioxidant capacities, which are retained in jams containing sugar substitutes. These results suggest that anthocyanin-rich berry jams with natural sugar replacements could be developed as high functional foods and also decrease the risk for metabolic diseases.