Anthocyanins, a type of flavonoid found in fruits and vegetables, have been studied for their potential cancer-preventive properties. This review summarizes the latest findings on their anti-carcinogenic effects in cell culture models and animal tumor systems, along with their molecular mechanisms. The daily intake of anthocyanins in the U.S. is estimated to be about 200 mg, which is nine times higher than other dietary flavonoids. Epidemiological studies suggest that anthocyanins may reduce the risk of cancer, cardiovascular disease, diabetes, and arthritis due to their antioxidant and anti-inflammatory activities. In vitro studies show that anthocyanins exhibit antioxidant effects by scavenging reactive oxygen species (ROS), activating phase II detoxifying enzymes, and reducing cell proliferation. They also induce apoptosis through intrinsic and extrinsic pathways, inhibit angiogenesis, and reduce inflammation by modulating inflammatory proteins like NF-κB and COX-2. In vivo studies in animals demonstrate that anthocyanins can inhibit the development of esophageal, colon, and skin cancers. However, human epidemiological studies have not consistently shown anti-cancer effects, possibly due to differences in bioavailability and metabolism between animals and humans. Anthocyanins are absorbed as intact glycosides but have poor bioavailability. Their metabolism in humans and animals is limited, and they are excreted in urine within 4–8 hours. Despite their potential in laboratory models, the concentrations required for anti-cancer effects in vitro are much higher than those found in human plasma. Future research should focus on enhancing anthocyanin absorption and metabolism to improve their chemopreventive efficacy in humans, particularly in tissues other than the gastrointestinal tract and skin. The role of gut bacteria in anthocyanin metabolism and the need for further studies on their mechanisms of action are also highlighted.Anthocyanins, a type of flavonoid found in fruits and vegetables, have been studied for their potential cancer-preventive properties. This review summarizes the latest findings on their anti-carcinogenic effects in cell culture models and animal tumor systems, along with their molecular mechanisms. The daily intake of anthocyanins in the U.S. is estimated to be about 200 mg, which is nine times higher than other dietary flavonoids. Epidemiological studies suggest that anthocyanins may reduce the risk of cancer, cardiovascular disease, diabetes, and arthritis due to their antioxidant and anti-inflammatory activities. In vitro studies show that anthocyanins exhibit antioxidant effects by scavenging reactive oxygen species (ROS), activating phase II detoxifying enzymes, and reducing cell proliferation. They also induce apoptosis through intrinsic and extrinsic pathways, inhibit angiogenesis, and reduce inflammation by modulating inflammatory proteins like NF-κB and COX-2. In vivo studies in animals demonstrate that anthocyanins can inhibit the development of esophageal, colon, and skin cancers. However, human epidemiological studies have not consistently shown anti-cancer effects, possibly due to differences in bioavailability and metabolism between animals and humans. Anthocyanins are absorbed as intact glycosides but have poor bioavailability. Their metabolism in humans and animals is limited, and they are excreted in urine within 4–8 hours. Despite their potential in laboratory models, the concentrations required for anti-cancer effects in vitro are much higher than those found in human plasma. Future research should focus on enhancing anthocyanin absorption and metabolism to improve their chemopreventive efficacy in humans, particularly in tissues other than the gastrointestinal tract and skin. The role of gut bacteria in anthocyanin metabolism and the need for further studies on their mechanisms of action are also highlighted.