Purple sweet potatoes do contain a lot of anthocyanins. In fact, most higher plants contain anthocyanins, which are the products of plant metabolism. In addition to purple potato, eggplant, blueberry, red (purple) grape, cabbage, purple corn and other blue-purple vegetables and fruits have high anthocyanin content. Under different acidity and metal ions, plants will absorb sunlight with different wavelengths, thus making plants appear red, blue or purple. Anthocyanin also shows its powerful antioxidant function in chemical experiments or cell experiments carried out in the laboratory. Many people have studied this and published many related scientific papers, and confirmed that the antioxidant damage of cells is related to the occurrence of many chronic diseases, such as cancer and aging. Generally speaking, anthocyanins have a strong inhibitory effect on cancer cells cultured in vitro; For experimental animals such as mice, anthocyanins also show some resistance to artificially induced tumors. However, there is still a lack of corresponding evidence as to whether anthocyanins have anti-tumor effect in human body. Italian scientists have conducted some "case-control" studies, comparing the dietary status of thousands of cancer patients with "normal people" who are in a similar situation but not sick, and found no "effective components" in blue-purple vegetables such as anthocyanins related to cancer. Some scholars have also suggested that anthocyanins may not play a role once they are eaten into the human body. At present, all kinds of opinions about the anti-cancer effect of anthocyanins actually come from the theory of "anti-oxidation", and there is no direct clinical experimental data. Cell experiments and animal experiments can give scientists some research directions, but they still can't provide effective evidence. In the United States, a company once advocated the "special efficacy" of a certain blue-purple fruit, which was severely warned and stopped by the US Food and Drug Administration. Of course, this is not to say that there is anything wrong with purple potatoes. Any vegetables and fruits, whether blue-purple, green or yellow, are beneficial to human health. But for modern urbanites, the reason why vegetables and fruits can't play their due role is mostly "insufficient consumption". Therefore, it is not important to choose what kind of vegetables to eat. It is important that we should increase the quantity of various vegetables and fruits in our diet. -Jiangxi New Oriental