Antioxidant damage of cells is related to the occurrence of many chronic diseases, such as cancer, aging and cardiovascular diseases. Because fruits and vegetables have a certain effect on reducing the risk of cancer, people naturally think that anthocyanin is not an effective component of cancer. Many people have studied this and published a large number of scientific papers. 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, whether it is effective for human body is lack of corresponding evidence. Italy has conducted some "case-control" studies, comparing the dietary status of thousands of cancer patients with similar but unaffected "control groups", and found no "effective components" in blue-purple vegetables such as anthocyanins related to cancer. The gradual accumulation of cell damage plays a very important role in the origin of aging. However, the source of many cell injuries-some can really cause aging, and some have nothing to do with aging-is still an unsolved mystery.

As a specific marker of oxidative damage in vivo, protein oxidation products mediated by free radicals are one of the hot spots in free radical biology research in recent years. Protein is the main target of free radicals and other oxidants in the environment inside and outside cells. It is estimated that the free radicals scavenged by protein account for 50% ~ 75% of the total active free radicals in intracellular macromolecules. Due to the long half-life of some protein, it is easy to cause the accumulation of oxidative damage, so the formation of oxidative damage in protein may be a highly sensitive indicator of oxidative damage in mammals. Oxidative damage of protein caused by reactive oxygen species is related to aging, tumor, diabetes and many neurodegenerative diseases.