In particular elderberries are rich in the phytochemicals known as flavonoids. The class of flavonoid that elderberry is loaded with is anthocyanins. The elderberry is the most concentrated source of anthocyanins. These anthocyanins act as a potent immune system booster protecting cells and keeping the body from harm. According to research by Dr. Rechkemmer, president of Germanys Federal Research Institute for Nutrition and Food, the purpleblack pigment of the elderberry containing the anthocyanins promote the production of cytokines.