Pomegranates are high in polyphenols. The most abundant polyphenols in pomegranate are hydrolysable tannins, particularly punicalagins, which have been shown in many peer-reviewed research publications to be the superior antioxidant responsible for the free-radical scavenging ability of pomegranate juice. In several human clinical trials, the juice of the pomegranate has been found effective in reducing several heart risk factors, including ldl oxidation, macrophage oxidative status, and foam cell formation, all of which are steps in atherosclerosis and heart disease. Tannins have been identified as the primary components responsible for the reduction of oxidative states which lead to these risk factors. Pomegranate juice has recently been tested for its efficacy against prostate cancer.