You may eat oranges and other citrus fruits and drink their juice because of their vitamin C, but they also contain other important nutrients. For example, at least 170 phytochemicals have been identified so far in orange juice. Citrus fruits contain carotenoids and fiber, notably pectin, which helps lower cholesterol. They are also rich in polyphenols, which include a wide range of flavonoids and related compounds, many with beneficial effects and nearly all with tongue-twisting names. Earlier research had also suggested that flavonoids such as those in citrus can lower the risk of stroke.
Oxidation increases artery-damaging deposits and thus promotes atherosclerosis.
Citrus skin contains D-limonene and coumarins, which leach into the juice. Coumarins help reduce blood clotting and may also have anti-cancer capacity. Certain compounds that give citrus fruit their bitter taste are also believed to have antioxidant and anti-cancer effects. Besides beta carotene, pink and red grapefruit provide lycopene, another carotenoid, which may help prevent prostate cancer. Heat, including pasteurization, reduces vitamin content.