Ellagic acid is a naturally occurring substance. Ellagic acid is present in many red fruits and berries, including raspberries, strawberries, blackberries, cranberries, pomegranate and some nuts including pecans and walnuts. The highest levels of ellagic acid are found in raspberries. In plants ellagic acid is present in the form of ellagitannin, which is ellagic acid bound to a sugar molecule. Medicinally, ellagic acid is used to prevent cancer and treat viral and bacterial infections.
Ellagic acid may bind to chemicals that cause cancer, and it may also prevent the growth of cancer cells. However, ellagic acid is poorly absorbed and is also eliminated quickly from the body. These characteristics may limit its usefulness as a medicine.