Fruit can be used to help your body detoxify. The best way of doing this is not to eat anything but fruit untill noon. Until that time your body is still busy detoxifying from the night before. Freshly squeezed juices are the best ofcourse. The strongest detoxifying effect is caused by the acid fruits, especially by lemons.
Citrus fruit is all acid fruit.
Now you know why people always drink fresh squeezed oranges in the morning. Squeeze 3 oranges, two mandarins and half a red grapefruit for breakfast. It also gives you a lot of energy. Be a little-bit careful with the acid fruits when you are ill. Your body is already busy detoxifying and stimulating, so this may cause an overreaction of your body to clean itself even more and can make you even more sick for that moment.