Washing fruit before you eat is medically advised in order to reduce the risk of ingesting anything that may prove harmful to your health. Thoroughly washing the fruit can help reduce the chances of ingesting the following:

Pesticides and Other Chemicals

Most fruit are grown on non-organic farms. This means that pesticides and other chemicals were sprayed on the fruit in order to decrease the number of insects infecting the fruit. Even organic fruit (unless it's labeled 100% organic) may have a small amount of pesticides and other chemicals. While trace amounts of these chemicals have not been proven to lead to adverse health effects, it's better to be cautious and remove as much of the chemicals as possible.

Insects and Insect Waste

Washing fruit will also help you remove any insects and insect waste that may linger on your fruit. Because the fruit is likely grown outdoors and then makes a long journey during transit, it has plenty of opportunities to attract insects.

Dirt and Grime

On the farm, the fruit may have encountered dirt, which could have had chemical fertilizers. As the fruit is picked, packed and transported, it can accumulate dirt and other grime that may be unhealthy for you to consume. Washing fruit helps remove the dirt and grime.

Bacteria

Fruit can accumulate bacteria from the farm or from any of the handlers who pick, deliver and display the fruit at your local store. Just as you would wash your hands before eating in order to reduce bacteria on your hands, washing fruit can help reduce the bacteria that may be present on your fruit.