This is a very important question. There are two main reasons why organic foods are better.
First, organic foods (vegetable and fruits) are grown without unnatural substances. More specifically, organic foods do not use pesticides, insecticides, and herbicides. This is important, because there are health ramifications when humans ingest these substances. We need to keep in mind that washing does not get everything off.
Second, when it comes to animals, there are no growth hormones that are injected into animals. Also they are given room to roam and eat what they normally eat. The point is that there is nothing artificial given to them. So, when human eat them, it is all natural.
All of this makes for healthy eating and healthy people.