A pilot study of autistic children studied the effects of removing gluten from their diet (Autism, 1999; 3: 45-69). In the study, once gluten containing foods were eliminated, a majority of children showed noticeable improvements, particularly in language development, ability to concentrate, and sleep patterns. The more severe the autism, the more pronounced the improvement.
Our bodies were never meant to digest this substance, which also has a sticky, binding effect on the intestines. Whether or not a person has Celiac disease, many many people have gluten sensitivity, which can lead to Celiac Disease and is capable of causing problems in and of itself. When you eat something you have an immune sensitivity to, your immune function is directed away from things like incoming viruses, bacteria, and even cancer growth to fight off the proteins to which one is allergic/sensitive. It is when the immune system isn't functioning properly that yeast overgrowth can occur, compounding health problems. Celiac disease is the end stage of gluten sensitivity, so avoiding gluten can lift a great burden off the body and prevent problems down the road.
If you're worried about getting enough protein, calcium, grains, etc. in your diet, there are many ways to ensure that you do this. Incorporating gluten-free grains like quinoa (which contains more complete protein than a serving of any meat), corn, rice, and other such whole grains into the diet can ensure that you're getting enough whole grains in the diet, which is very important for good nutrition. There are flours made from rice, corn, and other gluten-free sources, as well.
While I mostly agree with you Tracii, I disagree that grains are a "necessary" part of the diet. People who go gluten free should not "worry about getting enough grains". We evolved for tens of thousands of years with few to no grains in our diet. That is WHY so many people are gluten intolerant.
Most people would be better served by not trying to "replace" glutinous grains with other grains. And MANY people who are gluten intolerant are also allergic to corn and sometimes rice as well. So I find that many people who are gluten sensitive and go gluten free feel WORSE because they begin eating larger amounts of OTHER foods that they are allergic to.
Grain free is actually the better way to go until you KNOW whether you are allergic or sensitive to those other grains (and soy) as well.
I remember taking Mickie off Casein and Gluten when he was five. It can be safely done, just as long as everytime you remove a food item from the diet, you provide him with supplements to replace what is missing in the diet.