When Is A Gluten Free Diet Needed?

There is so much nutriton advice everywhere, often without any facts behind the advice.  Some say only buy organic, no dyes, no seafood, too much mercury.  Some say avoid meat, and above all avoid gluten. 

All this advice has no evidence behind it.  It should be taken with a grain of salt.
As an example, avoiding red meat is good advice for lowering cholesterol, however most will find it challenging to adhere too.  Cholesterol lowering medications lower lipids better, than diet.  As most of us know, diets rarely work.  You need to make lifestyle changes for long term health. 
Gluten has become the fad for many.  Gluten is the protein found in wheat, rye and other grains.  It gives the chewy texture to bread. 

Auto immune diseases such as sarcoidosis, myositis, and juvenile arthritis may be triggered by ingestion of gluten.  There are also many who have gluten related intestinal conditions, on regular diets.  There are many more people diagnosed with gluten related problems then years ago.
Diagnosis of Celiac requires a history and physical exam.  They look at symtoms, weight loss, and any GI issues.  The genetic markers, HLA-DQ2 and HLA-DQA are fairly sensitive.  A negative for these markers rule out gluten related conditions. 
 
The gold standard for determing whether gluten free eating is necessary is a biopsy of the small intestine, obtained by an upper endoscopy.