Basically it's the consumer-sheep principle: whatever is in fashion will be sold, regardless of the reality of the product. So if "gluten-free" is popular, then you can slap a sticker on a chemical list & people will buy it. For example, Domino's Pizza has a gluten-free crust option now; one of the ingredients is Avicel, which is a brand name for cellulose. They are literally
selling you sawdust in your food now:
http://en.wikipedia.org/wiki/Microcrystalline_cellulose
The best part is that selling wood as food is
completely legal. It falls under GRAS (generally recognized as safe) since it's been around for 30+ years. They use it in stuff like vitamin pills & low-fat foods because it makes you feel full, but doesn't have any negative (or positive) effect on your body:
http://www.accessdata.fda.gov/scripts/fcn/fcnDetailNavigation.cfm?rpt=scogslisting&id=160
Must be safe, right?