There's a lot of really neat discussion of food chains and local sourcing going on around here lately. Enough people have asked questions about gluten in the various food threads that I thought I'd put some of the information that I've been posting as comments, together in one diary.
The main questions seem to be:
What is gluten?
Where does it occur?
If I eat a lot of bread do I have to worry?
How do I avoid gluten?
What is gluten?
There's naturally occurring gluten, which occurs in grains. People with celiac disease are generally allergic to the gluten found in wheat, spelt, triticale, barley (that's why no beer), and rye, and possibly oat gluten as well.
The desirable properties of gluten are that it forms stretchy chewiness in your food. That's why wheat bread has such a unique texture. Making the gluten come out is why you knead wheat dough.
Where does gluten occur?
Naturally processed totally pure organic stone ground wheat flour will still have this kind of gluten, but not as the melamine-contaminated additive.
Then there's additive gluten. This is made by essentially washing away the starch from flour, leaving the higher-protein gluten behind. Of course on a grand scale mechanical processing is involved, but you can prepare gluten in your kitchen.
Additive (extracted and reprocessed) gluten can be found anywhere chewiness is wanted, or thickening:
-- fake meat products
-- specialty high-gluten bread flours
-- prepared gravies, sauces, and soups
-- any processed baked product that's assembled from a long list of chemical ingredients -- packaged breads, cookies, donuts, crackers, etc.
Do I have to worry if I eat a lot of bread?
You want to not worry about the natural gluten that occurs in bread.
However, some high-gluten bread flours and possibly the gluten you can buy in the supermarket (in my area it's Hodgson's Mill brand) probably contain gluten that has been made in an industrial process. Whether that's a safe process depends on the supplier. Melamine would only get in there if the supplier was doing something evil to artificially up their nitrogen content, it's not an ordinary outcome of the process.
If you want to be safe from the additive, either buy ingredients and bake your own breads, cookies and muffins, or buy from a local bakery that prepares food for local, immediate consumption, and that's willing to talk to you about the ingredients they use.
How do I avoid gluten?
- Read the labels, especially of highly processed products with long and arcane ingredient lists. People with celiac have to avoid even traces, and those can be in something as innocuous as "hydrolized vegetable protein" or the outsides of vitamin capsules.
- Buy the ingredients, not the finished product. For an earlier take on avoiding unnecessary additives, see this diary from last night.
The USDA has recently come out with a "food pyramid" for people of Hispanic origin. It relies heavily on traditional dietary patterns of those cultures to result in a healthy diet. They are selling it with the slogan "the old ways are best". The old ways are best. Make your own food, with ingredients you recognize.
Also, as someone asked in the other thread:
Not to be rude, but are you a nurse or md?
Answer: no. I have celiac myself, and I'm a Ph.D. biophysicist who also spent much of my 20s organizing and running natural food and housing cooperatives. I've got a lot of arcane food-sourcing and cooking knowledge and a fair bit of science to back it up.