gluten /’glōōtn/ ►n. a substance present in cereal grains, esp. wheat, that is responsible for the elastic texture of dough [16th C.: via Fr. from L., lit. ‘glue.’]
More technically, gluten is a protein composed of a prolamin (high in the amino acid proline) and a glutelin. In wheat, these are gliadin and glutenin. In barley, the prolamin is hordein; in rye, secalin.
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| (a) gluten = (b) elastic glutenin + (c) viscous gliadin. (From H. Charley and C. Weaver. Foods: A Scientific Approach, 3rd ed., 187. 1998.) |
These specific peptides (sequences of amino acids that make up a protein) cause all the trouble for those with Celiac’s disease. According to Krause’s Food and Nutrition Therapy, these peptides resist gastrointestinal enzymes and are not completely digested. Thus they are free to set off an autoimmune inflammatory response in a susceptible person, leading to all sorts of ‘mals’: malabsortption, malnutrition, malignancy, not to mention villous atrophy.
I suspect a phrase in that last paragraph jumped out at some of you: “not completely digested.” You’ve been vaguely suspicious of gluten for a while now. Does it really skulk around in our GI tract, dodging digestion?
Apparently, yes. According to the UCSD Wm. K. Warren Medical Research Center for Celiac Disease, “Gluten is resistant to proteolytic [protein-cutting] digestion… This is because there is a relative lack of enzymes with prolyl endopeptidase activity in human small intestine [remember how gluten’s proline-rich?].” In fact, scientists are investigating bacterial endopeptidases that destroy the triggering amino acid sequence in gliadin with hopes of developing an oral supplement, similar to lactase pills.
Bottom line: Eat more vegetables, substituting them for grains when probable.
Definition from The Oxford College Dictionary, 2nd ed., 2007.
What is the impact of the fact that gluten is undigested?
ReplyDeleteHow did grains become an essential part of many diets if gluten has a detrimental effect on people?
Excellent questions, Mr. Miller. Short answers:
ReplyDelete* As far as I can tell, for those without Celiac's, the impact of undigested gluten is nil. Proponents of the theory that a "leaky gut" affects those with autism would disagree.
* Grain is generally a cheap, plentiful, and easily stored source of calories. When agriculture took off 10,000 years ago, grains, including those with gluten, became the "staff of life" for many.