Apart from gluten there are a large number of other proteins in wheat. I wanted to go in to the problems of wheat germ agglutinin (WGA) in slightly more detail than I did the last time I posted on the toxicity of wheat.
WGA is a lectin. The technical definition of a lectin is a protein which attaches itself to a carbohydrate moiety on the surface of a cell and "does something" to the cell. WGA is an insulin mimic. This paper from 1973 sums it up nicely.
"wheat germ agglutinin [is] as effective as insulin in enhancing the rate of glucose transport and in inhibiting epinephrine-stimulated lipolysis in isolated adipocytes."
"The possible implications of these findings to certain biological properties (mitogenicity) of these lectins and to the mechanism of action of other growth-promoting substances are considered."
Mitogenicity is the key word. WGA causes cells to divide. Interestingly so does insulin, in pretty much the same areas of the gut as WGA...
Let's look at gut structure more closely. The surface of the gut is highly folded. The bits which stick up (villi) provide the brush border. The brush border is the area which does the actual digesting and absorbing of food. The folds between the sticky up bits are called the crypts. Deep in here active cell division occurs. As the cells divide they migrate up from deep in the crypts towards the brush border. As they migrate they mature until, as they arrive at the tips, they become typical brush border digestive cells. They do some digesting for a while, then get sloughed off to be replaced by more up and coming cells from deep in the crypts. It's tough at the top for a cell in the gut lining.
WGA, as we've noted, has "mitogenicity". The cells deep in the crypts, minding their own business, suddenly get told, by WGA, to divide. Now. Never mind biological need, complex inter-cell signaling, nutritional needs, just divide NOW. And again. Once more. Keep going.
Let's say normal gut turn over requires the cells get replaced every three or four days. It's around that. Crypt cells will divide to meet this need. Drop on WGA and they will divide irrespective of the needs of the gut. This results in rapid proliferation and migration of cells up up to the tips of the villi.
The end result, when WGA is given given to normal rats (note, these rats do not have gluten allergy), is a trashing of the gut, resembling early coeliac disease. Note the short villi.
With rapidly turning over digestive cells and minimal time for them to mature, how good will the brush border be?
Not very good!
The brush border produces all of the really interesting enzymes needed for the last stage of digestion. Most people know about lactase but the brush border also makes the enzymes to break down peptides to amino acids, all sorts of disaccharides to monosaccharides and even breaks down ingested triglycerides. Some of these enzymes are inhibited by WGA before it damages the gut, others are enhanced. Weird.
As a classic example, many many people are lactose in tolerant. They get gut rot when they drink milk. They may well avoid all dairy for the rest of their lives. However, it's pretty obvious from this thread that eating wheat trashes the brush border, where lactase is produced. This happens in NORMAL animals (and people). So it's impossible to genuinely say a human is lactose intolerant while they are eating wheat.
Humans are mammals after all, lactase is produced on demand whenever lactose is present, why should we be lactose intolerant?
If we have sub clinical coeliac disease then the loss of lactase is very straight forward. And very reversible.
My argument is that no one is likely to be tolerant of WGA. The effects on the gut lining do not require allergy, they are intrinsic to the nature of the lectin WGA and the glycosylation of the gut lining cells. Undoubtedly allergy will make matters much worse (and may give you a positive blood test, thus providing an ad lib supply of gluten free junk foods from the NHS).
Anyone unable to correctly digest fat, a specific protein or certain carbohydrates should really be thinking about wheat.
It's a metabolic poison.
I'm sounding like Dr Davis.
BTW, if WGA and insulin are so driving to mitosis, why don't they promote intestinal cancers? They do. Both of them. Though I guess omega 6 fatty acid excess and vitamin D deficiency should get a look in as partners in crime...
EDIT: see comments for a apology re reference inaccuracy on this BTW add on.