"There also appears to be an increased incidence of celiac disease, with one study which looked for antibodies from 1950s American blood samples finding that celiac disease is about four times as common as it was"

http://en.wikipedia.org/wiki/Gluten-free_diet#Popularity_and...

"One study examined the effect of ω-5 gliadin, the primary cause of wheat dependent exercise/aspirin induced anaphylaxis, and found increased permeability of intestinal cells caused by this gliadin and another wheat albumin."

http://en.wikipedia.org/wiki/Gluten_sensitivity#Gluten_toxic...

"Another line of research shows gliadin binds a chemoattractant receptor and causes increases of a factor that destroys tight junctions. These junctions prevent leakage around the cells that line the small intestine, resulting in the leaking of food proteins into the body."

http://en.wikipedia.org/wiki/Gluten_sensitivity#Gluten_toxic...

Except that all kinds of auto immune diseases and alergies are rising across the board - so may be something else going on (An article in NYTimes recently suggested that we live in so (relatively) sterile environment that out immune system cannot calibrate itself and is going berserk with the smallest irritant)

The first study is correlative, not causative.

The second and third studies are a bit too specific. Can you break this down into a list of effects on every day people?

I think this quote sums it up best: "Gluten intolerance is one of the most popular self-diagnoses because of its over-expanded list of potential symptoms. The gluten scare is mostly an overblown hippy-fueled movement."

It seems like the jury is still out on how many people suffer from gluten sensitivity, or the extent of the negative effect of gliadin.

> A 2011 panel of celiac experts concluded that there is a condition related to gluten other than celiac disease and named it "non-celiac gluten sensitivity".[51] however, for those without celiac disease or gluten sensitivity, the diet is unnecessary.

Here's one:

Gluten causes gastrointestinal symptoms in subjects without celiac disease: a double-blind randomized placebo-controlled trial.

http://www.ncbi.nlm.nih.gov/pubmed/21224837

On a visual analog scale, patients were significantly worse with gluten within 1 week for overall symptoms (P=0.047), pain (P=0.016), bloating (P=0.031), satisfaction with stool consistency (P=0.024), and tiredness (P=0.001).