I tracked down the full-text of that beef allergy study I wrote about previously. The results are very interesting.
The authors tested subjects in Argentina with asthma, skin problems, or stomach problems. It turned out that 57.6% of them showed an a hypersensitivity to beef. 57.6%! This was much higher than tests for either cow's milk or wheat flour.
Subjects then went on a cow's meat exclusion diet for 6-12 months. Skin problems and gastrointestinal problems were drastically reduced or eliminated. Some patients with asthma were able to go off steroids.
After the exclusion period, subjects with skin and stomach problems were able to tolerate beef again. Subjects with asthma still were not able to. The authors believe that intestinal permeability was the factor that made beef allergenic.
So what's going on here? You would think beef should be normally tolerated. First, results are different country to country. For example, in Chinese subjects with eczema, there is a low prevalence of beef allergy. Yet in this same study it says:
"Specific IgE levels for beef correlated with all the other food-specific IgE levels."
Here's my educated guess: once intestinal permeability is created via other allergenic foods (wheat, milk, soy, etc.), then beef proteins become allergenic. Interestingly, in the first study when beef was introduced during the exclusion period, patients immediately developed symptoms. So maybe intestinal permeability has to be healed by excluding both beef and other allergenic foods before it can be properly tolerated.
So should people be avoiding beef? It may be something that people with asthma, allergies, eczema, or autoimmune diseases may want to consider. I realize this is the equivalent of blasphemy in the Paleo world, but I'm just reporting what's in the study. The study looked legit to me, so hopefully there will be follow up work done.