Saturday, December 14, 2013

Autoimmunity and Wheat

Reposted from Wheat Belly

by Dr. William Davis

Autoimmunity occurs when your own immune system is no longer able to distinguish friend from foe. It means that antibodies, lymphocytes, killer T cells, macrophages and inflammation-mediating proteins can’t tell the difference between, say, the protein of a fungal wall from proteins in your liver or joints. It’s as weird as a mother not recognizing her children, sometimes as tragic as friendly fire.
Depending on which tissues in which organs are attacked, the misdirected immune attack of autoimmunity can express itself as autoimmune hepatitis (liver tissue), primary biliary cirrhosis (bile ducts), type 1 diabetes (pancreatic beta cells), uveitis (iris of the eye), skin (psoriasis), platelets (autoimmune thrombocytopenic purpura), muscles (polymyositis), thyroid (Hashimoto’s thyroiditis, Grave’s disease), or just about any other organ or tissue.

Wheat consumption has now been confidently identified as both the initiating process in autoimmunity, as well as a perpetuating factor. Autoimmunity is just one way that tells us that this “food” was never appropriate for human consumption in the first place. First consumed in desperation 10,000 years ago, after not consuming grains for the preceding 2.5 million years, then altered by the efforts of geneticists and agribusiness, increased wheat consumption accounts for the increasing landscape of multiple autoimmune conditions, especially type 1 diabetes in children (and, now, adults), Hashimoto’s, and inflammatory bowel diseases.

So what is it about modern wheat that can cause such misguided immune responses? There are several reasons:

Increased intestinal permeability–Dr. Alessio Fasano and his team, working at the University of Maryland (now at Harvard) have worked out the complex path by which gliadin, when remaining intact, opens the “tight junction” barriers between intestinal cells, allowing foreign substances entry into the bloodstream and thereby organs. Among the substances that can enter: intact gliadin, gliadin-derived peptides, wheat germ agglutinin (a large and highly inflammatory protein), lipopolysaccharide from bacterial cell walls, and others.

Gliadin peptide toxicity–While some gliadin remains intact, some also gets degraded to peptides. Some of these peptides can enter the bloodstream to exert opiate effects on the brain, while other fractions are toxic to the intesinal lining.

Wheat germ agglutinin–Humans cannot digest the roots, stalk, leaves, or husk of wheat because it is a grass. For that reason, humans only consume the flour ground from the seed of wheat. We can only efficiently digest the amylopectin and amylose of the seed endosperm, the carbohydrates. Wheat germ agglutinin of the seed, a component of all wheat flour, is an example of another indigestible component of this grass. This large 4-part structure is highly toxic to the intestinal lining, causing complete denuding of the villi in experimental models. If it gains entry to the bloodstream, it is a potent activator of the immune system.

Molecular mimicry–As if this wasn’t already strange enough, there are amino acid sequences in the gliadin protein of wheat (and thereby the secalin of rye, the hordein of barley, perhaps the zein of corn) that look just like sequences in some human proteins. To date, human proteins that resemble gliadin include transglutaminase (in muscle, liver, many other tissues), synapsin (in nervous tissue), and calreticulin (ubiquitous). The gliadin sequence activates an immune response, which can then launch an attack on the organs containing these cross-reacting proteins.

Dysbiosis–Wheat changes bowel flora, not uncommonly causing dysbiosis, or changes in bowel flora characterized by decreases in healthy species, such as Lactobacillus and Bifidobacteria, and increases in pathogenic bacteria, such as E. coli and Clostridium difficile. Dysbiosis increases intestinal permeability, especially to the lipopolysaccharide component of bacterial cell walls, a powerful activator of inflammation.

Note that NONE of these phenomena leading to autoimmunity require the presence of celiac disease or gluten sensitivity. The abnormal intestinal permeability induced by gliadin, for instance, develops in 80-90% of people; the toxic effects of wheat germ agglutinin affect everybody.

Anyone diagnosed with an autoimmune condition should avoid wheat, as well as its nearly genetically identical brethren, rye and barley (identical gliadin and wheat germ agglutinin sequences), as well as corn (some overlap of corn zein with gliadin) and rice (identical wheat germ agglutinin).

Also, vitamin D restoration (e.g., achieve a 25-hydroxy vitamin D level of 60-70 ng/ml or 150-180 nmol/L), omega-3 fatty acid supplementation, and correction of disrupted bowel flora (prebiotics, naturally fermented foods, prebiotics) are all crucial steps in maximizing your hopes of reversing your autoimmune condition.