All grains produce lectins, which selectively bind to unique proteins on the surfaces of bacteria, fungi, and insects. These proteins are found throughout the animal kingdom. One protein in particular for which WGA has an extremely high affinity is N-Acetylglucosamine. N-Acetylglucosamine richly adorns the casing of insects and plays an important role in the structure of the cellular walls of bacteria. More importantly, it is a key structural component in humans in a variety of tissues, including tendons, joint surfaces, cartilage, the lining of the entire digestive tract, and even the lining of the hundreds of miles of blood vessels found within each of us.
It is precisely the ability of WGA to bind to proteins lining the gut that raises concern amongst medical researchers. When WGA binds to these proteins, it may leave these cells less well protected against the harmful effects of the gut contents.
WGA may also have direct toxic effects on the heart, endocrine, and immune systems, and even the brain. In fact, so readily does WGA make its way into the brain that scientists are actually testing it as a possible means of delivering medicines in an attempt to treat Alzheimer’s disease.
It's hard to know how real these "may" statements are, but once I committed to near elimination of wheat from my diet, I'm glad I have. The changes from wheat elimination were subtle, and the changes in my health over the last 6 years have been profound, and I'm not sure which health changes to attribute to which food changes. All I can say is it is certainly a thing to be concerned with and to experiment with if your health is not what you wish it were.