The Toxic Effects of Wheat Germ Agglutinin (WGA)
Wheat contains high amounts of wheat germ agglutinin (WGA); a glycoprotein classified as a lectin, which is largely responsible for many of wheat’s ill effects. Other grains high in lectins include rice, spelt, and rye.
Interestingly enough, the highest amount of WGA is found in whole wheat, including its sprouted form, which is touted as being the most healthful form of all. Aside from high amounts of WGA, wheat also contains a number of other potentially health-harming components, including:
- Gliadin (an alcohol soluble protein component)
- Gliadomorpin (exorphins, or group of opioid peptides that form during digestion of the gluten protein)
- Enzyme inhibitors
The traditional ways of addressing many of these anti-nutrients is by sprouting, fermenting and cooking. However, lectins are designed to withstand degradation through a wide range of pH and temperatures. WGA lectin is particularly tough because it’s actually formed by the same disulfide bonds that give strength and resilience to vulcanized rubber and human hair.
Furthermore, because lectins are so small, and hard to digest, they tend to bioaccumulate in your body, where they can interfere with biological processes. WGA is particularly troublesome in this regard. Studies indicate it has a number of health-harming characteristics and activities:
- Pro-inflammatory–WGA stimulates the synthesis of pro-inflammatory chemical messengers (cytokines) in intestinal and immune cells, and has been shown to play a causative role in chronic thin gut inflammation.
- Neurotoxicity–WGA can cross your blood brain barrier through a process called “adsorptive endocytosis,” pulling other substances with it. WGA may attach to your myelin sheath and is capable of inhibiting nerve growth factor, which is important for the growth, maintenance, and survival of certain target neurons.
- Immunotoxicity–WGA induces thymus atrophy in rats , and anti-WGA antibodies in human blood have been shown to cross-react with other proteins, indicating that they may contribute to autoimmunity. In fact, WGA appears to play a role in celiac disease (CD) that is entirely distinct from that of gluten, due to significantly higher levels of IgG and IgA antibodies against WGA found in patients with CD, when compared with patients with other intestinal disorders.
- Excitotoxicity–Wheat, dairy, and soy contain exceptionally high levels of glutamic and aspartic acid, which makes them all potentially excitotoxic. Excitotoxicity is a pathological process where glutamic and aspartic acid cause an over-activation of your nerve cell receptors, which can lead to calcium-induced nerve and brain injury. These two amino acids may contribute to neurodegenerative conditions such as multiple sclerosis, Alzheimer’s, Huntington’s disease, and other nervous system disorders such as epilepsy, ADD/ADHD and migraines.
- Cytotoxicity—WGA has been demonstrated to be cytotoxic to both normal and cancerous cell lines, capable of inducing either cell cycle arrest or programmed cell death (apoptosis).
- Disrupts Endocrine Function—WGA may contribute to weight gain, insulin resistance, and leptin resistance by blocking the leptin receptor in your hypothalamus. It also binds to both benign and malignant thyroid nodules, and interferes with the production of secretin from your pancreas, which can lead to digestive problems and pancreatic hypertrophy.
- Cardiotoxicity—WGA has a potent, disruptive effect on platelet endothelial cell adhesion molecule-1, which plays a key role in tissue regeneration and safely removing neutrophils from your blood vessels.
- Adversely effects gastrointestinal function by causing increased shedding of the intestinal brush border membrane, reducing the surface area, and accelerating cell loss and shortening of villi. It also causes cytoskeleton degradation in intestinal cells, contributing to cell death and increased turnover, and decreases levels of heat shock proteins in gut epithelial cells, leaving them more vulnerable to damage.