According to the author, Dr. Blaylock, "Excitotoxins" are special amino acids, such as glutamate and aspartate (which are commonly found in MSG and Nutrasweet). These "Excitotoxins" are added to processed food to enhance the taste. Normally they act as neurotransmitters in the brain and spinal cord. However, when these common food additives are consumed (by eating certain processed foods) excessive amounts can develop which kill certain neurons in the brain by causing them to fire repeatedly (and needlessly) until they die.

How do they do this? Dr. Blaylock explains that there are two problems. First, we must understand that glutamate is normally in the brain and use to signal a neuron when it is time to fire. When it is done there is a cellular mechanism which transfers excess glutamate back into the surrounding glial cells. The glial cells encase the neurons in the brain and supply them with energy (in the form of ATP). The amount of energy required to do this is very high. This points to the first problem which is that in a hypoglycemic (low blood sugar) condition there is not enough ATP present to transfer the glutamate. In the constant presence of glutamate the neurons fire repeatedly until they die.

Specifically, as a part of the signal process, glutamate and aspartate act as a sort of key to unlock calcium channels into the neuron which chemically initiate the neurons to fire (their normal task). The cellular calcium pump turns on which remove the calcium. This is the second problem. The calcium pump requires a tremendous amount of energy also. In a hypoglycemic condition these calcium pumps fail to operate allowing the neurons to fire repeatedly until they die.

The solution may seem to be to eat more so that there is never a hypoglycemic state. This may seem possible, but the reality is that (as Dr. Blaylock points out) the FDA has allowed the food industry to include these "excitotoxins" in so many hidden forms that the consumer may not be aware that they are actually eating the same substances that they usually try to avoid (MSG.) This massive consumption of glutamates and aspartates may be impossible to overcome with normal brain processes. A diet rich in natural unprocessed foods is very important.

The only true solution is to avoid consuming "excitotoxins." Dr. Blaylock points out in Appendix 1 other common food additives which have hidden sources of MSG. These include: Hydrolyzed Vegetable Protein, Hydrolyzed Plant Protein, Hydrolyzed Protein, Sodium Caseinate, Calcium Caseinate, Yeast Extract, Textured Protein, Autolyzed Yeast and Hydrolyzed Oat Flour. Some food additives may have MSG include: Malt Extract, Malt Flavoring, Bouillon, Broth, Stock, Flavoring, Natural Flavoring, Natural Beef or Chicken Flavorings and seasoning.