Excitotoxins – The Link Between MSG and Huntington’s, Parkinson’s and Alzheimer’s Diseases

Dr. Russell L. Blaylock, the author of Excitotoxins: The Taste that Kills, (Health Press, 1997) continues to draw the link between special amino acids he calls “excitotoxins” (such as Monosodium Glutamate or MSG) and various slow developing neurodegenerative diseases such as Huntington’s, Parkinson’s and Alzheimer’s diseases in chapter 5.

Originally, Dr. Blaylock points out, scientists believed that genetic programming of neurons called for a naturally shorter life span of neurons. However, evidence is pointing to extreme variances in the life span of neurons. For example, Parkinson’s disease symptoms don’t manifest until 80 to 90% of the brain nuclei called substantia nigra have died. These neurons couldn’t have died all at the same time.

Another theory was a neuron killing virus but again the scientific research has failed to make the connection. The same is true with the immune system failure theory. Dr. Blaylock points out that the “environmental toxin as the causative factor” theory (namely aluminum) was the most impressive but still wasn’t the answer. He points out that the presence of aluminum in the brain is not the cause of the neurodegenerative diseases but a result of a susceptibility to aluminum absorption already created.

Dr. Blaylock reports on several curious neurodegenerative cases. One which was that of the Chamorro Indians living on the Mariana Islands who were dying at an alarming rate from a disease similar to Amyotrophic Lateral Sclerosis (ALS). After extensive research it was finally concluded that the safeguards for processing the normally poisonous cycad plant (or False Sago Palm) into flour were slowly abandoned due to food scarcity. This created a long term exposure to a neurotoxin which eventually killed enough neurons to reveal ALS-like symptoms of hand (and then limb) immobility and death. Some of the Chamorro Indians were more sensitive to the toxin than others. Other similar stories were reported with the same symptoms in the Auyu and Jakai people of West New Guinea and people in Kii Peninsula of Honshu Island of Japan.

From these studies Dr. Blaylock concluded that our resistance to these food based neurotoxins depends on several points. First, it depends on the condition of our brain’s protective blood-brain barrier. A compromised blood-brain barrier may allow too many neurotoxins (in the form of glutamates) into the brain causing damage. Second, it depends on the amount of dietary exposure to excitotoxins (such as exposure to MSG and to hydrolyzed vegetable protein). Excessive consumption of glutamates may have a tendency to overwhelm the body’s ability to deal with them. Third, it depends on the metabolic efficiency and the continuous availability of energy for normal cellular pumps to move glutamate from within cells to surrounding glial cells, which encase and supply energy to the neurons. Finally it depends on the presence of free radical scavengers (to remove the free radicals in the brain).

Dr. Blaylock then reports on the research of the effects of amphetamines (also known as “uppers”) on the nervous system, specifically on the similarity of the destruction of the same neurons as with Parkinson’s disease and in the same manner (overworking the neurons to death). He remarks that the ingestion of amphetamines and even the Parkinson’s drug L-DOPA (which is actually a mild excitotoxins and speeds up the disease) shows how the neurons can be chemically forced “on” until they die.

Dr. Blaylock concludes this chapter by presenting replies to a couple major objections presented in regards to the connection of the ingestion of excitotoxins and neurodegenerative diseases. The first objection is that if food toxins and additives were the cause of Parkinson’s disease why wouldn’t all of us eventually develop the disease? Dr. Blaylock’s reply is that first he is not suggesting that food additives are the “primary cause” of Parkinson’s disease or any other neurodegenerative disease. He points out that there is varying sensitivity to any toxin within any species of the same size and sex. He also states that the individual’s ability to pump out the glutamate varies with long term cellular pump condition and consistently available energy. He also points out that rate of Alzheimer’s disease between the ages of 65 and 74 is 3%, between the ages of 75 and 84 it rises to 18.7% and then soars to 47.2% after 85. This shows an age related vulnerability.

The second objection is that if large amounts of glutamate are consumed, the blood-brain barrier will keep the glutamate from entering the brain. His reply is that normally this is true. However, there are numerous conditions in which this barrier may be compromised allowing glutamate to enter such as with head injuries, viral and bacteria infections, hypertension, heavy metal exposure and elevated core body temperature. Dr. Blaylock points out that the most common reason for a breakdown in the barrier is a stroke.

What can one do to avoid this type of neural damage? Dr. Blaylock says that much of the damage is due to the release of free radicals. The most success comes from antioxidants such as vitamin E. L-leucine has been shown to improve neurological function also. Magnesium and zinc intake have also been shown to slow the progress of neurological diseases. However, the best benefit is gained when one avoids 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.