What is glutamate
Glutamate is the most common excitatory neurotransmitter and the most abundant amino acid in the brain. Glutamate is necessary for normal brain function, learning and memory. Although glutamate is a necessary neurotransmitter, more is not better. Too much glutamate wreaks havoc in the brain, exciting cells to death in a process known as excitotoxicity. High levels of glutamate have been associated with increased pain. Excitotoxicity has been linked to strokes, Alzheimer’s disease, seizures and autism.
Where does glutamate in the diet come from?
The body can make its own glutamate. Therefore, there are no dietary recommendations or requirements for glutamate. Glutamate is both natural and synthetic in our food supply. There are two types of food sources for glutamate; bound glutamate and free glutamate. Bound glutamate is present in varying amounts in all protein-containing foods. Most people do not react to bound glutamate. However, some people benefit from reducing glutamate-rich foods. Free glutamate is not bound to other amino acids, making it a highly concentrated and stimulating source of glutamate. An example of free glutamate is MSG, or monosodium glutamate, a synthetic form of glutamate.
MSG is a synthetic food additive and flavor enhancer found in almost all processed foods and some restaurant kitchens to impart an umami flavor to foods (the fifth basic taste). Any MSG should be avoided completely as it has been linked to endocrine disruption, migraines, heart palpitations and a cluster of symptoms known as ‘Chinese Restaurant Syndrome’. There are many sources of hidden free glutamate, even in “healthy” snacks found in health food stores. Watch for ingredients such as “hydrolyzed” foods like “hydrolyzed protein”, yeast extract, monopotassium glutamate, textured protein, soy protein, and/or whey protein. All of these may be hidden sources of MSG. Some otherwise healthy foods are naturally high in free glutamate, including oysters, wheat/gluten, tomatoes, potatoes, mushrooms, aged cheeses, and peanuts.
Glutamate and GABA
GABA and glutamate have an important relationship because GABA is made from glutamate. Glutamate is the main excitatory neurotransmitter while GABA acts as the main inhibitory neurotransmitter. They help keep each other balanced. If glutamate had excess personality, it would be angry, irritating, and irrational. If GABA had a personality type, it would be cool, calm, and carefree. We can see how these qualities make them more effective as a team. When one or the other takes power over the other, the brain becomes confused.
When glutamate is low
Low glutamate is rare. Symptoms of low glutamate can include insomnia, concentration, mental exhaustion and low energy, but it’s also a signal that the gastrointestinal tract may be in distress. Supplementing with glutamine and including foods that are naturally high in glutamate will help restore glutamate levels.
When glutamate is high
Symptoms of high glutamate can include headaches, anxiety, irritability, restlessness, and ADHD-like symptoms. MSG and other food additives containing glutamate should be strictly avoided. The ingredients below are examples of food additives containing glutamate:
- Anything Hydrolyzed
- Sodium caseinate
- Yeast extract
- Autolyzed yeast
- whey protein
- soy protein
- Soy Protein Concentrate
- Soya sauce
- Glutamic acid
When glutamate is high, also consider reducing foods naturally high in free glutamate such as wheat/gluten, barley, peanuts, diet drinks. Foods to focus on may include: pasture-raised chicken and eggs, legumes, wild-caught fish, quinoa, avocados, leafy greens, rice, sweet potatoes, whole fruits, herbs and fresh or dried spices. Support GABA levels (link to GABA article) through proper diet, targeted supplementation, and lifestyle modifications. For example, the practice of yoga and meditation have been shown to benefit GABA levels.