Low Glutamate Diet
by Sue Kira, Naturopath & Clinical Nutritionist
Glutamate is an amino acid from protein that is a natural and essential part of many common foods that we eat. It can be found in a ‘bound’ form, where it is part of an unmodified protein, and is generally digested slowly, to be used by the brain and gut for healing, repair and stimulating our nervous system.
However, it can also be in an ‘unbound’ or ‘free’ form, where it is no longer bound to an amino acid, so it is then digested and absorbed faster by the body, creating a spike of glutamate in the blood which can create damage to our nervous system and beyond.
While free form glutamate can be found in many natural foods, it is also commonly found in additives in many processed foods with ‘disguised’ names that we will see later in this article. One of the well-known free form glutamates is the additive MSG (mono-sodium-glutamate).
Many people have a sensitivity to glutamate and a higher percentage are children as they have under-developed myelin sheaths, which is the protective coating around nerves (like insulation on wires) which makes them more prone to the stimulating effects of glutamate.
Symptoms of glutamate sensitivity can include headaches, tummy upsets, behavioural disturbances, anxiety and even asthma attacks, which can occur immediately, or even after many hours of digesting glutamate containing foods.
For a long time, I wondered about the difference between glutamine and glutamate. My research showed many varied responses, with many citing the virtues of glutamine, and even glutamate as being beneficial.
As a practitioner, for years I have used glutamine powder or glutamine rich foods to help heal leaky gut and inflammatory conditions (especially of the gut) with great success. But it seems that some people are genetically predisposed to being more sensitive to glutamates and can also convert more glutamine to glutamate than is needed by the body, which hyper-excites the brain and the nervous system.
Glutamine in food is usually drip fed to the body, and through a series of biochemical processes, converted to glutamate daily as needed for repair and regeneration, and to serve the nervous system so that it can function properly.
Glutamate’s role in the body is to stimulate our brain cells to deliver messages throughout the body and is particularly important for memory, learning, and general growth and development of the brain, especially for children. Glutamate is considered to be an excitatory neurotransmitter or a stimulant and very necessary at times in the right amounts.
Another name often associated with glutamine and glutamate is glutamic acid, which is essentially the same as glutamate. I mention this because you may see this name if you research this topic, and it can get confusing when different names are used.
Glutamate is essential for life, but there are many people who are sensitive to it. By reducing their brain’s exposure to glutamates, they can reduce the over-stimulation of their brain cells and reduce or remove symptoms.
Conditions/symptoms that have been helped by reducing glutamate exposure include:
- Atrial fibrillation
- Behavioural issues
- Learning disorders
- Panic attacks
- Restless legs syndrome
- Also see the following list…
Another neurotransmitter called GABA (gamma-amino-butyric-acid) is the calming, relaxing neurotransmitter that creates balance between the two neurotransmitters (GABA and Glutamate). Keeping a balance between the two is very important otherwise an excess of glutamate over time can cause neurological damage and inflammation to the nerves, which can also lead to neurodegenerative conditions such as:
- Alzheimer’s disease
- ALS (Lou Gehrig’s disease)
- Epileptic seizures
- Multiple Sclerosis
- Huntington’s disease
- Parkinson’s disease
The body normally keeps all the neurotransmitters balanced in the brain, but for some this doesn’t always happen. One of the reasons that we see the above lists of symptoms occurring is when people (especially children with underdeveloped nervous systems) eat foods and additives that contain the nervous system stimulants glutamate and aspartate, another neuro-stimulant.
For most people, food sources are not the issue, but food additives that contain these substances can become a big issue. Initially, some people may need to lower the amount of nervous system stimulants from all sources, and then reintroduce the natural food sources as far as can be tolerated, and then adjusted according to symptoms.
I mentioned aspartate, another excitatory neurochemical. Aspartate is found in food and drinks as an artificial sweetener additive (aka aspartame or aspartic acid). Aspartate can enter the same receptor site (parking space) as glutamate to affect the neurones and create excess firing of the nervous system and result in damage to the neurones.
A diet avoiding glutamates and aspartates is used to help reduce epileptic seizures and many of the symptoms listed above.
Apparently, glutamate and aspartate consumed together can have even more harmful effects on the nervous systems of young children because of the incomplete myelin sheaths of their nervous system.
We don’t have to look to far to see children eating foods such as processed meats like ‘devon’ or similar, or foods with MSG (2-minute noodles for example) plus a ‘no added sugar’ drink that contains aspartate (diet cola/soda) and as a result have hyperactivity, attention deficit or behavioural issues.
Together, these two stimulants have a far greater capacity to harm the body than either one alone. Some kids who have been diagnosed with emotional problems or attention deficit with hyperactivity – considered to be ‘problem children’ – are often merely reactive to these substances and removal has made their lives (and those around them) normal.
Some have even seen those diagnosed with autism change for the better on a low glutamate and aspartate diet. There can be more to autism that this alone of course, but anything that we can do to help is a bonus for those involved.
Glutamate, ‘Leaky gut’, ‘leaky brain’ and the blood brain barrier
Our brain is protected by a layer of cells that only allow certain substances into the brain in regulated amounts as needed. In ‘normal’ circumstances, substances like glutamate do not normally cross the blood brain barrier (BBB) to enter the brain. The industrial producers of glutamate tell us this. Mmmm…suspicious?
But this does not take into account entry via the ‘gut brain axis’. If you have ‘leaky gut syndrome’, aka intestinal permeability, from bacterial overgrowth or food intolerances etc, the inflammation in the gut can also make the blood brain barrier ‘leaky’ or more permeable to let substances in that should not get in.
Therefore, the combination of low-grade digestive system inflammation and glutamate sensitivity may combine to create any of the above-mentioned symptoms.
If you suspect that you have glutamate sensitivity, eliminate as many artificial and natural glutamates and aspartates as possible from your diet until symptoms subside.
Later, gradually re-introduce some of the more natural sources of glutamate back into your diet. Carefully note any symptoms that may emerge, and you can then use this information to build a low glutamate diet that suits you best for the long term. Speak to your health provider for further clarification.
Following are food and substances to avoid…
Natural sources of free glutamate to avoid
- Foods matured, cured, or preserved
- Fish sauce
- Soy sauce and soy protein
- Ripe tomatoes and tomato products (tomato sauce, tomato paste etc)
- Grape juice
- Bone broths and meats cooked for long times
- Malted barley used in breads and beer
- Wheat gluten
- Dairy casein
Free glutamate can be disguised as any of the following
- monosodium glutamate
- monopotassium glutamate
- yeast extract
- anything ‘hydrolyzed’ such as hydrolyzed vegetable protein
- calcium caseinate
- autolyzed yeast
- textured protein
- soy protein (including isolate and concentrate)
- whey protein (including isolate and concentrate)
- bouillon and broth
- ‘flavors’ or ‘flavoring’ (i.e. natural vanilla flavor)
- citric acid
- milk powder
- soy sauce
- anything ‘protein fortified’
- corn starch, corn syrup
- modified food starch
Avoid the following foods to elude the excitatory amino acids
While most meats are naturally rich in glutamate and aspartate, in most cases the effect is offset by other amino acids in the meat. However, if you initially want foods that are very low in glutamates, then lamb and eggs have the lowest amount of these natural food chemicals. Chicken is quite low – while rabbit and turkey are the highest in glutamate. (So lamb, eggs and chicken are the best)
The amount of glutamate and aspartate in a normal serving of meat would normally not be an issue. It is usually other additives with meat such as sauces and condiments that are the real problem.
How you cook your meat can also influence how much glutamate is freely available to cause problems. The longer and slower you cook meat, the more free glutamate is present e.g. cooking bone broths, soups and casseroles.
Having said that, bone broths can be great for gut healing. The best way to handle this is to only cook bones with no flesh for the broth, and then add some chopped meat to cook towards the end of the process if you would like a meaty flavour.
Grains, such as wheat, barley and oats are highest in glutamate. Corn and rice are lower, but some people can be quite reactive to corn. The protein ‘gluten’ found in wheat, rye and barley is 25% glutamate. Wow! No wonder these are so bad for so many.
All dairy products are high in glutamate and aspartate. Casein, the protein in dairy, especially in parmesan cheese, is 20% glutamic acid by composition.
The Nightshades family of fruits and vegetables such as tomatoes, potatoes, capsicum (peppers), eggplant (aubergine) and chillies/paprika are best avoided due to their high glutamate levels.
Beans, such as soy, navy, pinto, black, lima beans and lentils are all high in glutamic acid/glutamine. Beware, as soy is incorporated into many products as a cheap protein filler. Soy may be labelled as vegetable protein, textured vegetable protein, or soy isolate.
Seeds such as sunflower seeds and pumpkin seeds (pepitas) and other seeds are generally high in glutamate.
Nuts such as peanuts are very high in glutamate, as are cashews and pistachios, but less so in almonds. Almond butter spread, or a few almonds, are usually okay if eaten occasionally.
Sauces and Condiments
Sauces and condiments are high risk (especially soy based or tomato based) so it is best to season foods with fresh herbs, spices and salt (avoid chilli/paprika).
Diet drinks and foods
Avoid diet drinks and diet foods of any kind that contain any artificial sweeteners such as ‘Nutrasweet’, also called Equal or aspartame, aspartate or aspartamine.
Processed or pre-prepared foods often contain MSG. MSG can be disguised by calling it hydrolyzed vegetable protein, textured vegetable protein (TVP), flavour enhancer or soy protein extract. You will see this particularly in Asian style foods, but it’s not exclusive to them.
Common foods that contain high levels of glutamate as an additive are soups, noodle dishes, like ‘2-minute noodles’ etc. Some don’t even label all their contents, even though it’s illegal not to. (Apparently a certain amount can be used before declaration is required – that’s terrible!)
In most cases nutritional supplements are no cause for concern, however for those who are highly sensitive to glutamates and aspartates, it is wise to avoid supplements that contain glutamine (which can convert to glutamate for some), and to avoid aspartates that are found in mineral supplements like magnesium aspartate, potassium aspartate and the like. There are also compounds like potassium glutamate, which can be great for some, but not for glutamate sensitive individuals.
Alcoholic beverages contain glutamate, especially those using mixers of diet soft-drinks/sodas that also contain aspartates. This can be a ‘deadly’ cocktail of chemicals and sugar (not to mention the alcohol itself).
Stimulating foods and drinks
Chocolate, raw cacao, coffee and tea all contain glutamates as they are fermented foods and have a strong taste. Basically, anything that has a strong flavour to stimulate our taste buds contains glutamates.
Fermented foods of any kind contain glutamates and glutamines.
Chewing gums, mints and binders and fillers in many supplements and prescription medications commonly contain either aspartates, aspartames or glutamates as a ‘sweetener’ or to make the product taste better. Also, beware of children’s medicines that are coloured, flavoured and non-sugar ‘sweetened’.
When you delve into it, you will be amazed where you can find glutamates, MSG and other additives. Glutamates such as MSG can even be found in vaccines, personal care items, food waxes on non-organic fruits, fertiliser and pesticides on our produce, infant formulas (yep there too), protein powders and believe it or not, they can also be found in products claiming to be ‘organic’, or say ‘no added MSG’.
Beware of labelling. Don’t be fooled, keep food simple and natural.
Just removing gluten, dairy products, additives, and processed foods can make a huge difference to the levels of glutamate and aspartates in the diet. Advocating a GF/DF/AF (additive free) diet to my clients over the last 28+ years is a big reason why I have had so many great results and many happy parents of previous ‘difficult children’.
- Most fruits and vegetables are great to eat, including green leafy vegies, root vegetables and berries. Some say to avoid corn but small amounts of very fresh corn are ok. Nightshade family of fruits and vegetables such as tomatoes, potatoes, capsicum (peppers), eggplant (aubergine) and chillies/paprika are best avoided initially. Also avoid mushrooms, peas and broccoli initially or only eat small amounts.
- Lean meats and fish in modest serves. Small amounts of lamb, chicken, and fish ok. Minimal beef is also fine.
- Eggs are a great source of protein that are low in glutamate and aspartate
- Small quantities of unprocessed wild black, brown or red rice.
- Small quantities of nuts and seeds as snacks. Tree nuts such as pecans and macadamias are the lowest. With strong symptoms in conditions such as ADHD, epilepsy, or fibromyalgia it’s best to avoid all nuts and seeds until symptoms settle down.
When symptoms have settled, trial adding these foods:
- Gluten-free grains and seeds such as quinoa, amaranth, sesame seeds and flaxmeal.
- Nuts and seeds. Tree nuts such as pecans and macadamias are ideal.
- Legumes/beans. Continue to avoid soybean products, but some people can tolerate other legumes and beans in small amounts.
- Nightshade fruits (tomatoes) and vegetables (eggplant, peppers, potato) in small amounts provided there are no reactions when re-introduced. Also mushrooms, peas and broccoli can come back into the diet, but be aware of any returning symptoms.
Before you commence your diet, see your medical or health care professional for qualified guidance about what foods and supplements are best for your body. While on the diet do not stop any medications or supplements previously prescribed unless advised otherwise by your medical or health care professional.
During the early stages of a new diet, you may experience symptoms such as fatigue, headaches, or body aches, which may occur because your body is detoxifying. However, if you are unsure about a symptom at any time, check immediately with your medical or health care professional.