Talking with the Experts: Katherine Reid, PhD
I personally wanted to share with you that this post is by far our favorite, we hope you dedicate the time to fully read it and enjoy it. Meeting Dr. Reid back in May has been a very interesting and fun ride for Mission Heirloom, filed with learnings about food, which brought several changes to our menu and allowed cooking techniques. Some of us that have ventured into trying to seriously lower the free glutamate consumption in our diet, have experienced tangible improvements in our health issues that we couldn’t figure out before, so her cause has become a core standard for MH!
Those of you who have been following our work over the last several months have heard us mention the words “free glutamate” on many occasions. We’ve told you that we’re working hard to reduce its presence in our food, and today we explain what that means.
Free glutamate is a molecule that comes from proteins in our food, and it can be elevated when proteins are processed. Why is that a problem? And why should I care? Our friend and admired scientist, Dr. Katherine Reid sat down with us to explain the science.
Katherine Reid is a biochemist based in Silicon Valley, and she is doing amazing research about the relationships between free glutamate, MSG, and our food. She discovered that removing excess free glutamate from her daughter’s diet completely eliminated her autistic symptoms. While tinkering with her daughter’s diet, she learned that excess free glutamate can be associated with all kinds of other health issues — not just autism.
Honestly, it was a pleasure to sit down and drill her with some questions, to provide you with as much information as possible. Feel free to go to her website and enjoy her TED talks as well. Also at her Non-for-profit website she shares a comprehensive list of ingredients to watch. Unfortunately, the food industry is very smart, and there are no regulations that mandate to disclose levels of free glutamate created by processing food, only for “added synthesized MSG”. In the same way the Japanese discovered how some cooking techniques resulted in Umami, the “fifth flavor” – nothing else than free glutamate; so did our food industry. Therefore the excess that is affecting all of us today in so many levels.
We couldn’t be more excited to share Katherine’s story and findings with you today!
Yrmis and The Mission Heirloom Team
DEFINING FREE GLUTAMATE
Before we share our Q&A, we’d like to define a few terms for you:
Protein: Proteins are large biological molecules consisting of one or more long chains of amino acids. Meat, eggs, dairy, legumes, nuts, seeds are all high in protein.
Amino acid: Amino acids are the molecular building blocks of proteins. They consist of anywhere from 10 to 40 atoms, which are mainly carbon, hydrogen, and oxygen. Every amino acid must contain at least one nitrogen as part of an amine group (NH₂); it is this group of atoms that give amino acids their name. Each protein molecule can contain up to hundreds of these molecules, and many proteins consist of a wide array of different amino acids.
Glutamic acid: Glutamic acid is a non-essential amino acid (meaning, we can make it in our bodies in small amounts). It is found in many different proteins, and is found in high concentration in gluten and casein (a protein in dairy).
Glutamate: Often referred to interchangeably with glutamic acid, glutamate occurs when glutamic acid is bound to an anion or salt. Glutamate is an excitatory neurotransmitter, which means it helps to regulate the excitatory pathway in our brains and in the rest of our nervous system. The excitatory pathway is responsible for things like the release of adrenaline, the control of moment, and the expression of thought. It works in tandem with the inhibitory pathway, which calms and relaxes the body and brain.
MSG: MSG is the abbreviation for an unbounded molecule of glutamic acid and sodium, frequently used as a flavor enhancer. MSG is also often referred to interchangeably with glutamic acid and glutamate.
NERD OUT WITH KATHERINE REID
Mission: Heirloom: Why have you focused your work on free glutamates? How did you make the link between these molecules and autism?
Katherine Reid: At the age of three, my daughter was diagnosed by clinical psychologist as being on the autism spectrum. Like many parents, I didn’t really understand what autism was. I found myself faced with a child who clearly had very strong learning disabilities, was struggling in school socially and communication-wise, and was not even able to request things for her survival. It was definitely a serious illness and like many parents, I was trying to figure out answers. The medical community sent me on the path to a behavioral therapy approach. We did try that, but I found that it didn’t work for Brooke. However, when I made small little changes in Brooke’s diet, I could see changes in her behavior and I pursued dietary change further.
Initially, we just increased nutrients to make sure that we weren’t dealing with a gross nutritional deficiency. She began to initiate eye contact. She seemed a little bit more interested when people spoke and a little bit more attentive when people called her name. Before that, it almost seemed like she was deaf because she was so unresponsive to her name and to other people. So I started to explore food a little bit more and decided to take out gluten and casein (a protein in milk) because a lot of parent’s anecdotal experiences saw some improvements in their child’s behavior when they removed these proteins. I wasn’t sure why removing these two proteins showed benefits, but I was willing to test it and see if we saw any change. If we didn’t, I thought that we could certainly put those foods back in the diet.
When we removed gluten and casein (GF/CF diet), we saw significant improvement. Her communication seemed a little bit better and her social behavior seemed a little bit better. There were fewer sensory issues. The world didn’t seem to be over-stimulating her to the point where she was constantly covering her ears. She still had sensory issues, though, and we were still dealing with a special-needs child. It was clear that on the GF/CF diet alone, we couldn’t envision how she could be mainstreamed in a traditional classroom.
From there I actually started to really probe into the connection between gluten and casein. Why were we seeing some improvements by removing these proteins? What should I be looking at? What’s the common theme? My background in protein science came in handy, and I started looking at the amino acid content of both classes of these proteins. I found out that over 25% of both of their protein structures (or amino acid compositions) are made up of the amino acid glutamate. Then I started thinking about the fact that casein and gluten in our diets are more often consumed in a non-raw, processed state. Breads, cheeses, yogurts, and snack foods all contain these proteins in a very processed state. In fact, you don’t normally eat wheat raw. With casein, raw milk is about the only example of a food item that’s completely unadulterated and unprocessed. So that’s when I started wondering if the problem had to do with the actual degradation of the proteins and the release of large amounts of freed glutamate into the body due to food processing. When I started doing more research, I started to come up with a bunch of scientific articles linking excess glutamate to a number of different chronic illnesses, not just autism. A simple google scholar search of glutamate disease provides over 600,000 references.
Glutamate can bind to various receptors in our bodies. It can activate our nervous system because it’s an excitatory neurotransmitter. In other words, glutamate is a chemical signal for our nervous system. I learned that if consumed in excess, the signals for important glutamate-mediated metabolic functions could be completely over activated and desynchronized. This overactivation and desynchronization is associated with some of the traits of autism. Then I thought, ‘Gosh, this really makes sense scientifically.’
So I started exploring and diving into the question of where free glutamate is found in our food. I really had to dive in deep into how particular foods are made, how they are being manufactured, what the processing procedures are, and what additional ingredients manufacturers could be adding that would degrade proteins and free the glutamate molecules from their protein structure.
Once I felt like I had come up with a really good first stage plan at taking MSG out of the diet, I gave it a try. I noticed improvements in my daughter’s behavior very quickly. There were some things that took a little bit longer for her to catch up on, but now she understood social rules, and now she was absorbing information. Her anxiety just completely dissipated. Her sensory issues were no longer there, and her tantrums that were extreme even on GC/CF went away. She was a more focused child, she was much more attentive, and she just seemed much more happy because she wasn’t riddled with anxiety and sensory overload. These were changes that we saw fairly rapidly. Within three months, I would say that we were out of the woods and were no longer dealing with a child that was on the autism spectrum.
Initially, I didn’t know if there was some specific gene mutation or some other familial inheritance that was happening with Brooke or if this approach was broadly applicable to other people. I decided to share this discovery by word of mouth. People shared their experiences with the diet, and I had people reporting back with all sorts of improvements. The degrees of improvement varied depending on the individual. I honestly think that is because people implement the approach in various ways.
When I started my nonprofit, Unblind My Mind, I was able to help many more people. I was able to figure out what was plaguing people, and what was causing them to only commit some part of the way. There is a lot of MSG in our comfort foods and it’s challenging for parents or for people who are taking it on themselves to get rid of all of the foods that they are addicted to. But there have been only one or two people that I’ve heard from who didn’t respond at all. I honestly wonder how that implementation went. You never know if they implemented it correctly or if they adhered to it long enough to really see a change.
MH: Can we back up a little bit and talk about the difference between free and bound glutamate? How do they function in the body?
KR: We refer to glutamate as “bound” when it is in a protein. Free glutamate is just what it sounds like — it’s free to react. It is just the free amino acid. Free glutamate can bind with receptors right on our tongue and these signals are transmitted throughout the nervous system. Glutamate is part of the signaling that goes on to inform the body about how much protein it can expect and to prepare our body for protein digestion. But when you eat it in a free form and it’s not accompanied by the amount of protein that would normally accompany that level of glutamate, you’re sending your body false signals. It also over-excites the nervous system if it is in excess levels. Your digestive tract and your nervous system can become out of sync from excess free glutamate signaling.
Whole protein digestion occurs down a very different track. On the tongue, the protein does not react at all. When it goes down the digestive tract and lands in the stomach, the protein is partially digested. What comes out of the stomach and moves into the small intestine are small peptide chains made up of two to three amino acids. If we don’t need a particular amino acid, the enzymes that are responsible for breaking them down into individual free amino acids won’t be released and that amino acid will be eliminated from our body. If we do need the amino acid, our bodies release the enzymes responsible for breaking down the peptides containing a particular amino acid. When glutamate is eaten in bound form in unprocessed proteins, we can control the amount that is absorbed across the intestinal barrier into the bloodstream, and we can control how much is eliminated as waste.
This does not happen with free glutamate. Free glutamate bypasses all of the correct signals and gets absorbed into the blood in surges associated with food content. When it reaches the small intestines, it doesn’t need to be broken down, so it is quickly absorbed. Free glutamate can actually saturate transporters and impair transport for other similar amino acids. When that happens, we can have deficiencies in these amino acids because their receptors have been swamped out or saturated by free glutamate. In addition, the number of receptors on a given cell is related to the environment to which it is trying to respond. When there’s an excess of free glutamate, your cells respond by expressing additional glutamate receptors throughout our body to respond to the level of glutamate.
For example, there are glutamate receptors that are responsible for insulin secretion. When you start to increase the number of glutamate receptors, you increase the amount of insulin that is secreted when glutamate binds to these additional receptors. If you continue to have heightened insulin secretion over a period of time, you can develop insulin resistance and metabolic syndrome, diabetes, and other the brain issues that are associated with offset insulin levels.
MH: What would you say are the most common sources of free glutamate in the average American diet?
KR: In the western diet, it is mostly found in the processed foods containing protein. When you have a protein and it undergoes a number of different processes, such as acid hydrolysis or enzymatic transformation, you start to hydrolyze the peptide bond and it frees the glutamate molecules. There are a lot of additives that can contain free glutamate: natural flavors, yeast extract, and those sorts of things. When you look at snack products, those typically contain not just one but multiple ingredients that contain MSG. The total MSG in those foods starts to build up. If you look across the entire diet, processed foods contain by far the most MSG.
But then there are things like cheese. People think of cheese as natural. Maybe in its beginnings it was natural, but now the food industry controls the fermentation process — controlled and natural fermentation are opposites. When you try to control fermentation processes for absolute consistency batch after batch, which is required by regulation, you start to loose some of the naturalness of the process. With cheese, manufacturers have selected cultures with specific metabolic properties that will increase the amount of free glutamate generated because it provides cheese a flavor. We don’t know how cheese manufacturers grow a lot of their cultures, so the consumer is left not knowing what strains are used and how the food may have been manipulated to create free glutamate. Cheeses like Parmesan that are more processed and aged, contain more MSG. But you can even enhance that amount four-fold depending on what cultures you use. So there might be even variation across different Parmesans depending on how it’s processed.
MH: Would homemade cheese made from raw milk have less MSG than the cheese that you buy at the store?
KR: Well it depends on what cultures you use, too. So if you’re using a culture from a farm that actually makes their own cultures, then that’s a much better outcome than something that’s been intentionally manipulated to hydrolyze or degrade the protein.
MH: How does the free glutamate content in these processed foods you’ve mentioned compare to the free glutamate content in whole foods like tomatoes and mushrooms?
KR: That’s where I think we need to use some sort of relative scope. The amount of free glutamate naturally found in a tomato is reported to be 0.1%. But the tomato isn’t the issue. If you only ate tomatoes, maybe you could get a little bit of an excess. However, if you’re eating tomato and cheese on a big doughy yeast-risen pizza dough with a bunch of salami and pepperoni, you’ve got a pizza laden with MSG. The problem is the excess. That’s when glutamate becomes an issue. By just eating a whole food diet, glutamate levels would not be in excess.
Whether people realize it or not, people consuming the Western diet are reacting in some way or another. It’s sometimes quite ironic when people will sit there and say, ‘I’m not reactive to MSG,’ but then they’ll complain about frequent headaches, anxiety, or that they’re 100 pounds overweight. There are many ways in which excess glutamate manifests ill effects on people.
MH: When if you have an excess of glutamate, what happens when these signals reach the brain? What happens in terms of over-stimulation? Do you have some examples of symptoms that could happen?
KR: Let’s first discuss how glutamate impacts the brain. We are now becoming much more savvy as scientists about the gut-brain axis, so we know that glutamate doesn’t even need to cross the blood-brain barrier to have an effect. Our brain can get these signals transmitted from the gut. Going back to the insulin secretion example, glutamate, once again, doesn’t need to move into the brain for it to have an effect. Insulin does cross the blood-brain barrier, as does glucose, so the increase in free glutamate can start to upset the balance of glucose metabolism in the brain cells. Then brain cells can release free glutamate in the brain in the extracellular space in response to insulin crossing the blood brain barrier.
If someone has a permeable intestinal barrier, it can translate to a permeable blood-brain barrier because of increased inflammation. Once you have permeability of the blood-brain barrier, glutamate can pass more freely from the blood, into the brain, and cause a negative effect.
Healthy brain cells contain quite a bit of glutamate, but if it’s released outside the cell into what’s called the brain’s extracellular space (where neurotransmission takes place), it can cause problems. Any small increase in levels of extracellular glutamate can initiate excitotoxicity. In this way, the brain becomes over-stimulated. It results in problems like anxiety or sensory overload.
MH: Do you think that glutamate is a factor in developing intestinal permeability?
KR: Yes. We do have glutamate receptors in our intestinal barrier so there has to be some regulating function there. One of the functions of the cells in our nervous system and in our digestive tract is to report about their environment to our brain and to the rest of the body. These cells (glial cells) report on the gut environment by releasing signals from its cells, and one of its signals is glutamate. So if it senses a stress response, like inflammation from glutamate itself, it releases more glutamate to send the stress signal throughout the body. Then the glial cells, which are the cells that are responsible for protecting the intestinal barrier, start to die off. So you can get permeability because of the inflammation associated with excess glutamate levels. Glutamate levels and inflammation are directly correlated. Glutamate initiates the inflammatory response.
MH: Wow. So could free glutamate be part of the reason that we associate gluten with intestinal permeability?
KR: I think that gluten can have different issues for different people. Some may be reacting to the actual protein, but I do think that people who feel better by removing gluten could be feeling better because they’re removing a lot of MSG and therefore inflammation. Intestinal permeability can come from a lot of different factors, but I know that glutamate is one of them.
MH: How concerned should we be about freeing bound glutamates when cooking in our own kitchens? Even if we aren’t using processed foods, what are some ways that we can reduce the problem?
KR: If you’re starting from whole foods and good quality meats, then the primary way that you might introduce free glutamate in the kitchen would be if you’re adding a lot of vinegar or using high, extreme heat to cook any food high in protein. The longer the food is subjected to low pH conditions (acidity) or high heat, like wok cooking or high-heat skillet cooking, the more free glutamate you can create. Roasting and sautéing meats doesn’t create a lot of free glutamate because the peptide bonds in the proteins are fairly resistant to heat. Chemical processes are what really catalyze and speed up that reaction. Adding a little bit of lemon as a flavoring in meat is not going to free up glutamate because that’s not going to lower the pH significantly at all. (this is referring to after the meat is cooked)
MH: We know that there have been a lot of questions about the free glutamates in bone broth. What can go wrong there?
KR: It would be interesting just to test this specifically, but I would suspect that the bone broths that are cooked for a long time, like 24 hours or longer, will start to free up glutamate. The longer the broth is cooked, the more free glutamate it’s going to have. And how much is that? I don’t know. Some people who feel that they are very sensitive to free glutamate will react to bone broth regardless of how much it has been cooked.
So I’m not quite sure how much free glutamate is released. But the gelatinous state seems like it would have more free glutamate than a six-hour simmering of the bones. My guess is that once the broth hits a gelatinous state, the proteins change significantly, and many things are extracted from the bone and skin of the animal. Commercial bone broth always has added additives and so that’s a different story!
MH: What about adding vinegar? Why do you caution against that?
KR: The vinegar lowers the pH of the broth and hydrolyzes the proteins in the bones and skin of the animal. That will degrade the proteins. Again, you’ve got long periods of time of heat on top of low pH conditions. The more vinegar, and then the longer that it is heated, the more free glutamate there’s going to be in the bone broth.
MH: So the vinegar just kind of speeds up what would happen if you cooked the broth for a really long time?
MH: What about vinegars in general? Is there anything about vinegars themselves that can be potentially problematic, even if you’re not adding them to bone broth or other proteins? For example, why would it be more problematic to use vinegar in a salad dressing than a lemon?
KR: It all comes down to which food was used to make the vinegar. There are different ways that you can make a vinegar, but in its most basic form, vinegar is acetic acid that is made from alcohol that is, in turn, made from sugars. Many times, the ingredients used to make vinegar are things like rice, wheat, or corn, which naturally contain protein. The more protein that’s there, the more free glutamate that’s going to be a part of the final product. Apple cider vinegar is different. Apples probably have the least amount of protein of any food that is made into vinegar, therefore apple cider vinegar would likely have the least amount of free glutamate out of all the types of vinegars out there. If you don’t know how it was made, you can guess that it’s probably a very cheap commodity like corn or wheat and can contain glutamate as a contaminant.
MH: Who needs to be concerned about free glutamates? Are they only a problem for people who are sick or who suffer from neurological conditions? Or do you think that everybody needs to pay attention to their intake?
KR: I think that everyone needs to pay attention. I ended up going on the MSG-reduced diet because I wanted to experience what my daughter was experiencing and have her feel like I was supporting her. I was 40 years old at the time and never would have said I was sensitive to MSG.
I was completely surprised about the health benefits. I completely eliminated my pollen allergies and I shed weight without trying. Before the diet, I had these low-level headaches all the time. I didn’t even realize that they were there until they weren’t. When they went away, my whole head felt so much less pressure. As it turns out, glutamate can trigger mucus production in the digestive tract and the increased mucus production was leading to my sinus pressure and these low-level headaches. Before we changed our diets, I had no idea that the headaches were due to free glutamate in the food.
So I think that everybody should be aware about free glutamates in their food because they can impact people differently. There are just so many people in this country with allergies, asthma, obesity, diabetes, digestive issues, and autoimmune diseases. While lowering glutamate may not get rid of an autoimmune disease, it may reduce the inflammation to help you manage it better. I try to encourage the whole family to sign up because they will be amazed at some of the benefits that they had no idea were associated with their food.
MH: So do you think that there’s a healthy amount of free glutamate?
KR: Any time somebody is buying packaged food or going out to eat, they’re probably eating an excess of free glutamate — restaurants are big huge black boxes in terms of what they’re putting into food. They want customers to come back and they’re lucky they don’t have to present a label of exactly what’s in the food and how it’s been made.
I encourage people to be aware of labels. Every time you go to a store and pick up a packaged food and you see an ingredient like ‘natural flavors,’ you should think, ‘What’s a good substitute?’ Or stick to things like produce. I don’t have to train people on how to read labels when it comes to a head of cabbage or a bunch of broccoli. Those just need to be organic. Produce, fruits, vegetables, nuts, seeds, and legumes in moderation are fine. I don’t follow the paleo diet, so I include grains other than wheat in moderation. And then good quality meats, again, should be eaten in moderation. If people don’t have chronic issues, then that is a really good diet.
MH: We know you have a book coming out soon. Could you give us a little preview?
KR: In the book, I tell the story of exactly what we tried with our daughter and how I landed on MSG. I also talk about where it is hidden in food and how everyone can be a better food detective. I present food facts so that everybody has enough information to become their own detective. Then I really go into the science. This is something that I’ve spent the better part of the last four years really diving into.
There are a lot of naysayers out there that will say, ‘Oh there’s been a clinical study that found that MSG is safe.’ But in these studies, they were testing MSG and looking for an allergic reaction. It gets down to semantics here as to what exactly an allergy is. Glutamic acid or MSG does not cause an IgE-mediated reaction, meaning it doesn’t raise antibodies like an allergy to a pollen would. It’s a small chemical and its reactions are different. So they had all of these allergists looking at clinical trials to examine MSG safety, and they were looking for an allergen-induced response. When they didn’t see it, they assumed MSG was safe. They didn’t look in the right place. I talk about these studies in the book just to say what’s been done and why most scientists are not really viewing the safety of MSG correctly. I also address the fact that we have an epidemic of glutamatergic excess and disfunction, from Alzheimer’s disease, Parkinson’s, and multiple sclerosis to diabetes-related issues. There are many scientific studies demonstrating the links between excess free glutamate and these diseases, but most of these studies don’t hypothesize as to where the excess glutamate is coming from. To me there’s no mystery of where this glutamate excess is coming from. Let’s not be silly — it’s coming from the food.