Everyone should have recovered from the post-Thanksgiving food comatose (no, it was not due to the turkey’s tryptophan), the post-election discussion and the Blck Friday melee fight for that 55″ UHDTV that is justin time to play on your XB1S with a 4K resolution.
Seem the woo is never running short of idea, piling up fallacy over another fallacy as iHop piled up pancake in a post-Thanksgiving breakfast ride.
The latest fallacious claim cames from a “nutrition blog” claiming that bone broth, leads to elevated glutamate levels following bone digestion (!), such glutamate results into a leaky gut. Leaky gut means utomtically leaky brain, letting glutamate flows into the brain as boiling pasta water flows through the hole of the pasta strainer and ultimatelly leads to neurological disorders, with a special mention of neurodevelopmental disorders such as ADHD and ASD, because these are two conditions that scares parents as hell nd therefore makes a juicy alibi to milk on parents withtheir precious $$$ and torture kids with dubious or completely scam treatment (including bleach enema, putting kids on casein-free/gluten-free diet, hyperbaric oxygen chamber or chelation treatment).
Because I am the one claiming the claim of this blog post is bogus, it is my duty (and my pleasure as a BBB Scientist) to debunk it.
1. About the bone broth….
In the post, the author first claim that bone broth prepation (slow cooking) results in a dissolution of the tendrils and connective tisues to dissolve, as cited as the following
“So what’s the dark side of Bone Broth? It lies in the “long” part of the “slow and low and long” cook time. Bone Broth simmers at a low temperature for many hours, long enough to allow the connective tissues to dissolve and the minerals to be drawn into the broth.“Thats partially true. Bone broth is composed by two major type of tissue: connective (bones, tendrils, muscles) and non-connective tissue (basically the bone marrow). The preparation of bone broth will primarily dissolve the bone marrow (rich in bone marrow stem cells) that gives that yummy flavor in dishes, my fond being the French “Pot-Au-Feu” (the yummiest soup during the holiday season). The cooking process will tenderize the meat but very unlikely to dissolve bones and tendrils.
To dissolve bones and tendrils, you need something……very acidic. Only an extreme acidic and hot environment will dissolve bones and tendrils. Therefore her first claim is not fully backed by science. Now let’s assume you have some connective tissue that solubilize, you will have mostly collagen dissolved. Collagen is the main protein involved in most connective tissues. The author claims that such processing releases tons of glutamic acid (that is also glutamate) as described here “The result of such long cook times is a tremendous amount of glutamic acid. And that’s the dark side of Bone Broth”
.Collagen is a polymer made of a same repeat motif Glycine-X-Y, with X and Y being often proline and hydroxyproline (the hydroxylation of proline into hydroxyproline is made by prolylhydroxylase, using vitamin C as a co-enzyme. This is why scurvy (lack of vitamin C) is characterized by defect in connective tissues).
It comes with different flavors depending on the function (collagen type I being the predominant form in connective tissue; collagen II found in tendrils; Collagen III in cartilages and bones; Collagen IV in basement membranes……). This second fact discredits her claim that collagen will increase the amount of glutamate.
2. What is the blood-brain barrier (BBB) and how glutamate is processed?
After giving her culinary explanation, the author jumps into explaining glutamate into her own terms: “As you may or may not know, glutamic acid and glutamate are highly regulated by the human brain“. You can already note the red herring about the author as she treats glutamic acid and glutamate as two distinct chemical entities. This is an obvious lack of understading of biochemistry as glutamate is the the ionized (salt) form of glutamic acid. This is a typical misconception that I see with folks peddling on woo (folate/folic acid anyone?). It also raises concern about the credentials of someone making dubious health claims. Garbage in, garbage out.
Not only the author makes blatant mistakes but also makes fallacious associations as mentioned here “If you have a leaky brain, as those with a leaky gut often do, high amounts of glutamic acid can trigger seizures if you’re prone to them. Yes, seizures. It can also trigger other neurological symptoms you may already be sensitive to, including brain fog, migraine headaches, dramatic mood swings, stimming, and nervous tics, to name a few.”
I have been discussing over and over about the BBB in my blog, so I will not repeat over and over again. I will keep it simple. The BBB is what we call a component of the neurovascular unit (a combination of the cardiovascular and nervous system) that is designed to protect the brain from any interferences from the periphery. Therefore the environment in which the brain bathes in is strictly controlled, with a defined composition. The BBB provides two kind of barrier: a physical and a chemical barrier supported by the brain microvascular endothelial cells (BMECs) lining the inner side of blood vessels. They provide a tight blood-brain interface that strictly regulates what comes in and out the brain. The physical barrier is harbored by the presence of tight junction complexes, whereas the chemical barrier acts as a selective filter that pick and choose which molecules goes into the brain through an array of transporters, represented by the super-family of solute carriers (SLCs). Each solute carriers are adapted to let the entrance of specific molecules (for instance SLC2A1 lets glucose enters the brain, SLC16A1 lets T3 thyroid hormone enters the brain….).
In many aspects, BMECs share a lot of features than intestinal cells. But a leaky gut and a leaky BBB cannot explain her claims. In order to understand how her claim is bogus, I will argument using a recent review by Hawkins RA and Vina JR (the first author has a publication records in regards of glutamate transport accross the BBB). If glutamate
However, glutamate is firstly poorly transported inside the brain because it remains trapped inside the BBB . Thats already hit her claim.
If we follow her logic, we are facing a massive increase in glutamate level in the food uptake (due to the broth). Because you have a leaky gut (a concept I have been already explained in my previous blog as still debated and mostly inaccurate in terms of diseases), you have your body flooded with glutamate and ultimatelly flooding your brain with glutamate. This makes sense only if you have a deficit. Chemicals flows into two compartment following the Ficks law, it diffuse from the most concentrated to the least concentrated compartment. Because it is considered as a non-essential amino acid (your body knows how to build it up from other molecules), the brain is not in need for glutamate and can produce its own. Glutamate plasma concentrations range from 50-100microM, brain concentrations ranges from 10’000-12’000 microM. We are talking about 200 times more in the brain than in the plasma. Therefore, you need to achieve a concentration higher in the brain to expect to see any changes. Thats simply impossible and destroy the rest of her argument!
3. But, but…….I have a leaky brain! (No you have not).
The idea of a leaky brain is simply the most ridiculous claim. If your brain was indeed leaky, you would not be here reading this post. You will be six feet under, dead from a massive brain edema.
Leaky brain happens when you have a disruption of the BBB, in particulat from the tight junctions lining BMECs. This results into an onset of “vasogenic cerebral edema” and in an unrestricted entrance of water and ions inside the brain.
This happens if you are experiencing high-altitude mountain sickness (in particular high-altitude cerebral edema), stroke or brain trauma (traumatic brain injury). Because the brain is contained inside a rigid structure (skull), it cannot expand and swell as you would experience if you experience and injury in the periphery. This results in an increase of an intracranial pressure (ICP) and brain injury by mechanical stress (imaging squishing a sponge in your hand) that leads to neuronal cell death. Untreated, brain edema is fatal. However, there are cases of cerebral microbleeds that do not induce cerebral edema formation. This could be something that can be considered as “leaky brain” but their intensity and extend is a far cry of the former word meaning. Thus, the concept of leaky brain is completely fallacious as it is taken out of context and grossly exagerrated.