Lyme and the Blood Brain Barrier
The blood-brain barrier (BBB) is what is often damaged in Lyme patients needing brain therapy. The truth is, everyone probably has some damage to their BBB. In attempting to help heal it, I think that we need to understand some vascular biology.
How does BBB damage begin?
It starts in the vessels, both cranial and systemic. Just like heart disease, brain inflammation begins as an endothelial problem. The endothelium is the lining of the arteries and since we are talking about the blood-brain barrier, we’ll discuss the vessels that feed the brain. Remember, neuronal function is dependent on both fuel and activation and the fuel is delivered through the arteriole system guarded closely in the brain by the special glial cells called astrocytes.
The endothelium is a single layer of cells that act as a wall with thousands of little gates called receptors that allow certain chemicals in to affect the smooth muscle layer beneath it. If this protective wall gets damaged or the gates get stuck open, we are going to have a problem and a problem in the vessel wall soon spells a problem in the barrier.
Blood testing that should always be considered (and seldom is) with all brain-based symptoms includes a complete vascular profile but measuring cholesterol, HDL and LDL is insufficient in testing out vessel health. All HDL isn’t “good” and all LDL isn’t “bad.” Ask your doctor for more specific tests like hsCRP, Homocysteine, oxidizedLDL, Lipoprotein A, and Apolipoproteine A.
Your vessels are lined with a single-cell layer of tissue called endothelium; under this endothelial layer is a smooth muscle layer that is responsible for contracting (raising blood pressure in times of needed blood flow) and relaxation (lowering and normalizing arterial pressure in the brain). This endothelial lining is really the KEY; it is the barrier, the wall that allows both willingly and not, changes in the muscle tone as well as invasions into the delicate space underneath.
Our Barriers ARE our Protection
Let’s say this again but start at the beginning. We eat food and impurities hit the first barrier, the stomach. Here, the pH is extremely acidic for two main reasons: it digests (breaking for into smaller particles) and kills pathogens. This second purpose of HCl (stomach acid) is of vital importance as it is the first line of defense against potential destroyers of other barriers like the blood-brain barrier. Helicobacter pylori, for example, are ubiquitous bacteria that should be easily killed by a normal acid balance in the stomach. If you have an imbalanced HCl supply, H. pylori infiltrates and can either cause a stomach or duodenal ulcer or will pass through attacking other organs. It is estimated that 95% of H. pylori infections are chronic, insidious and subclinical – meaning it is rarely diagnosed as a disorder itself and usually the culprit of many other named diseases. H. pylori is such a common cause of vessel damage that leads to both heart disease and blood-brain barrier disruption that I’ve devoted an entire section on it later in this book.
The second barrier an ingested item encounters is the intestinal wall. Here, cells lining the hair-like villi protect unwanted guests from entering. Proteins, for example, are broken into individual amino acids that are small enough to traverse the cellular barricade. Much of the problem with food sensitivities comes in when separation of the intestinal cells allows food proteins to pass into the blood before they are completely digested into amino acids. These proteins and protein particles called peptides are foreign to the body, stimulate an immune response and our body makes antibodies against them. This is how gluten becomes an autoimmune antigen and wreaks havoc through the body. Again, it all starts with a broken barrier.
The next barrier needing to be crossed is the intimal lining of the blood vessel. Blood flows through the lumen of the vessels and interacts with receptors in the inner covering called intimal endothelial cells. These are barrier cells that allow nutrients to pass to feed cells. All cardiovascular disease as well as every brain disorder discussed in this book starts with endothelial disease! Again, think of the endothelial cell layer as a fence with hundreds of gates called receptors. These gates are opened with specific chemical keys that change the function of the smooth muscle layer behind the fence and can even change the shape of the fence itself. Under normal conditions, chemicals released by tissues knock on the gates looking for permission to enter. For instance, a sympathetic nervous system response (fight or flight) in the brain to a perceived stress causes the release of a chemical that will enter a gate in the endothelial fence to cause the smooth muscle layer to contract and narrow the lumen of the vessel. This increases the speed of blood flow and increases the blood pressure so you can run away from the danger. It is a normal response, but like any normal response, we can get ‘stuck’ in an ‘on’ position from chronic source of stimulation.
There are really an endless number of possible insults that could ‘breach the gates’ of the endothelial wall. Chemical toxicity, heavy metal toxicity, food additives, flavorings, colorings, infections, and endotoxins are just a few of the things that can break the gates and cause damage to the endothelial layer, the small, smooth muscles and tissue underneath, and interact with the astrocytes that act as the next (and special) barrier in the brain. You may have heard about the damage that Homocysteine, glucose, or oxidized LDL cause, but by far, the worst culprit for damage is infection.
Subclinical (silent) infections are the number one ‘bad guy’ causing endothelial disease which leads to blood-brain barrier disruption. “Subclinical” means the patient doesn’t know they have it! It’s a silent disorder that can cause mild, insidious vasculature damage for years (and yes, it can start at birth) until the victim has symptoms of ADHD, anxiety, depression, memory loss and dementia, just to name a few. I know this is a lot of info so I’ll sum this up:
- BBB disruption really starts with damage to the endothelial layer – the single-celled barrier that lines the vessels.
- If the endothelial layer is ‘breached’, several bad things occur that lead to inflammation in the vessel wall, the tiny muscles underneath the wall, and the astrocyte cells that are meant to keep larger molecules of things out of the CNS
- Many possible sources of endothelial damage exist due to poor diet, environmental exposure to toxins, and ubiquitous infectious organisms but subclinical infections (unknown to the patient) are the most common and least diagnosed cause of endothelial disease and hence, brain disorders.
Endothelial disease is always the start of BBB disruption and usually never addressed by the any doctor. Heck, most doctors don’t even address the fact that there is a disruption in the BBB. Worse, many doctors are still blaming the patient’s depression on a chemical imbalance as if it was a disease that poor victim contracted when they were caught out in the rain without a jacket. Medications can change a person’s mood, they can numb symptoms, and dull hyperactivity. Medications cannot cure because they do nothing for ‘cause’.