What is the Blood-Brain Barrier?
The blood-brain barrier (BBB) is a selectively permeable membrane that surrounds the brain and seperates this vital organ from the systemic circulation. The BBB serves the essential function of creating a "protective bubble" around the brain. It can be seen as acting as a gatekeeper - allowing only those molecules from the bloodstream that are required by the brain (e.g. oxygen, hormones) to enter into the brain extracellular fluid, while keeping out substances (neurotoxins) which may be damaging (e.g. metabolic & environmental toxins, bacteria). The BBB also actively transports certain metabolically essential molecules like glucose - that do not cross the barrier passively - into the brain extra cellular fluid via specific protein transporters.
Structure of the Blood-Brain Barrier
The BBB is composed of endothelial cells that are the structural building blocks of blood vessels throughout the body. The difference is that these cells are much more tightly packed in vessels surrounding the brain, forming "tight junctions" - it is these tight junctions between the endothelial cells that form the "barrier". The result is that the blood vessels comprising the BBB restrict passage of molecules from the bloodstream much more than do regular blood vessels elsewhere in the body. Also worthy of note is that the cells of the BBB are heavily supported by specialized cells known as astrocytes found throughout the brain which provide essential nutrients.
What Happens if the Blood-Brain Barrier is Damaged?
Although the BBB is usually an excellent mechanism for protecting the brain from neurotoxins, various factors can cause damage and result in it becoming hyperpermeable, with the result that substances that should be kept away from the brain are able to gain access to the brain extracellular fluid. Some of these factors include:
- Elevations in nitric oxide (NO)1
- Oxidative Stress2
- Psychological Stress3
- Systemic Inflammation/Autoimmune Disease3
- Environmental & Metabolic Toxins4
- Heavy/Toxic Metals5
- Food Additives (e.g. MSG, aspartame)6
- Leaky Gut Syndrome/Intestinal Hyperpermeability7
When the BBB becomes hyperpermeable or dysfunctional due to these and other influences it leaves the brain suspectible to injury from neurotoxins. Such injury can result in symptoms of cognitive dysfunction or mood disorders and may eventually contribute to the development of neurodegenerative disorders such as Alzheimer's disease.8 It is notable to readers of this website that the factors listed are all associated with the development and pathophysiology of environmental illnesses in one way or another so BBB dysfunction/hyperpermeability therefore may theoretically contribute to symptoms in these illnesses and treatment thereof could result in clinical improvement.
Treatments to Heal the Blood-Brain Barrier
If the BBB has been compromised there are a number of ways in which it's structure and function can be restored. Addressing the factors that initially contributed to its dysfunction is vital while additional treatments can support healing directly.
Antioxidant Therapy - Consuming a variety of antioxidants through diet and supplements will help reduce oxidative and nitrosative stress that promote BBB dysfunction. This means including plenty of different fruits and vegetables in your diet and perhaps taking a basic antioxidant complex supplement. If you wish to take things further you may consider Professor Martin Pall's Supplement Protocol which is designed specifically to combat the oxidative and nitrosative stress associated with environmental illness including chronic fatigue syndrome (ME/CFS), fibromyalgia (FM) and multiple chemical sensitivity (MCS). Learn more here.
Avoid Alcohol - Since we know alcohol damages the BBB consumption of alcoholic beverages should be avoided, or your intake at least reduced.
Treat Gut Dysbiosis (where present) - This refers to the presence of yeast and bacteria that would not ordinarily be resident in the gastrointestinal tract, or an overgrowth of species which are normally in balance with beneficial microbial inhabitants. I include this here since yeast produce ethanol (drinking alcohol) as they ferment carbohydrates consumed in the diet - thus damaging the BBB. Yeast also produce the even more damaging acetaldehyde (a chemical cousin of formaldehyde) while an overgrowth of bacteria in the small intestine can cause elevated levels of toxic chemicals including ammonia and hydrogen sulfide in the bloodstream. For more about treating gut dysbiosis see here.
Treat Leaky Gut Syndrome - Tends to go hand in hand with gut dysbiosis and results from damage to the gut lining from microbes, their toxic waste products, stress, nutritional deficiencies and many other factors. Like a hyperpermeable BBB, a hyperpermeable gut lining will allow through molecules that should not normally be able to pass. In this case the molecules (e.g. bacteria, partially digested food particles, large toxins) gain access to the bloodstream. They may then induce allergic and autoimmune reactions and result in chronic inflammation and damage the BBB. Treatment involves addressing gut dysbiosis and optimizing digestion while using nutritional supplements and herbs to heal the gut lining. Learn more here.
Reduce Your Stress Levels - You're probably thinking "easier said than done!" and I can completely understand that. However, there are more ways than one to look at this. If possible it is of course advantageous to reduce the amount of things in your life that cause you stress. Try to delegate tasks you would normally do yourself to others and don't take on more than you can realistically handle. Also, it's worth keeping in mind that stress results from a combination of an event or circumstance and your reaction to these. With this in mind techniques such as meditation, yoga, emotional freedom technique (EFT) and neurolinguistic programming (NLP) can help you react more positively and manage your stress levels more effectively.
Reduce Exposure to Environmental Chemicals - This is difficult in the modern world but if you can create a healthy home and reduce your use of toxic personal care products and cosmetics you are more than halfway there. Toxic chemicals are everywhere in the typical modern home, from laundry detergent, cleaning products, and air fresheners to shampoo, deodorant and perfume/cologne. Learn more about what to avoid and safer alternatives here.
Heavy Metal Removal - Heavy and toxic metals (e.g. aluminum) have unfortunately become ubiquitous in our environment (e.g. electronic goods, personal care products), in dental care (merucury amalgam fillings), and in our food and water supplies. To make matters worse they tend to accumulate in vital organs, including the brain, making their removal problematic. To remove metals from the body they must be chelated (bound) to a non-toxic substance with the metal-chelator complex then being excreted from the body through normal channels. Nutrient and herbal chelators (e.g. alpha lipoic acid, cilantro) are available over-the-counter (OTC) but due to the dangers (redistribution of toxic metals from faty tissue to vital organs) it is wise to seek chelation therapy from a reputable doctor. More on chelation therapy here.
Avoid Food Additives - This is good advice in general because of other potentially harmful effects but avoidance of food additives may aid healing of the BBB. MSG is added to a lot of takeout and prepared foods as well as snacks like chips to give them intense flavor. Aspartame is a sweetener used in diet sodas. For optimal BBB and general health it is best to aim for a natural whole foods diet so that food additives aren't an issue.
Reduce Systemic Inflammation - Important not just for BBB integrity but for every aspect of health. Since syustemic inflammation is caused by all of the other factors we have discussed it should be greatly reduced if these are addressed.
Supplement Thiamine (Vitamin B1) - Deficiency of this vitamin is associated with an increase in nitrosative and oxidative stress and an increase in excitotoxicity (excessive nerve activity) and inflammation - quickly leading to break down of the BBB.9 Supplementing thiamine as part of a B-complex supplement and adding a standalone thiamine supplement in addition (if required) may therefore help support BBB health. Avoid alcohol and tea (and other high phenol & tannin foods/drinks) as these either deplete thiamine or inhibit its absorption from GI tract.
Supplement Phosphatidylcholine (PC) - As mentioned above, the BBB is heavily reliant on cells known as astrocytes. These cells require a lot of energy and have high concentrations of mitochondria; if the mitochondria are damaged or not functioning optimally the BBB will suffer.10 This is where the nutrient phosphatidylcholine (PC) comes in. This fatty substance is the major structural component of cell membranes, and also the membranes surrounding vital intracellular organelles including mitochondria. Increasing PC consumption - available as a nutritional supplement and also found in high concentrations in eggs - may therefore improve mitochondrial functioning within astrocytes and have a positive impact on BBB health as a result.
I am sure this is by no means an exhaustive list of ways in which to support and heal the blood-brain barrier so if you know of others please use the comments form below to let us know...
About: Matthew Hogg ("Maff")
Diagnosed with M.E./chronic fatigue syndrome aged only 11 years old and subsequently associated illnesses including irritable bowel syndrome (IBS) and multiple chemical sensitivity (MCS). Despite his own struggles he has constantly sought to educate and support others suffering from such "invisible illnesses" through his website, The Environmental Illness Resource. He fully recovered from MCS using his own approach and holds a Bachelor of Science Degree in Nutritional Health.
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