How does it work?
Our whole body is criss-crossed by blood vessels, through which the blood vessels supply our organs and tissues with important nutrients and oxygen - including the central nervous system (CNS for short), which consists of the brain and spinal cord. This is where the blood-brain barrier is located, which is a kind of filter that only lets certain molecules in and out of the CNS.
How is it structured?
On the inside of the vessel walls of the capillaries are the vessel wall cells (endothelial cells), which in turn are tightly bound together by narrow, belt-shaped junctions (tight junctions). Together with the basement membrane and the astrocytes, which coat the vessels from the CNS side, they form the blood-brain barrier.
What is it good for?
The blood-brain barrier selectively decides which molecules, cells or ions are transported from the blood into the CNS and which waste products are excreted again. This filter function is intended to protect our brain from toxic substances, which are then not allowed to pass through. The selection often works, but also has a few weaknesses: Alcohol or nicotine, for example, can easily get through the barrier.
Who is allowed in, who has to stay outside?
According to a rule of thumb, substances that are small and lipophilic, i.e. fat-loving, are transported into the brain, while large molecules that are hydrophilic, i.e. water-loving, tend not to be let through. Of course, there are always exceptions to the rule.
How does this affect my everyday life?
Have you ever wondered how an active ingredient knows where to work? How does an active ingredient know, for example during a period, that it should work in the abdominal area and not in the head? The answer actually lies in the blood-brain barrier, because through non-selection it ensures that the active substance Buscopan does not develop its effect in the brain and we may become dizzy or tired, but instead it has its effects specifically in the abdomen .
The example of serotonin / 5-HTP
But the other way around, substances that are needed there do not get directly into the brain. Serotonin is an exciting example here. Also known as the "happiness hormone", it is one of the most important amines that acts as a neurotransmitter that transmits information between nerve cells. The ability to influence our emotions and psyche gives it its nickname. One would think that such a necessary and natural hormone should be able to get to the brain without any problems, but it isn't. To bypass the barrier, the body uses two precursors of serotonin: tryptophan, which occurs naturally in African black beans, bananas or chocolate, and 5-HTP. Tryptophan is converted by the body into the intermediate 5-HTP and then further into serotonin. While serotonin, as previously mentioned, cannot cross the blood-brain barrier, the precursors tryptophan and 5-HTP can both easily cross it and then be further converted to serotonin in the brain. 5-HTP has therefore been actively used for over 30 years as a therapeutic agent against depression, anxiety, panic, sleep disorders, eating disorders, PMS or chronic headaches.
We at mybacs have also dealt with this topic and developed our add-on “Good Mood” in the course of this. High-quality 5-HTP, ashwagandha, saffron extract and other valuable vitamins ensure a real mood boost and support your general well-being.
Sources
https://pubmed.ncbi.nlm.nih.gov/25561720/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7796270/
https://www.hormonzentrum-an-der-oper.de/files/content/Broschueren/Hormonzentrum/5HTP-Hormonzentrum-an-der-Oper.pdf
