Link Between Sleep Apnea & Serotonin (5-HTP)
Serotonin (5-Hydroxytryptamin (5-HTP) or Enteramin) is a neurotransmitter that is primarily found in the central nervous system, the gastrointestinal tract and the blood. Primarily it is known to impact the feeling of well being. Sometimes it is even called the “happiness hormone”. Interestingly about 95% of it is usually located in the the gut of which 90% are in the enterochromaffin cells where it is produced and regulates the intestinal movements. Most of the remainder is located in serotonergic neurons in the central nervous system and in the blood. In addition to it’s function in the gastrointestinal tract it also supports signal transmission in the nervous system and the tone of blood vessels.
How does serotonin influence sleep apnea?
The main impact of serotonin is on the gastrointestinal tract, the nervous system and the cardiovascular system.
1. Effects on the cardiovascular system
Serotonin is the regulator of relaxation, contraction and overall tone of muscles around the blood vessels. For the kidney and lung the more important part is the contraction, while in the blood vessels themselves the relaxation plays the bigger role. It’s a given that a malfunction in the cardiovascular system can cause disruptions that lead to sleep apnea. Sleep apnea will likely be influenced by changes in the serotonin levels in the blood.
2. How the central nervous system is influenced:
The best known effect of serotonin on the body is it’s influence on moods through the central nervous system. At a serotonin level in the brain, that is too high, hallucinations and restlessness can be caused. Meanwhile depressions are often traced to low levels. In some cases anxiety and bad aggressive temper can be traced back to low levels of serotonin.
BUT: Banana and Chocolate do not actually help by adding serotonin. The uplifting effect is due to the high level of carbohydrates that lead to an increase in the production of neurotransmitters in the brain.
b. Sleep-Wake Cycle
The strong influence of serotonin on the sleep-wake cycle is known since the 1950′s. But the older studies have been contradictory when it came to the mechanisms behind that. More recently, studies have shown that the activity of serotonin containing neurons in the hypothalamus regulate the wake periods. During sleep this activity is reduced and almost stops during REM. Any change in the serotonin level will likely cause disruptions in the sleep-wake cycle and likely have an affect on the exposure to sleep apnea.
A certain serotonin level is needed in the nerves that control breathing in order to receive information from the brain. An improperly-working serotonin system deprives the body of an adequate supply of the neurotransmitter, often resulting in sleep apnea. In addition the release of hormones like cortisol is controlled by serotonin receptors. Among other things cortisol supports the control of the muscles needed for breathing.
Cases of sleep apnea that are based on a low serotonin level can be successfully treated with 5-HTP as part of the patient’s medication (Dr. Murray in “5 HTP – The Natural Way to Overcome Depression, Obesity, and Insomnia”).
He recommends a dose of 100 to 300 mg of 5-HTP before going to bed. Dr. Murray reports that sleep apnea patients that take 5-HTP sleep more soundly and wake up less.
Although this is great new, 5-HTP alone will not cure sleep apnea. In every case it should be part of a strategy that also targets obesity, breathing habits, lifestyle (alcohol/nicotine/narcotics) and so on. Consult your Doctor about the use of 5-HTP and other medication as well as interactions of the medicine you use.