Serotonin is a neurotransmitter that most commonly associated with its mood-regulating role in the brain. However, most serotonin is found outside of the central nervous system, and serotonin receptors are expressed throughout the body, including the brain. Read on to learn more about all the roles that serotonin plays in your body and about natural ways you can increase your serotonin levels.
What is Serotonin?
Serotonin, also called 5-Hydroxytryptamine (5–HT), belongs to the family of neurotransmitters called catecholamines and acts as a biochemical messenger and regulator. It is synthesized from the essential amino acid l-tryptophan by the enzyme tryptophan hydroxylase.
In humans, it is found primarily in the central nervous system (CNS), gastrointestinal tract, and blood platelets.
It mediates many important physiological functions both within and outside the CNS including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity .
Beneficial Effects of Serotonin
1) Affects Heart Function
5-Hydroxytryptamine can be considered as a significant circulating hormonal factor implicated in normal cardiovascular function either by acting directly on heart cells or by stimulating chemosensitive nerves from the heart .
Patients with carcinoid tumors (rare slow-growing cancers) have high levels of this regulator associated with arrhythmia, leading to heart block or to valvular fibroplasia .
Also, mouse embryos grown in the presence of either a high concentration of 5-Hydroxytryptamine or Serotonin-specific reuptake inhibitors show a decreased proliferation of myocardium, cardiac mesenchyme, and endothelium .
2) Induces Intestinal Secretions
In the gastrointestinal tract, 5-HT initiates responses like nausea, intestinal secretion, and peristalsis and has been implicated in gastroenteric diseases like irritable bowel syndrome .
The secretory effects of 5-HT are mediated through different receptors: It induces secretion across human ileal mucosa, whereas a receptor of the 5-HT2A subtype appears to mediate the effect in the human sigmoid colon .
3) Helps Control Body Temperature and Breathing
5-HT-producing cells in the mouse brain play an essential role in maintaining a healthy balance in body temperature and breathing .
Neurons in all of the nuclei that govern respiratory control have serotonin neurons .
4) Brain Serotonin Can Affect Your Mood
Acute tryptophan depletion (ATD) can result in a lower mood and an increase in irritability or aggressive responding.
Overall, studies manipulating tryptophan levels support the idea that low 5-Hydroxytryptamine levels can predispose subjects to mood and impulse control disorders.
Higher levels of 5-HT may help to promote more constructive social interactions by decreasing aggression and increasing dominance .
5) Contracts Vascular Muscles
5-HT causes contraction of the vascular smooth muscle cells in most blood vessels studied in the lab (mainly due to the activation of S2-serotogenic receptors) .
The original intent of investigating 5-HT was for its vasoconstrictor effects. Early studies in dogs established a triphasic response to serotonin when injected intravenously .
- An initial fall in blood pressure
- A rise in blood pressure
- Another fall in blood pressure
When released from activated platelets, 5-HT can induce vasoconstriction in most large arteries, large veins, and venules.
6) May Impact Bone Regulation
5-HT receptors have been identified in all the major bone cell types (osteoblasts, osteocytes, and osteoclasts) .
Recent data suggest that gut-derived 5-Hydroxytryptamine may mediate the skeletal effects of LDL receptor-related protein 5.
Evidence suggests that SSRIs (Selective Serotonin Reuptake Inhibitors) are associated with reduced bone mass, increased bone loss, and increased risk of fractures .
7) Increases Hypertension
Early experiments with specific 5-HT receptor antagonists indicated that 5-HT1-like antagonism, as well as serotonin antagonism, corrected hypertension in animal models .
Several mechanisms were proposed to explain this including direct vasodilation, inhibition of adrenergic input, and stimulation of central areas contributing to the correction of vasomotor tone.
8) Affects Depression
Alterations in the serotogenic neuronal function in the central nervous system occur in patients with major depression, which can be evidenced by the reduced concentration of 5-HT in the postmortem brain tissue of the depressed.
In a pilot study in patients with major depression, alterations in 5-HT neurons showed to play a role in the cause of depression .
9) Impacts Anorexia Nervosa
5-HTP is involved in almost all the behavioral changes observed in Anorexic patients.
Both genetic and environmental factors contribute to anorexia. It is suggested that tryptophan supplementation may help anorexics .
Tryptophan is a precursor of serotonin and an essential amino acid only available in the diet, it is, therefore, likely that excessive diet restriction may lead to decreased brain 5-HT stores.
10) Impacts Attention-Deficit Hyperactivity Disorder
In one controlled trial, families were studied to determine the link between the serotogenic system and Attention-Deficit Hyperactivity Disorder (ADHD). Preliminary data suggested an important role of the 5-HT system in the development of ADHD .
11) Affects Carbohydrate-Craving And Obesity
5-HT-releasing brain neurons are unique in that the amount of neurotransmitter they release is normally controlled by food intake:
12) May Play A Role In Kidney Activity
In kidney injury, tissue damage occurs and platelet activation is observed. Recent studies suggest that some factors, such as 5-Hydroxytryptamine, are released into microenvironment upon platelet activation following kidney injury .
Ways to Naturally Increase Serotonin
SSRIs increase serotonin levels in the brain and are safer than other antidepressants .
Thus, it is crucial that we find other alternatives to drugs that can increase serotonin levels.
1) Positive Thinking
Just as low serotonin levels negatively affect our mood, negative moods also cause serotonin levels to drop. This triggers a range of physical and mental health issues. Inducing positive moods by mental exercises is a good start to maintaining healthy serotonin levels .
Cognitive therapy is a safe and efficient treatment for depression. It requires one to identify thoughts that trigger negative emotions, distance themselves from those thoughts, and to question the validity of their beliefs through experiments .
Employing such an objective thought process in day-to-day life could be a natural way to keep depression at bay and raise serotonin levels .
In rats, short-term exercise also increased serotonin activity .
3) Listening to Pleasant Music
In a study of 20 healthy subjects, listening to pleasant music increased their serotonin levels. Meanwhile, serotonin levels decreased when listening to unpleasant music .
4) Social Interactions
Social interaction and perceived facial expression have a strong correlation with serotonin levels .
Interactions with individuals exhibiting negative traits or emotional states, such as aggressive behavior, causes you to mirror their emotional states. However, the same holds true for positive emotional states .
5) Good Sleeping Habits
Having a normal sleep schedule is important for serotonin balance. During sleep, the brain releases serotonin .
Sleep deprivation can desensitize serotonin receptors. This can cause problems with serotonin and increase the likelihood of depression .
6) Pleasant Experiences
Dietary/Nutritional & Supplementation Methods
Although bananas, plums, etc. contain serotonin, eating these foods will not increase our brain’s serotonin levels .
Consuming foods that contain tryptophan, an amino acid required for serotonin production, will also not boost serotonin levels in our brain .
1) Omega-3 Fatty Acids
Increasing omega-3 fatty acids through supplementation can increase serotonin released by the neurons in our brain, thereby keeping our minds sharp .
- Fatty fish (salmon and sardines)
2) Vitamin D
Vitamin D food sources include :
- Fish and shellfish
Milk also contains a protein called alpha-lactalbumin. It can increase tryptophan levels, and possibly serotonin .
Small amounts of carbohydrates can also increase tryptophan availability by letting it cross the blood-brain barrier to be turned into serotonin .
In rats, St. John’s Wort supplementation increased serotonin formation by inhibiting the TDO enzyme .
Want More Targeted Ways to Improve Your Mood?
If you’re interested in natural and more targeted ways of improving your mood, we at SelfHacked recommend checking out this mood wellness report. It gives genetic-based diet, lifestyle and supplement tips that can help improve your mood. The recommendations are personalized based on your genes.
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