Serotonin is a neurotransmitter that is responsible for your happiness! Most anti-depressants focus on the production of serotonin. To improve your mood and happiness you can discover tons of our favorite biohacks in our ebook, SelfHacked Secrets. Download the first chapter here for free.
What is Serotonin?
Serotonin, also called 5-Hydroxytryptamine (5-HT), is a biochemical messenger and regulator, synthesized from the essential amino acid L-Tryptophan.
In humans, it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets.
It mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity (R).
Beneficial Effects of Serotonin
1) Serotonin 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 (R).
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 (R).
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 (R).
2) Serotonin 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 (R).
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 (R).
3) Serotonin 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 (R).
One study in rats (Tph2 knockout) suggests that 5-HTP is important to balance the control systems for breathing and temperature during development (R).
Neurons in all of the nuclei that govern respiratory control have serotonin neurons (R).
4) Brain Serotonin Can Affect Your Mood
Acute tryptophan depletion (ATD) can result in lower mood and 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 (R).
5) Serotonin 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) (R).
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 (R).
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.
It can also indirectly contribute to vasoconstriction by amplifying the response of other vasoactive substances such as NET, angiotensin II, and histamine (R).
6) Serotonin May Impact Bone Regulation
5-HT receptors have been identified in all the major bone cell types (osteoblasts, osteocytes, and osteoclasts) (R).
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 (R).
Some studies suggest a direct stimulatory effect of 5-HT on bone formation pathways (R), whereas others have found inhibitory effects (R).
7) Serotonin 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 (R).
Several mechanisms were proposed to explain this including direct vasodilation, inhibition of adrenergic input, and stimulation of central areas contributing to correction of vasomotor tone.
5-hydroxytryptamine causes heart and lung tissue to replicate and grow (R, R, R).
In mice and people, high levels of 5-HT2B in the lungs are associated with the development of pulmonary hypertension (R, R).
8) Serotonin 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 (R).
9) Serotonin Impacts Anorexia Nervosa
5-HTP is involved in almost all the behavioral changes observed in Anorexic patients.
Both genetic and environmental factors contribute toward anorexia. It is suggested that tryptophan supplementation may help anorexics (R).
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) Serotonin 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 (R).
There is clear evidence that dopamine and 5-Hydroxytryptamine neuronal systems interact in ADHD (R).
11) Serotonin 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:
Carbohydrate consumption–acting via insulin secretion and the “plasma tryptophan ratio”–increases serotonin release; protein intake lacks this effect (R).
12) Serotonin 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 (R).
Ways to Naturally Increase Serotonin
SSRIs increase serotonin levels in the brain and are safer than other antidepressants [R].
However, SSRIs still have many side effects. It can cause discontinuation syndrome, sexual dysfunction, nausea, skin reactions, weight gain, and sleep disturbances [R].
In rats, long-term SSRI use aggravated serotonin deficiency [R].
Thus, it is crucial that we find other alternatives to drugs that can increase serotonin levels.
Making lifestyle changes can prevent depression, anxiety, and related disorders before they start. Below, we highlight a few natural ways to boost serotonin levels for mental and physical well-being.
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 [R].
Positive thoughts have a positive impact on one’s self-esteem and mood. On the other hand, over-thinking based on inaccurate beliefs has a causal role in depression [R].
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 [R].
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 [R].
Aerobic exercise is scientifically proven to improve serotonin levels in the brain. In a study of 16 seniors, the long-term aerobic training helped increase serotonin activity [R, R].
In rats, short-term exercise also increased serotonin activity [R].
Additionally, exposure to bright sunlight naturally boosts serotonin. Therefore, exercising outdoors can increase serotonin levels and improve mood [R].
3) Listening to Pleasant Music
Listening to music with a positive vibe and lyrics based on positive emotions can improve mood [R].
In a study of 20 healthy subjects, listening to pleasant music increased their serotonin levels. Meanwhile, serotonin levels decreased when listening to unpleasant music [R].
4) Social Interactions
Social interaction and perceived facial expression have a strong correlation with serotonin levels [R].
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 [R].
5) Sleeping Right
Having a normal sleep schedule is important for serotonin balance. During sleep, the brain releases serotonin [R].
Sleep deprivation can desensitize serotonin receptors. This can cause problems with serotonin and increase the likelihood of depression [R].
Partaking in fun activities such as nature walks, meditation and massages all have a positive effect on serotonin levels [R, R, R].
Although bananas, plums, etc. contain serotonin, eating these foods will not increase our brain’s serotonin levels [R].
Consuming foods that contain tryptophan, an amino acid required for serotonin production, will also not boost serotonin levels in our brain [R].
1) Omega-3 Fatty Acids
Omega-3 fatty acids, such as EPA and DHA, increase serotonin levels [R].
Increasing omega-3 fatty acids through supplementation can increase serotonin release by the neurons to our brain, thereby keeping our minds sharp [R].
Foods rich in EPA and DHA include [R]:
Fatty fish (salmon and sardines)
2) Vitamin D
In the brain, serotonin synthesis, from tryptophan, needs Vitamin D. Vitamin D deficiency can contribute to dysfunctional serotonin activation and cause brain problems [R].
Vitamin D food sources include [R]:
Fish and shellfish
Milk also contains a protein called alpha-lactalbumin. It can increase tryptophan levels, and possibly serotonin [R].
We crave for carbs or sweets when we are sad. This is because carbohydrate intake increases serotonin levels in our body by secreting insulin [R].
Small amounts of carbohydrates can also increase tryptophan availability by letting it cross the blood-brain barrier to be turned into serotonin [R].
In rats, St. John’s Wort supplementation increased serotonin formation by inhibiting the TDO enzyme [R].
Curcumin also helps enhance serotonin release. In rats, curcumin treatment had an anti-depression effect and increased serotonin and dopamine release [R, R].
Caution should be taken when including herbs in your diet. Overdose leads to possible side effects [R].
Various agents can inhibit 5-HT reuptake, including cocaine, dextromethorphan (an antitussive), tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs).
In animals including humans, 5-Hydroxytryptamine is synthesized from the amino acid L-tryptophan by a short metabolic pathway consisting of two enzymes: tryptophan hydroxylase and aromatic amino acid decarboxylase [R].
The essential amino acid tryptophan hydroxylates to 5-hydroxytryptophan (5-HTP) by tryptophan hydroxylase. In a second step, 5-HTP is decarboxylated to form 5-HT [R].
Definitely NOT understanding the first paragraph about affecting heart function-- a good thing or a bad thing.....??