What is serotonin?
What do cuddles from your dog and having irritable bowel syndrome have in common?
Both are mediated by a chemical called serotonin.
Although widely regarded as the ‘happy hormone’ in mood regulation, it is in fact a major neurotransmitter that can be found in virtually all major body organ systems such as the heart, lungs, blood vessels, gastrointestinal and reproductive organs (1).
What does serotonin do?
Serotonin modulates nearly all aspects of your behavior – including mood (both reward and feelings of anger), sexuality, perception and appetite (2).
Low levels of serotonin lead to feelings of anxiety, low mood, decreased appetite, insomnia, and low libido (2).
Not coincidentally, these are also symptoms of clinical depression and those who were acutely depleted of serotonin were also found to have increased perception to pain (2).
Your memory is also affected by acute serotonin depletion, specifically impairing the process of converting short-term memories to long-term ones (2).
In depression, patients are often treated with selective serotonin re-uptake inhibitors (SSRIs, example: Prozac) that aim to increase the concentration of active serotonin in the brain. However, these drugs often come with a plethora of uncomfortable side effects.
Are there any ways to safely increase serotonin levels in the healthy individual?
1. Increase intake of dietary tryptophan
Tryptophan, an amino acid, is an essential building block for serotonin (5-hydroxytryptophan).
It should be noted that scientists are at odds over whether tryptophan contained in food really works to raise levels of serotonin. Foods like nuts, seeds, salmon, and eggs are high in tryptophan. However. there is evidence suggesting that tryptophan taken this way does not raise serotonin levels in the body. Reasons for this is that dietary tryptophan isn’t that concentrated, resulting in preferential absorption of other amino acids during the digestive process (4).
Therefore, scientists often use purified tryptophan supplements during studies.
One study comparing participants who took either 5 or 10mg/kg bodyweight per day of dietary tryptophan found that those who took the higher dose reported more positive moods and less anxiety after just four days (3).
In another study, healthy middle-aged women who took 70mg of tryptophan per day in the form of an α-lactalbumin drink for 19 days reported feeling happier and even appeared to be able to have shortened reaction times and sharper focus (5).
2. Get Enough Sunlight
Simply getting enough sunlight may help boost serotonin levels.
Light therapy is the standard treatment for seasonal affective disorder (SAD for short), a form of depression that curiously manifests during the dark winter months (4).
Conventional light therapy involves sitting in front of a box that provides 10,000 lux (measure of light intensity) for half an hour a day.
In comparison, sunlight is about 50,000 lux and a normal office block is about 500. Simply being exposed to 3000 lux for two days significantly improved serotonin levels (7).
Simply put, get some sun.
Running after a stressful day may be a form of release for many – and for good reason.
Exercise has shown to be a proven method of increasing serotonin levels, with individuals who jogged just 30 minutes a day for a few months experiencing higher remission rates than those who took anti-depressants alone (8).
Exercise increases the rate of serotonin synthesis, an effect that may persist even after exercise (2).
4. Human Touch
Last but not least, mere human touch is able to decrease stress levels and increase both serotonin and dopamine. Massage therapy is greatly beneficial alleviating the stress encountered in pain syndrome, HIV, breast cancer, occupational and pregnancy stress (9). More intimate touch such as cuddling and hand holding also fires up oxytocin levels – the ‘social hormone’ – that promotes bonding and feelings of trust (10).
While it may seem trivial, your mood is a powerful predictor of health.
Hostile feelings were found to be an independent risk factor for developing coronary heart disease (11).
A classic study of Catholic nuns found that those who experienced more positive emotions in their 20’s lived 10 years longer than those who were extremely negative (12).
So stay positive and find way to optimize and improve your mood, cognition, and mental performance. Will all this we can help. Sign up below with your e-mail to receive tips, tricks, and hacks to improving your brain health, mood, and cognitive and mental performance.
1. Berger M., Gray J.A., Roth B.L.. The expanded biology of serotonin. Annu. Rev. Med. 2009. 60:355–66.
2. Jenkins T.A., Nguyen J.C.D., Polglaze K.E., Bertrand P.P.. Influence of Tryptophan and Serotonin on Mood and Cognition with a Possible Role of the Gut-Brain Axis. Nutrients. 2016;8(1):56. doi:10.3390/nu8010056.
3. Lindseth G., Helland B., Caspers J. The Effects of Dietary Tryptophan on Affective Disorders. Archives of psychiatric nursing. 2015;29(2):102-107. doi:10.1016/j.apnu.2014.11.008.
4.Young S.N. How to increase serotonin in the human brain without drugs. Journal of Psychiatry & Neuroscience: JPN. 2007;32(6):394-399.
5. Mohajeri M.H., Wittwer J., Vargas K., Hogan E., Holmes A., Rogers P.J., et al. Chronic treatment with a tryptophan-rich protein hydrolysate improves emotional processing, mental energy levels and reaction time in middle-aged women. British Journal of Nutrition. Cambridge University Press; 2015;113(2):350–65.
6. Perreau-Linck E., Beauregard M., Gravel P., Paquette V., Soucy J.P., Diksic M., Benkelfat C. In vivo measurements of brain trapping of C-labelled alpha-methyl-L-tryptophan during acute changes in mood states. J Psychiatry Neurosci. 2007 Nov; 32(6):430-4.
7. aan het Rot M., Benkelfat C, Boivin D.B., Young S.N .Bright light exposure during acute tryptophan depletion prevents a lowering of mood in mildly seasonal women. European Neuropsychopharmacology. 2008;18(1):14-23
8. Blumenthal J.A., Babyak M.A., Murali Doraiswamy P, et al. Exercise and Pharmacotherapy in the Treatment of Major Depressive Disorder. Psychosomatic medicine. 2007;69(7):587-596. doi:10.1097/PSY.0b013e318148c19a.
9. Field T, Hernandez-Reif M, Diego M, Schanberg S, Kuhn C. Cortisol decreases and serotonin and dopamine increase following massage therapy. Int J Neurosci. 2005 Oct;115(10):1397-413.
10. Coan J. A., Schaefer H.S., Davidson R.J. Lending a Hand: Social Regulation of the Neural Response to Threat. Psychological Science. 2006;17(12):1032-1039. https://doi.org/10.1111/j.1467-9280.2006.01832.x
11. Miller, T. Q., Smith, T. W., Turner, C. W., Guijarro, M. L., & Hallet, A. J. (1996). Meta-analytic review of research on hostility and physical health. Psychological Bulletin. 1996;19(2):322-348. http://dx.doi.org/10.1037/0033-2909.119.2.322
12. Danner, D. D., Snowdon, D. A., & Friesen, W. V.. Positive emotions in early life and longevity: Findings from the nun study. Journal of Personality and Social Psychology. 2001:80(5);804-813. http://dx.doi.org/10.1037/0022-3522.214.171.1244