Tryptophan is the precursor to the “happiness hormone” serotonin, so why not take tryptophan supplements to improve mood and relieve symptoms of depression?
The Wrong Way to Boost Serotonin
Recent studies like this suggest that dietary patterns characterized by high intakes of vegetables, fruit, mushrooms and soy products are associated with fewer depressive symptoms.
The year before, it was this study, “The association between dietary patterns and mental health in early adolescence,” showing “[i]mproved behavioural scores…significantly associated with higher intakes of leafy green vegetables and fresh fruit.
Could any of this be because of the psychoactive substances found in plant foods?
The neurotransmitter serotonin, often referred to as the “happiness hormone,” is found in plant foods. But, serotonin doesn’t cross the blood-brain barrier. So, it shouldn’t affect our mood, no matter how much we eat.
The precursor to serotonin, however, what your body makes serotonin out of, is an amino acid called tryptophan. And, there’s a transport protein in the brain that plucks tryptophan out of the bloodstream, and so, what you eat can end up affecting your mood.
Back in the 70s, they did tryptophan depletion experiments, where you give people specially concocted tryptophan-deficient diets. And, indeed, their mood suffers. They get irritable, annoyed, angry, depressed, right? Their body just can’t make enough serotonin.
Likewise, you can give people tryptophan pills to improve their mood. And, indeed, it became a popular dietary supplement—until people started dying from something called eosinophilia myalgia syndrome, an incurable, debilitating, and sometimes fatal flu-like neurological condition, caused by the ingestion of tryptophan supplements.
May have been due to some unknown impurity, but, better safe than sorry. Instead of supplements, there are dietary strategies one can use to improve mood—which we’ll talk about next.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Kerry Skinner.
Please consider volunteering to help out on the site.
- Ghirri A, Cannella C, Bignetti E. The psychoactive effects of aromatic amino acids. Current Nutrition & Food Science. 2011 February;7(1):21-32.
- Ly D, Kang K, Choi JY, Ishihara A, Back K, Lee SG. HPLC analysis of serotonin, tryptamine, tyramine, and the hydroxycinnamic acid amides of serotonin and tyramine in food vegetables. J Med Food. 2008 Jun;11(2):385-9.
- Allen JA, Peterson A, Sufit R, Hinchcliff ME, Mahoney JM, Wood TA, Miller FW, Whitfield ML, Varga J. Post-epidemic eosinophilia-myalgia syndrome associated with L-tryptophan. Arthritis Rheum. 2011 Nov;63(11):3633-9.
- Oddy WH, Robinson M, Ambrosini GL, O'Sullivan TA, de Klerk NH, Beilin LJ, Silburn SR, Zubrick SR, Stanley FJ. The association between dietary patterns and mental health in early adolescence. Prev Med. 2009 Aug;49(1):39-44.
- Nanri A, Kimura Y, Matsushita Y, Ohta M, Sato M, Mishima N, Sasaki S, Mizoue T. Dietary patterns and depressive symptoms among Japanese men and women. Eur J Clin Nutr. 2010 Aug;64(8):832-9.
- Odjakova M, Hadjiivanova C. Animal neurotransmitter substances in plants. Bulg J Plant Physiol. 1997;23:94–102.
Images thanks to Esquilo, Jynto, and Neutrality via Wikimedia Commons
Recent studies like this suggest that dietary patterns characterized by high intakes of vegetables, fruit, mushrooms and soy products are associated with fewer depressive symptoms.
The year before, it was this study, “The association between dietary patterns and mental health in early adolescence,” showing “[i]mproved behavioural scores…significantly associated with higher intakes of leafy green vegetables and fresh fruit.
Could any of this be because of the psychoactive substances found in plant foods?
The neurotransmitter serotonin, often referred to as the “happiness hormone,” is found in plant foods. But, serotonin doesn’t cross the blood-brain barrier. So, it shouldn’t affect our mood, no matter how much we eat.
The precursor to serotonin, however, what your body makes serotonin out of, is an amino acid called tryptophan. And, there’s a transport protein in the brain that plucks tryptophan out of the bloodstream, and so, what you eat can end up affecting your mood.
Back in the 70s, they did tryptophan depletion experiments, where you give people specially concocted tryptophan-deficient diets. And, indeed, their mood suffers. They get irritable, annoyed, angry, depressed, right? Their body just can’t make enough serotonin.
Likewise, you can give people tryptophan pills to improve their mood. And, indeed, it became a popular dietary supplement—until people started dying from something called eosinophilia myalgia syndrome, an incurable, debilitating, and sometimes fatal flu-like neurological condition, caused by the ingestion of tryptophan supplements.
May have been due to some unknown impurity, but, better safe than sorry. Instead of supplements, there are dietary strategies one can use to improve mood—which we’ll talk about next.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Kerry Skinner.
Please consider volunteering to help out on the site.
- Ghirri A, Cannella C, Bignetti E. The psychoactive effects of aromatic amino acids. Current Nutrition & Food Science. 2011 February;7(1):21-32.
- Ly D, Kang K, Choi JY, Ishihara A, Back K, Lee SG. HPLC analysis of serotonin, tryptamine, tyramine, and the hydroxycinnamic acid amides of serotonin and tyramine in food vegetables. J Med Food. 2008 Jun;11(2):385-9.
- Allen JA, Peterson A, Sufit R, Hinchcliff ME, Mahoney JM, Wood TA, Miller FW, Whitfield ML, Varga J. Post-epidemic eosinophilia-myalgia syndrome associated with L-tryptophan. Arthritis Rheum. 2011 Nov;63(11):3633-9.
- Oddy WH, Robinson M, Ambrosini GL, O'Sullivan TA, de Klerk NH, Beilin LJ, Silburn SR, Zubrick SR, Stanley FJ. The association between dietary patterns and mental health in early adolescence. Prev Med. 2009 Aug;49(1):39-44.
- Nanri A, Kimura Y, Matsushita Y, Ohta M, Sato M, Mishima N, Sasaki S, Mizoue T. Dietary patterns and depressive symptoms among Japanese men and women. Eur J Clin Nutr. 2010 Aug;64(8):832-9.
- Odjakova M, Hadjiivanova C. Animal neurotransmitter substances in plants. Bulg J Plant Physiol. 1997;23:94–102.
Images thanks to Esquilo, Jynto, and Neutrality via Wikimedia Commons
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The Wrong Way to Boost Serotonin
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Content URLDoctor's Note
This is the second of a four-part series (mentioned in Uprooting the Leading Causes of Death) on natural ways to boost serotonin in the brain. Yesterday’s video-of-the-day Human Neurotransmitters in Plants noted that plants themselves can contain serotonin. Tomorrow’s video-of-the-day A Better Way to Boost Serotonin will talk about getting dietary tryptophan into the brain, which we’ll then optimize in The Best Way to Boost Serotonin. Avoidance of soda and artificial colors (see Are Artificial Colors Bad for You?) may also improve behavior in children and adolescents. Also, check out my other videos on supplements–the good (see Safest Source of B12); the bad; the ugly (see Update on Herbalife®); and the just plain snake oil (see Dietary Supplement Snake Oil). Unfortunately, too many people rely on the questionable advice from health food store employees (see my four-part video series that begins with Health Food Store Supplement Advice).
For more context, check out my associated blog posts: How To Boost Serotonin Naturally; Top 10 Most Popular Videos of the Year; Saffron vs. Prozac for Depression; and Treating Parkinson’s Disease with Diet.
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