A September 2002 review published in "American Family Physician" reported that depression is the second most common chronic disorder seen by primary care physicians, and at least 10 percent of depressed individuals suffer from major depression. Management of major depression usually requires the use of antidepressant medications that modify levels of neurotransmitters, such as serotonin, in your brain. People with milder depression sometimes seek to modify neurotransmitter levels with foods or supplements, although such approaches have not been proven effective.
Neurotransmitters and Moods
Neurotransmitters are simply chemical messengers that propagate electrical impulses across the microscopic gaps, called synapses, which separate your nerves. If neurotransmitters are not produced in sufficient amounts, or if they are not metabolized appropriately, your nervous system cannot function optimally. According to "The Merck Manual of Diagnosis and Therapy," neurotransmitter abnormalities that occur in the mood-controlling centers of your brain can result in depression.
Serotonin from L-Tryptophan
Serotonin is among the most important mood-stabilizing neurotransmitters. It is synthesized in your brain from the essential amino acid, L-tryptophan, via two enzymatic steps. According to a 2010 study in "Endocrinology," orally-administered serotonin does not effectively enter the brain. However, serotonin's precursors, L-tryptophan and 5-HTP, can cross the blood brain barrier and enter the brain. Hence, foods or supplements containing serotonin's precursors could help to elevate brain serotonin levels.
L-Tryptophan Foods
In "Staying Healthy with Nutrition" author Dr. Elson Haas lists a variety of tryptophan-containing foods, but he notes that no food contains particularly high levels. Meats, poultry, dairy products, eggs and some nuts and seeds contain tryptophan. Phyllis Balch, in her book, "Prescription for Herbal Healing," recommends bananas, dates, figs, tuna, whole-grain crackers and yogurt for elevating your tryptophan levels. The University of Maryland Medical Center reports that 5-HTP, serotonin's other precursor, is not present in any foods but can be obtained from the seeds of an African plant called Griffonia simplicifolia.
Considerations
It is normal for people to feel blue from time to time. True depression, however, is a serious condition, with symptoms ranging from mild sadness to suicidal behavior. Eating foods or taking supplements to alter the levels of neurotransmitters in your brain may offer some benefit, but these remedies are unlikely to confer sustained improvement or address major depression. If you think you are depressed, consult a healthcare professional.
References
- "American Family Physician"; Screening for Depression Across the Lifespan: A Review of Measures for Use in Primary Care Settings; L.K. Sharp, M.S. Lipsky; September 2002
- "The Merck Manual of Diagnosis and Therapy, 18th Edition: Depressive Disorders; Mark H. Beers, M.D., Editor-In-Chief; 2006
- "Endocrinology"; Peripheral Serotonin Enhances Lipid Metabolism by Accelerating Bile Acid Turnover; H. Watanabe et al.; October 2010
- "Staying Healthy with Nutrition: Tryptophan"; Elson M. Haas, M.D.; 2006
- "Prescription for Herbal Healing: Insomnia"; Phyllis A. Balch, CNC; 2002
- University of Maryland Medical Center; 5-Hydroxytryptophan (5-HTP); 2006
