Food sources of tryptophan include red meat, dairy products, nuts, seeds, legumes, soybeans and soy products, tuna, shellfish, and turkey.
For serving size for specific foods see the Nutrient Rating Chart.
Tryptophan is one of the 10 essential amino acids that the body uses to synthesize the proteins it needs. It's well-known for its role in the production of nervous system messengers, especially those related to relaxation, restfulness, and sleep.
Tryptophan has two important functions. First, a small amount of the tryptophan we get in our diet (about 3%) is converted into niacin (vitamin B3) by the liver. This conversion can help prevent the symptoms associated with niacin deficiency when dietary intake of this vitamin is low.
Second, tryptophan serves as a precursor for serotonin, a neurotransmitter that helps the body regulate appetite, sleep patterns, and mood. Because of its ability to raise serotonin levels, tryptophan has been used therapeutically in the treatment of a variety of conditions, most notably insomnia, depression, and anxiety.
As an essential amino acid, dietary deficiency of tryptophan may cause the symptoms characteristic of protein deficiency, which include weight loss and impaired growth in infants and children.
When accompanied by dietary niacin deficiency, lack of tryptophan in the diet may also cause pellagra, the classic niacin deficiency disease that is characterized by the "4 Ds" —dermatitis, diarrhea, dementia, and death. This condition is very rare in the United States, however, and cannot occur simply because of a tryptophan deficiency.
Dietary deficiency of tryptophan may lead to low levels of serotonin. Low serotonin levels are associated with depression, anxiety, irritability, impatience, impulsiveness, inability to concentrate, weight gain, overeating, carbohydrate cravings, poor dream recall, and insomnia.
High dietary intake of tryptophan from food sources is not known to cause any symptoms of toxicity. In addition, tryptophan has been given therapeutically, as a prescription medicine or dietary supplement, in doses exceeding five grams per day with no report of adverse effects.
However, in 1989, the use of dietary supplements containing tryptophan was blamed for the development of a serious condition called eosinophilia-myalgia syndrome (EMS), which caused severe muscle and joint pain, high fever, weakness, swelling of the arms and legs, and shortness of breath in more than a thousand people. In addition, more than 30 deaths were attributed to EMS caused by tryptophan supplements.
Many experts believe that the EMS was caused by a contaminant that was found in one batch of tryptophan sold by one manufacturer and occurred in only a small number of susceptible individuals. However, the United States Food and Drug Administration, the agency responsible for overseeing the dietary supplement industry, remained convinced that high doses of tryptophan were categorically unsafe. Since 1989, tryptophan has not been available as a dietary supplement in the United States.
To date, a Tolerable Upper Intake Level (TUL) for tryptophan has not yet been established by the Institute of Medicine at the National Academy of Sciences.
There is no research showing problematic effects of cooking, storage, or processing on tryptophan levels in food.
Vitamin B6 is necessary for the conversion of tryptophan to both niacin and serotonin. Consequently, a dietary deficiency of vitamin B6 may result in low serotonin levels and/or impaired conversion of tryptophan to niacin.
In addition, several dietary, lifestyle, and health factors reduce the conversion of tryptophan to serotonin, including cigarette smoking, high sugar intake, alcohol abuse, excessive consumption of protein, hypoglycemia and diabetes.
Because of this, some healthcare practitioners believe that food sources of tryptophan do not cause a significant enough increase in blood levels of tryptophan to produce therapeutic results, and that tryptophan must, therefore, be taken as a supplement to increase its blood levels.
Tryptophan may play a role in the prevention and/or treatment of the following health conditions::
Tryptophan occurs naturally in nearly all foods that contain protein, but in small amounts compared to the other essential amino acids. The following foods contain tryptophan: red meat, dairy products, nuts, seeds, legumes, soybeans and soy products, tuna, shellfish, and turkey.
World's Healthiest Foods ranked as quality sources of tryptophan |
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Food | Serving Size |
Cals | Amount (g) |
DV (%) |
Nutrient Density |
World's Healthiest Foods Rating |
Chicken | 4 oz | 187.1 | 0.41 | 157.69 | 15.2 | excellent |
Soybeans | 1 cup | 297.6 | 0.39 | 150.00 | 9.1 | excellent |
Turkey | 4 oz | 166.7 | 0.36 | 138.46 | 15.0 | excellent |
Tuna | 4 oz | 147.4 | 0.35 | 134.62 | 16.4 | excellent |
Salmon | 4 oz | 157.6 | 0.30 | 115.38 | 13.2 | excellent |
Lamb | 4 oz | 350.4 | 0.30 | 115.38 | 5.9 | excellent |
Shrimp | 4 oz | 134.9 | 0.28 | 107.69 | 14.4 | excellent |
Tofu | 4 oz | 164.4 | 0.28 | 107.69 | 11.8 | excellent |
Cod | 4 oz | 96.4 | 0.26 | 100.00 | 18.7 | excellent |
Sardines | 3.20 oz | 188.7 | 0.25 | 96.15 | 9.2 | excellent |
Scallops | 4 oz | 125.9 | 0.20 | 76.92 | 11.0 | excellent |
Spinach | 1 cup | 41.4 | 0.07 | 26.92 | 11.7 | excellent |
Beet Greens | 1 cup | 38.9 | 0.06 | 23.08 | 10.7 | excellent |
Asparagus | 1 cup | 39.6 | 0.05 | 19.23 | 8.7 | excellent |
Mushrooms, Crimini | 1 cup | 15.8 | 0.04 | 15.38 | 17.5 | excellent |
Bok Choy | 1 cup | 20.4 | 0.03 | 11.54 | 10.2 | excellent |
Soy Sauce | 1 TBS | 10.8 | 0.03 | 11.54 | 19.2 | excellent |
Kidney Beans | 1 cup | 224.8 | 0.18 | 69.23 | 5.5 | very good |
Black Beans | 1 cup | 227.0 | 0.18 | 69.23 | 5.5 | very good |
Dried Peas | 1 cup | 231.3 | 0.18 | 69.23 | 5.4 | very good |
Pinto Beans | 1 cup | 244.5 | 0.18 | 69.23 | 5.1 | very good |
Navy Beans | 1 cup | 254.8 | 0.18 | 69.23 | 4.9 | very good |
Lima Beans | 1 cup | 216.2 | 0.17 | 65.38 | 5.4 | very good |
Pumpkin Seeds | 0.25 cup | 180.3 | 0.17 | 65.38 | 6.5 | very good |
Lentils | 1 cup | 229.7 | 0.16 | 61.54 | 4.8 | very good |
Garbanzo Beans | 1 cup | 269.0 | 0.14 | 53.85 | 3.6 | very good |
Barley | 0.33 cup | 217.1 | 0.13 | 50.00 | 4.1 | very good |
Sesame Seeds | 0.25 cup | 206.3 | 0.12 | 46.15 | 4.0 | very good |
Sunflower Seeds | 0.25 cup | 204.4 | 0.10 | 38.46 | 3.4 | very good |
Oats | 0.25 cup | 151.7 | 0.09 | 34.62 | 4.1 | very good |
Wheat | 1 cup | 151.1 | 0.09 | 34.62 | 4.1 | very good |
Cheese | 1 oz | 114.2 | 0.08 | 30.77 | 4.8 | very good |
Buckwheat | 1 cup | 154.6 | 0.08 | 30.77 | 3.6 | very good |
Eggs | 1 each | 77.5 | 0.08 | 30.77 | 7.1 | very good |
Milk | 4 oz | 74.4 | 0.05 | 19.23 | 4.7 | very good |
Broccoli | 1 cup | 54.6 | 0.05 | 19.23 | 6.3 | very good |
Collard Greens | 1 cup | 62.7 | 0.05 | 19.23 | 5.5 | very good |
Flax Seeds | 2 TBS | 74.8 | 0.04 | 15.38 | 3.7 | very good |
Brussels Sprouts | 1 cup | 56.2 | 0.04 | 15.38 | 4.9 | very good |
Swiss Chard | 1 cup | 35.0 | 0.03 | 11.54 | 5.9 | very good |
Mustard Greens | 1 cup | 36.4 | 0.03 | 11.54 | 5.7 | very good |
Turnip Greens | 1 cup | 28.8 | 0.03 | 11.54 | 7.2 | very good |
Miso | 1 TBS | 34.2 | 0.03 | 11.54 | 6.1 | very good |
Cauliflower | 1 cup | 28.5 | 0.03 | 11.54 | 7.3 | very good |
Kale | 1 cup | 36.4 | 0.03 | 11.54 | 5.7 | very good |
Cashews | 0.25 cup | 221.2 | 0.10 | 38.46 | 3.1 | good |
Quinoa | 0.75 cup | 222.0 | 0.10 | 38.46 | 3.1 | good |
Peanuts | 0.25 cup | 206.9 | 0.09 | 34.62 | 3.0 | good |
Sweet Potato | 1 medium | 180.0 | 0.08 | 30.77 | 3.1 | good |
Millet | 1 cup | 207.1 | 0.07 | 26.92 | 2.3 | good |
Brown Rice | 1 cup | 216.4 | 0.06 | 23.08 | 1.9 | good |
Rye | 0.33 cup | 188.5 | 0.06 | 23.08 | 2.2 | good |
Walnuts | 0.25 cup | 196.2 | 0.05 | 19.23 | 1.8 | good |
Green Peas | 1 cup | 115.7 | 0.05 | 19.23 | 3.0 | good |
Onions | 1 cup | 92.4 | 0.04 | 15.38 | 3.0 | good |
Yogurt | 1 cup | 149.4 | 0.04 | 15.38 | 1.9 | good |
Almonds | 0.25 cup | 132.2 | 0.04 | 15.38 | 2.1 | good |
Potatoes | 1 medium | 160.9 | 0.04 | 15.38 | 1.7 | good |
Winter Squash | 1 cup | 75.8 | 0.03 | 11.54 | 2.7 | good |
Beets | 1 cup | 74.8 | 0.03 | 11.54 | 2.8 | good |
Corn | 1 each | 73.9 | 0.02 | 7.69 | 1.9 | good |
Cabbage | 1 cup | 43.5 | 0.02 | 7.69 | 3.2 | good |
Green Beans | 1 cup | 43.8 | 0.02 | 7.69 | 3.2 | good |
Thyme | 2 TBS | 4.8 | 0.01 | 3.85 | 14.3 | good |
Bell Peppers | 1 cup | 28.5 | 0.01 | 3.85 | 2.4 | good |
Watermelon | 1 cup | 45.6 | 0.01 | 3.85 | 1.5 | good |
Basil | 0.50 cup | 4.9 | 0.01 | 3.85 | 14.2 | good |
Apricot | 1 whole | 16.8 | 0.01 | 3.85 | 4.1 | good |
Tomatoes | 1 cup | 32.4 | 0.01 | 3.85 | 2.1 | good |
Cucumber | 1 cup | 15.6 | 0.01 | 3.85 | 4.4 | good |
Romaine Lettuce | 2 cups | 16.0 | 0.01 | 3.85 | 4.3 | good |
Sea Vegetables | 1 TBS | 10.8 | 0.01 | 3.85 | 6.4 | good |
Kiwifruit | 1 2 inches | 42.1 | 0.01 | 3.85 | 1.6 | good |
Plum | 1 2-1/8 inches | 30.4 | 0.01 | 3.85 | 2.3 | good |
Leeks | 1 cup | 32.2 | 0.01 | 3.85 | 2.1 | good |
Grapefruit | 0.50 medium | 41.0 | 0.01 | 3.85 | 1.7 | good |
Garlic | 6 cloves | 26.8 | 0.01 | 3.85 | 2.6 | good |
Summer Squash | 1 cup | 36.0 | 0.01 | 3.85 | 1.9 | good |
Strawberries | 1 cup | 46.1 | 0.01 | 3.85 | 1.5 | good |
Mustard Seeds | 2 tsp | 20.3 | 0.01 | 3.85 | 3.4 | good |
Eggplant | 1 cup | 34.6 | 0.01 | 3.85 | 2.0 | good |
Celery | 1 cup | 16.2 | 0.01 | 3.85 | 4.3 | good |
World's Healthiest Foods Rating |
Rule |
---|---|
excellent | DV>=75% OR Density>=7.6 AND DV>=10% |
very good | DV>=50% OR Density>=3.4 AND DV>=5% |
good | DV>=25% OR Density>=1.5 AND DV>=2.5% |
In its most recent 2005 public health recommendations for amino acids (published as the Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients), National Academies Press, 2005), the National Academy of Sciences (NAS) established a general principle for tryptophan intake. The NAS recommended that all individuals 1 year of age or greater consume 7 milligrams of tryptophan for every 1 gram of food protein. Here is how that recommendation would look for each age and gender group, assuming RDA-level protein intake for each group: