When people think of tryptophan, one word mostly comes to mind: turkey. This is really a funny thing to me. Tryptophan health benefits are very promising and vast.
Let’s explore this substance called tryptophan, which is so much more than a Thanksgiving nap-inducer.
Turkey isn’t even in the top 5 high-tryptophan foods. But, it is in the conversation.
Tryptophan, like many amino acids in foods, doesn’t get the respect it deserves. It has numerous roles in the body as a neurotransmitter and hormone precursor.
It is essential to the body, meaning it can’t be made within the body; we need to get it from food or supplemental sources.
Food Sources of Tryptophan
Tryptophan’s full name is L-tryptophan or 5-hydroxytryptophan (5-HTP). These are the forms that are available in supplements.
As for amounts in foods, keep in mind, 100 grams of food is equal to about 1/4 of a pound or 4 ounces. That would be a lot of spirulina, seeds or cheese.
That amount of cheese would provoke a belly ache for many people, while 4 oz of turkey or lamb may not.
Tryptophan tends to cozy up with other amino acids for absorption, so its effects at turkey dinner time are even less than they might be if you just had straight tryptophan.
The sleepy turkey dinner phenomenon results mostly as a result of a large amount of calories being digested, forcing a large amount of blood supply to be focused on digestion, an intensive process with all that food.
Sleepy time indeed.
Do People Get Tryptophan Deficiency?
Yes. But it is often difficult to tease this out because people who run low in tryptophan would also be low in other amino acids and nutrients.
Think of a person on a limited budget or who has preference for carbohydrate foods and eats little else.
Others who might be low in tryptophan might be chronically ill with a poor appetite.
These people do not get enough amino acids in their daily intake.
Think poor college student who eats ramen noodle meals, pasta, and toast. Mix, match and repeat. Think poverty or eating disorders; you will likely see some symptoms of deficiency.
Tryptophan Sleep Benefits
Tryptophan is the precursor to serotonin, which in turn is a precursor to melatonin. Fun fact for your next party. Everyone knows about melatonin and sleep, but few people know how it is made.
Tryptophan is necessary for sleep.
It may even help sleep quality in people with obstructive sleep apnea .
Tryptophan Mood Benefits
Tryptophan is the building block of serotonin, a mood-enhancing neurotransmitter.
Without tryptophan, depressive symptoms kick in . That is not to say that tryptophan is the only factor in mood, but one of the factors involved in making a person feel calm and happy.
A lesser-known, but certainly important function of tryptophan related to mood is that it is a precurser to a substance called kynurenine.
90% of tryptophan metabolism is dedicated to making kynurenine, which is involved in behavior and memory . Research on this topic remains early.
Tryptophan in clinical research in total appears to be helpful for depression. One extremely important bit of information:
You MUST talk to your doctor before adding tryptophan, as it may have serious interactions with SSRI or other depression medications, especially at higher doses.
In a meta-analysis or compilation-type study, reduced blood levels of tryptophan were found in patients with major depression not receiving medications .
Some depressed patients don’t suffer from low serotonin levels. In these cases, tryptophan will not improve symptoms.
Tryptophan supplements may help with symptoms of PMS, especially dysphoria, tension, and irritability .
Tryptophan Anxiety Benefits
Tryptophan depletion in humans seems to worsen symptoms of stress and anxiety in people who have obsessive-compulsive disorder .
Tryptophan Appetite Effects
Perhaps the strongest research with tryptophan is related to its ability to reduce appetite in clinical studies.
Tryptophan given as 5-HTP reduced appetite and food intake and helped with weight loss(8 mg/kg body weight) over a 5 week period . Given at 900 mg per day, it also resulted in reduced appetite and weight over a 6 month period..
5-HTP also seems to help with weight loss and reduces appetite in people with diabetes .
Patients with bulimia who were depleted of tryptophan ate over 1/3 more food than those not depleted; they also were more irritable .
Niacin, one of the B vitamins involved in energy production, can be made from tryptophan if enough cofactors like B-6 and iron are present.
Deficiency of both niacin and tryptophan have the same result: a disease called pellagra. Symptoms of this disease include the 4 D’s: delusions, diarrhea, depression, and dermatitis.
While overt deficiencies are rare, poor quality diets can elicit subtle symptoms that go undetected all of the time.
Tryptophan and Memory
Depletion of tryptophan impairs memory .
Tryptophan, Migraine, and Motion Sickness
Depletion of tryptophan may result in worsening of dizziness, nausea, and illusion of movement .
Depletion also worsens nausea and light-induced pain in migraine sufferers.
Considerations Before Supplementing
- In the 1990’s, L-tryptophan was removed from the market due to some cases of EMS. The supplement in question was traced back to one factory in Japan. Since then, no cases of EMS have been reported.
- Much of the tryptophan on the market today is sold as 5-HTP, which is often naturally sourced from the plant called Griffonia. The label will tell you if it is naturally sourced. No cases of EMS have been linked to 5-HTP.
- A common side effect of supplemental tryptophan is nausea.
- Typical amounts of doses range from 100-300 mg of 5-HTP per day. Higher doses (900 mg) have been used to promote weight loss.
- Click here for other supplementation considerations.
Tryptophan and Tyrosine
Taking tryptophan has a downside; it might deplete another amino acid called tyrosine . Tyrosine is involved in making another neurotransmitter called dopamine.
Some experts suggest that if you take tryptophan, it may also be beneficial to take tyrosine .
Medication Interactions With Tryptophan
Corticosteroids like prednisone may reduce the availability of tryptophan and tyrosine in the blood, especially in depressed patients. This might be why sleep evades people on these medicines .
Serotonin syndrome is a theoretical concern for people who are taking anti-depressants along with tryptophan; however, this has not been seen in people, even when taking prescription anti-depressants .. These studies have all been small.
To be sure, it is always best to check in with your doctor before supplementing.
The information on this website has not been evaluated by the Food & Drug Administration or any other medical body and is shared for educational purposes only. Consult your doctor or healthcare provider before making changes to your supplement regimen or lifestyle.
Heidi Moretti, MS, RD is The Healthy RD. A registered dietitian for 20 years, has a passion for functional nutrition and natural medicine. Has researched supplements and plants as medicine throughout her career. Loves helping people gain function and vitality by tackling the root causes of illness.