Tryptophan Intake for Healthy Adults

Overseen By Nisha Pai, MSc, RD

Age: 18 - 65

Sex: Male

Trial Phase: Academic

Sponsor: The Hospital for Sick Children

Must not be taking: Steroids, Anti-inflammatories, SSRIs, others

Disqualifiers: Diabetes, Cancer, Liver disease, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

Duration: 10 hours

6 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

The trial aims to develop a method to measure harmful compounds produced when tryptophan breaks down. Tryptophan, an important nutrient, helps produce serotonin, which the brain needs to function well. In stressful situations, such as when premature babies receive nutrition intravenously, tryptophan can convert into harmful compounds. The trial involves healthy adults taking different levels of tryptophan to aid in creating a measurement method for these compounds. It is suitable for individuals aged 18 to 45 who are generally healthy and not on medications affecting protein metabolism. As an unphased trial, this study offers a unique opportunity to contribute to foundational research that could improve health outcomes for vulnerable populations.

Do I need to stop taking my current medications for the trial?

Yes, you will need to stop taking medications that affect protein or amino acid metabolism, such as steroids, anti-inflammatory drugs, acetaminophen, and SSRIs.

What prior data suggests that this method is safe for measuring tryptophan breakdown in adults?

Research shows that tryptophan is generally safe for short-term use in healthy adults. Studies have found that taking up to 5 grams per day for 21 days is usually well-tolerated. Some individuals might experience mild side effects such as drowsiness, stomach ache, or nausea, particularly at higher doses between 70 and 200 mg per kilogram of body weight. Tryptophan may pose risks for certain conditions, like bladder cancer or cataracts, though these are less common. Overall, short-term use of tryptophan is typically safe for most healthy adults, but monitoring the body's reactions is advisable. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Most treatments for improving mood and well-being often involve medications that alter brain chemistry indirectly. But tryptophan works differently, as it is a natural amino acid and a building block for serotonin, a neurotransmitter linked to happiness and relaxation. Unlike synthetic drugs, tryptophan is a dietary component, making it potentially more accessible and with fewer side effects. Researchers are excited about tryptophan because it offers a more natural approach to enhancing mood and could be easily incorporated into everyday diet plans.

What evidence suggests that this method is effective for measuring tryptophan breakdown?

Research shows that tryptophan plays a key role in mood and sleep. Studies have found that taking tryptophan can improve sleep and reduce depression levels. Some controlled trials suggest that taking 3 to 6 grams of tryptophan daily might be as effective as antidepressant medications. Consuming foods high in tryptophan may also enhance mood in people with depression. While tryptophan is vital for brain health, it can convert into harmful substances when the body is under stress, particularly in premature babies receiving intravenous nutrition. This trial will test tryptophan intake levels in healthy young adults to develop a method for measuring these harmful substances in adults, which could eventually benefit preterm babies. ^{5 6 7 8 9}

Who Is on the Research Team?

Glenda Courtney-Martin, PhD, RD

Principal Investigator

The Hospital for Sick Children

Are You a Good Fit for This Trial?

This trial is for healthy young adults. Specific eligibility criteria are not provided, but typically participants should have no significant health issues that could interfere with the study.

Inclusion Criteria

My blood sugar and kidney function tests are within normal ranges.

I am in good health overall.

Consent provided

Exclusion Criteria

I am willing to have blood drawn and participate in all required study procedures.

Inability to tolerate the diet (i.e. allergy)

Significant weight loss during the past month or consumption of weight reducing diets

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive varying levels of tryptophan intake to study its metabolism

10 hours

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

2 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Tryptophan

Trial Overview The study aims to develop a method to measure compounds resulting from tryptophan breakdown. This will help understand its metabolism in stressed conditions like those experienced by premature babies on TPN.

How Is the Trial Designed?

Group I: Experimental: Tryptophan in healthy young adults (18-45 years) Experimental Treatment 1 Intervention

Tryptophan intake levels, up to 5 levels, will be tested in a random order in all subjects

Who Is Running the Clinical Trial?

The Hospital for Sick Children

Lead Sponsor

Trials

724

Recruited

6,969,000+

Canadian Institutes of Health Research (CIHR)

Collaborator

Trials

1,417

Recruited

26,550,000+

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC2908021/

L-Tryptophan: Basic Metabolic Functions, Behavioral ... Some of the earliest studies found modest mood-lowering effects following acute tryptophan depletion in samples of healthy young men. Since then ...

2. sciencedirect.com sciencedirect.com/science/article/pii/S0022316623008143

Tryptophan Intake in the US Adult Population Is Not ... Tryptophan intake was inversely associated with self-reported level of depression and positively associated with sleep duration.

3. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/32272859/

A systematic review of the effect of L-tryptophan ... This suggests that TRP intake may be an effective approach to decrease anxiety and increase positive mood in healthy individuals. On the other hand, the ...

4. peacehealth.org peacehealth.org/medical-topics/id/hn-10006312

L-Tryptophan – Health Information Library Several controlled trials found that 3 to 6 grams per day of L-tryptophan were equally as effective as antidepressant medications. Some, though not all, double ...

5. mdpi.com mdpi.com/2072-6643/15/4/847

Beneficial Effect of Increased Tryptophan Intake on Its ... Results of several studies suggest a beneficial effect of a TRP-rich diet in individuals with depressed mood. An average daily intake of TRP is 3.5–5.0 mg per ...

6. webmd.com webmd.com/vitamins/ai/ingredientmono-326/l-tryptophan

L-Tryptophan - Uses, Side Effects, and More L-tryptophan supplements are possibly safe when taken for up to 3 weeks. L-tryptophan can cause some side effects such as drowsiness, stomach pain, vomiting, ...

7. mayoclinic.org mayoclinic.org/drugs-supplements/tryptophan-oral-route/description/drg-20064453

Tryptophan (oral route) - Side effects & dosage Bladder cancer—L-tryptophan may increase the risk of bladder cancer; Cataracts—L-tryptophan may cause cataracts; Diabetes mellitus (sugar diabetes)—L-tryptophan ...

8. sciencedirect.com sciencedirect.com/science/article/pii/S0022316622026001

Effects and Side Effects Associated with the Non-Nutritional ... Though the literature is thin, occasional side effects, seen mainly at higher doses (70–200 mg/kg), include tremor, nausea, and dizziness.

9. health.com health.com/tryptophan-benefits-8704946

Tryptophan: Benefits, Uses, Side Effects, and More - Health ... safety and dosage. Is Tryptophan Safe? Doses of up to 5 grams of tryptophan daily for 21 days have been reported as safe for healthy adults.