Effect of Tyrosine Supplementation on Cognitive Performance and Mood During Military Stress
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ClinicalTrials.gov Identifier: NCT01913925 |
Recruitment Status :
Completed
First Posted : August 1, 2013
Last Update Posted : November 3, 2020
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The objective of this research is to determine if tyrosine, an amino acid found in protein-containing foods, will mitigate the cognitive deficits and adverse effects on behavior and mood produced by exposure to military stress. This study was conducted at the US Navy Survive, Evade, Resist, Escape (SERE) school at Brunswick, Maine (ME).
Tyrosine is the dietary precursor of the catecholamine norepinephrine, a key brain neurotransmitter that is critical for the central nervous system (CNS) response to various types of acute stress. Psychological stress increases catecholamine turnover in the brain, increasing the requirement for tyrosine to support synthesis of norepinephrine. Animal and human studies have shown that tyrosine supplementation can produce beneficial effects on cognitive and physiological functions during exposure to a variety of acute stressors.
This project will determine if volunteers treated with supplemental tyrosine during stressful phases of SERE training experience less degradation in cognitive performance and mood than volunteers treated with placebo. Tyrosine or placebo will be administered in a specially developed food bar provided to volunteers. The bar is part of a prototype of ration-component designed for use during assault operations. A between-subjects, double blind experimental design will be employed. Tyrosine, an amino acid found in most protein-containing foods, has been tested in hundreds of volunteers without adverse effects.
Approximately 100 volunteers will be recruited from several SERE classes to ensure up to 80 volunteers complete the study. They will be tested during several portions of SERE. A comprehensive but brief battery of cognitive tests, as well as saliva samples, and heart rate data will be collected in a manner that does not interfere with ongoing training.
Hypotheses:
- Exposure to the stressors of SERE school will adversely impact cognitive performance and mood of volunteers.
- The adverse effects of psychological stress on cognitive performance and mood during SERE school will be reduced when volunteers are given supplemental tyrosine compared to placebo treatment.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Reaction to Severe Stress, Unspecified | Other: Tyrosine-Containing Food Bar Other: Placebo Bar | Not Applicable |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 80 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Double (Participant, Investigator) |
Primary Purpose: | Other |
Official Title: | Effect of Tyrosine Supplementation on Cognitive Performance and Mood During Military Stress |
Study Start Date : | July 2009 |
Actual Primary Completion Date : | October 2009 |
Actual Study Completion Date : | October 2009 |

Arm | Intervention/treatment |
---|---|
Active Comparator: Tyrosine-Containing Food Bar
150 mg/kg dose of tyrosine per administration, administered twice
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Other: Tyrosine-Containing Food Bar |
Placebo Comparator: Placebo bar
0 mg/kg dose of tyrosine per administration, administered twice
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Other: Placebo Bar |
- change from baseline cognitive function compared to cognitive function as measured following treatment administration [ Time Frame: baseline and final week of training (approximately 1 week later) ]

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Ages Eligible for Study: | 18 Years to 39 Years (Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Active duty military enrolled in the US Navy SERE School, Brunswick, ME.
- Fluent in English (non-native English speakers can be enrolled).
Exclusion Criteria:
- None.
[All volunteers enrolled in SERE school require a medical clearance. No additional inclusion or exclusion criteria are necessary.]

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01913925
United States, Maine | |
US Navy SERE School | |
Brunswick, Maine, United States, 04011 |
Principal Investigator: | Harris R. Lieberman, PhD | United States Army Research Institute of Environmental Medicine |
Responsible Party: | United States Army Research Institute of Environmental Medicine |
ClinicalTrials.gov Identifier: | NCT01913925 |
Other Study ID Numbers: |
H08-05 |
First Posted: | August 1, 2013 Key Record Dates |
Last Update Posted: | November 3, 2020 |
Last Verified: | November 2020 |
Stress Disorders, Traumatic, Acute Stress Disorders, Traumatic Trauma and Stressor Related Disorders Mental Disorders |