Theanine and Caffeine on Neurophysiology of Attention

NCT02770105 | Completed

• 1 other identifier: TTUIRB505445
• Study Type: interventional
• Target: 9
• Locations: 1 country
• Sites: 1

Brief Summary

L-theanine and caffeine are nutritional compounds that are naturally found in tea. Our recent findings using an EEG paradigm are consistent with the findings of others, indicating that intake of L-theanine and caffeine reduce the time needed for a person to differentiate between two visual stimuli and react to only one stimulus. In order to understand how these compounds give rise to these improvements, the investigators need to study how these compounds are related to various areas of the brain. To achieve this, the investigators plan to scan the brains of nine participants after they take either 1) L-theanine alone, 2) caffeine alone 3) the combination of both L-theanine and caffeine as compared with a placebo (distilled water), to see which has the greatest impact on attention and on regions in the brain that bring about attention.

Conditions

L-theanine

Keywords

L-theanine; caffeine; selective attention; fMRI; RVRT

Outcome Measures

Primary Outcomes (1)

• Differences between fMRI blood oxygen level dependent (BOLD) responses of the brain recorded following administration of each substance and the placebo

  Theanine, caffeine, theanine-caffeine combination and distilled water (placebo) will be administered on 4 separate days (at least 5 days apart) in a random order. Functional MRI scans will be performed 60 minutes after each administration. Primary outcome measure will be the difference in fMRI BOLD responses obtained for each substance and the placebo.

  Sixty minutes after administration of each of theanine, caffeine, theanine-caffeine combination and placebo

Secondary Outcomes (3)

• Differences between mean recognition visual reaction times recorded following administration of each substance and the placebo

  Sixty minutes after administration of each of theanine, caffeine, theanine-caffeine combination and placebo

• Differences between proportion of errors caused while performing the recognition visual reaction time task following administration of each substance and the placebo

  Sixty minutes after administration of each of theanine, caffeine, theanine-caffeine combination and placebo

• Differences between proportion of omissions caused while performing the recognition visual reaction time task following administration of each substance and the placebo

  Sixty minutes after administration of each of theanine, caffeine, theanine-caffeine combination and placebo

Interventions

Theanine OTHER

Oral administration of 200mg of L-theanine powder dissolved in 200ml of distilled water

Caffeine OTHER

Oral administration of 160mg of anhydrous caffeine powder dissolved in 200ml of distilled water

Theanine-Caffeine Combination OTHER

Oral administration of 200mg of L-theanine and 160mg of anhydrous caffeine powder, dissolved in 200ml of distilled water

Placebo OTHER

Oral administration of 200ml of distilled water

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy males\*
• Age 18-60 years

You may not qualify if:

• Gross impairment of vision or hearing that would prevent the participants from recognizing visual stimuli
• Physical, psychiatric or neurological impairment that could affect cognitive or motor functions
• Exposure to toxins or substances that are known to affect visual, auditory, cognitive or motor functions
• Regular intake of medication that could alter visual, auditory, cognitive or motor functions
• History of and / or current alcohol and / or drug abuse
• Disease or condition known to be precipitated or aggravated by tea or coffee
• Intake of drugs containing caffeine, other phosphodiesterase inhibitors or adenosine receptor blockers
• Intake of medications which are known to have pharmacological interactions with caffeine
• Participants with contra-indications to undergo fMRI scanning
• Unwilling or unable to discontinue the use of cell phones, smart phones or other electronic devices during the entire study visit.

Sponsors & Collaborators

• Texas Tech University: lead

Study Sites (1)

Texas Tech University - Department of Nutritional Sciences

Lubbock, Texas, 79409, United States

Location

Related Publications (3)

• Kahathuduwa CN, Dassanayake TL, Amarakoon AMT, Weerasinghe VS. Acute effects of theanine, caffeine and theanine-caffeine combination on attention. Nutr Neurosci. 2017 Jul;20(6):369-377. doi: 10.1080/1028415X.2016.1144845. Epub 2016 Feb 12.

  PMID: 26869148 BACKGROUND

• Weerasinghe V, Kahathuduwa C, Amarakoon T, Dassanayake T. Synergistic Effect of Theanine and Caffeine on Visual Reaction Time, Evoked Potentials and Cognitive Event Related Potentials. Journal of Clinical Neurophysiology. 2015; 32(4): S396.

  BACKGROUND

• Camfield DA, Stough C, Farrimond J, Scholey AB. Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis. Nutr Rev. 2014 Aug;72(8):507-22. doi: 10.1111/nure.12120. Epub 2014 Jun 19.

  PMID: 24946991 BACKGROUND

MeSH Terms

Interventions

theanine; Caffeine

Intervention Hierarchy (Ancestors)

Xanthines; Alkaloids; Heterocyclic Compounds; Purinones; Purines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring

Study Officials

• Martin Binks, PhD

  Texas Tech University - Department of Nutritional Sciences

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 6, 2016
• First Posted: May 12, 2016
• Study Start: May 1, 2016
• Primary Completion: June 1, 2016
• Study Completion: June 1, 2016
• Last Updated: September 2, 2016

Record last verified: 2016-05

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)