Integrative Laboratory of Applied Physiology and Lifestyle Medicine
Iowa City, Iowa, 52242, United States
NCT Number: NCT05928195
Guayusa extract is a caffeinated tea leaf unique blend of antioxidants and caffeine. It is marketed as an ingredient that can help support energy and performance with potential health-related benefits. It has also been indicated as being as safe as any other existing teas (i.e., green tea). However, no studies have previous studied the dose-response effects of guayusa extract for supporting cognitive function, mood, metabolism, nor its effects on resting heart rate, blood pressure, and electrocardiogram characteristics.
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Notify Me18 year–45 year
All sexes
Interventional
Not applicable
Iowa City, Iowa, 52242, United States
Guayusa extract is a caffeinated Amazonian 'super-leaf' belonging to the holly species that contains a unique blend of polyphenol antioxidants and caffeine (~20% caffeine, 30% chlorogenic acids, 5% catechins). It is also remarkably low in tannins which are responsible for the bitter taste found in most teas - giving it a sweet flavor profile. As such, it is marketed as an ingredient that can help support energy and performance (e.g., via caffeine content) with potential health-related benefits due to its antioxidant properties. Indeed, ingredients such as these are often consumed by individuals prior to exercise in order to help improve neurocognitive performance, mood, or otherwise to support health-related goals such as metabolism. Whereas several studies have suggested that caffeine and chlorogenic acid consumption may improve performance, mood, and concentration, and some evidence in animals have linked catechin consumption to improved health outcomes, no studies have previous studied whether guayusa extract supplementation helps to support these, nor has the dose-effectiveness been tested, in humans.
In this study, the effects of acute dietary supplementation with two different doses of botanical organic guayusa extract on neurocognitive/motor-cognitive performance, mood, focus, and jitteriness, resting metabolism, and resting heart rate, blood pressure, and electrocardiogram characteristics will be examined.
Healthy volunteers accepted: Yes
Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
Exclusion criteria
Participants will consume two vegan capsules with one capsule containing 600 mg AmaTea® and 1 containing 600 mg dextrose.
Participants will consume two vegan capsules with each capsule containing 600 mg AmaTea® (1200 mg total).
Participants will consume two vegan capsules with each capsule containing 600 mg dextrose (1200 mg total).
Time frame: 90-minutes Post-supplementation
Calculated as Total Mood Disturbance (arbitrary units) using the Profile of Mood States Short Form Questionnaire.
Time frame: 60-minutes Post-supplementation
How well participant perceived, attends, responds to visual-perceptive information, and performs motor speed and fine motor coordination. Calculated as the sum of finger taps in finger tapping test and correct responses in the symbol digit coding test.
Time frame: 60-minutes Post-supplementation
How well participant recognized rules, categories, and manages or navigates rapid decisions making. Calculated as the differences between Shifting Attention Test Correct Responses and Errors.
Time frame: 90-minutes Post-supplementation
Participants will describe how jittery they feel after supplemention using a 0-100 mm visual analog scale.
Time frame: 90-minutes Post-supplementation
Participants will describe how focused they feel after supplemention using a 0-100 mm visual analog scale.
Time frame: 90-minutes Post-supplementation
Participants will describe how energetic they feel after supplemention using a 0-100 mm visual analog scale.
Time frame: 50 minutes post-supplementation
Resting metabolic rate (kcal/min) will be quantified from resting, fasted analyses of pulmonary gas exchange.
Time frame: 50 minutes post-supplementation
Resting fat oxidation (g/min) will be quantified from resting, fasted analyses of pulmonary gas exchange.
Time frame: -10 minutes before supplementation, 40 minutes post-supplementation
Heart rate (bpm) will be quantified from a standard 12-lead ECG
Time frame: -10 minutes before supplementation, 40 minutes post-supplementation
Systolic, diastolic, and pulse pressures (mmHg) will be quantified from brachial artery via automated sphygmomanometer.
Time frame: -10 minutes before supplementation, 40 minutes post-supplementation
QTc Interval (ms) will be quantified from a standard 12-lead ECG
Time frame: 100-minutes Post-supplementation
Motor-cognitive reaction times (ms) will be quantified from motor cognitive (reactionary hop) tests
Time frame: 60-minutes Post-supplementation
How well a subject can direct and focus cognitive activity on specific stimuli. Derived from performance on the 4-part continuous performance task test.
Time frame: 60-minutes Post-supplementation
How well a subject can perceive and attend to symbols using short-term memory processes.
Time frame: 60-minutes Post-supplementation
How well subject is able to adapt to rapidly changing and increasingly complex set of directions and/or to manipulate the information. Assessed from the Shifting Attention Task and Stoop Test as the Shifting Attention Task Correct Responses - Shifting Attention Task Incorrect Responses and Stroop Commission Errors.
Time frame: 90-minutes Post-supplementation
Vigor will be quantified using the Profile of Mood State Short Form Questionnaire.
Time frame: 90-minutes Post-supplementation
Tension will be quantified using the Profile of Mood State Short Form Questionnaire.
Time frame: 90-minutes Post-supplementation
Fatigue will be quantified using the Profile of Mood State Short Form Questionnaire.
Time frame: 90-minutes Post-supplementation
Anger will be quantified using the Profile of Mood State Short Form Questionnaire.
Time frame: 90-minutes Post-supplementation
Confusion will be quantified using the Profile of Mood State Short Form Questionnaire.
Time frame: 90-minutes Post-supplementation
Stress will be quantified using the Profile of Mood State Short Form Questionnaire.
Time frame: 60-minutes Post-supplementation
How well subject can recognize, remember, and retrieve words and geometric figures. Assessed as a composite performance indicator during the Verbal Memory and Visual Memory Tests.
Time frame: 60-minutes Post-supplementation
How quickly the subject can react, in milliseconds, to a simple and increasingly complex direction set.
Time frame: 60-minutes Post-supplementation
Ability to track and respond to a variety of stimuli over lengthy periods of time and/or perform mental tasks requiring vigilance quickly and accurately.
Time frame: 60-minutes Post-supplementation
How well is subject able to recognize, reason and respond to non-verbal visual-abstract stimuli. Assessed from the non-verbal reasoning test as the difference between the number of correct responses and commission errors.
Nathaniel Jenkins
Other
Acute, Dose-Response Effects of Organic Guayusa Extract on Cognitive Performance, Mood, Resting Metabolism, and Blood Pressure, Heart Rate, and Heart Electrical Activity
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View the official ClinicalTrials.gov record (opens in a new tab)This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.