Acute Physiological Effects of Organic Guayusa Extract
Conditions
Keywords
dietary supplementation, cognitive performance, metabolism, heart rate, blood pressure, electrocardiogram, mood
Brief summary
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.
Detailed description
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.
Interventions
DIETARY_SUPPLEMENTAcute Moderate-Dose Guayusa Extract Supplementation
Participants will consume two vegan capsules with one capsule containing 600 mg AmaTea® and 1 containing 600 mg dextrose.
DIETARY_SUPPLEMENTAcute High-Dose Guayusa Extract Supplementation
Participants will consume two vegan capsules with each capsule containing 600 mg AmaTea® (1200 mg total).
DIETARY_SUPPLEMENTPlacebo
Participants will consume two vegan capsules with each capsule containing 600 mg dextrose (1200 mg total).
Sponsors
Nathaniel Jenkins
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Intervention model description
Randomized, placebo-controlled, double-blind, crossover study
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* 18-45 years, inclusive * Physically active (\>=150 min/wk or \>=75 min/wk Moderate or Vigorous PA) for \>=3 months * BMI \<= 30 kg/m2 * Otherwise healthy * Habitual caffeine consumption \>=200 mg/day OR 1-week washout of current caffeine usage prior to participation
Exclusion criteria
* Current injury or illness that precludes exercise participation * Current nicotine or cannabis use * Use of prescription ADD/ADHD, anti-depressant, or other central acting medication, or previously diagnosed ADD/ADHD, clinically depressed, or generalized anxiety disorder * Current taking prescription stimulants (i.e., Adderall, Ritalin, Vyvanse, etc.) * Participants with a history of metabolic, hepatorenal, musculoskeletal, autoimmune, or neurologic disease; or currently taking thyroid, hormonal, hyperlipidemic, hypoglycemic, anti-hypertensive, anti-inflammatory, or anti-coagulant medications. * Treated for Metabolic Syndrome or having been clinically diagnosed with, or taking medication for a cardiometabolic-disorder (e.g., Pre-diabetes, Type II diabetes, high blood pressure, obesity, hypercholesterolemia, etc.) * Currently pregnant or lactating * Diagnosed allergy to any ingredient present within the study treatments * Current competitive NCAA athlete * Inability or unwillingness to comply with the controls and conditions of the study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mood | 90-minutes Post-supplementation | Calculated as Total Mood Disturbance (arbitrary units) using the Profile of Mood States Short Form Questionnaire. |
| Executive Function | 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. |
| Psychomotor Speed | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Energy | 90-minutes Post-supplementation | Participants will describe how energetic they feel after supplemention using a 0-100 mm visual analog scale. |
| Focus | 90-minutes Post-supplementation | Participants will describe how focused they feel after supplemention using a 0-100 mm visual analog scale. |
| Resting Metabolic Rate | 50 minutes post-supplementation | Resting metabolic rate (kcal/min) will be quantified from resting, fasted analyses of pulmonary gas exchange. |
| Resting Fat Oxidation | 50 minutes post-supplementation | Resting fat oxidation (g/min) will be quantified from resting, fasted analyses of pulmonary gas exchange. |
| Resting Heart Rate | -10 minutes before supplementation, 40 minutes post-supplementation | Heart rate (bpm) will be quantified from a standard 12-lead ECG |
| Resting Blood Pressure | -10 minutes before supplementation, 40 minutes post-supplementation | Systolic, diastolic, and pulse pressures (mmHg) will be quantified from brachial artery via automated sphygmomanometer. |
| QTc Interval | -10 minutes before supplementation, 40 minutes post-supplementation | QTc Interval (ms) will be quantified from a standard 12-lead ECG |
| Motor-Cognitive Reaction Time | 100-minutes Post-supplementation | Motor-cognitive reaction times (ms) will be quantified from motor cognitive (reactionary hop) tests |
| Sustained Attention | 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. |
| Working Memory | 60-minutes Post-supplementation | How well a subject can perceive and attend to symbols using short-term memory processes. |
| Cognitive Flexibility | 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. |
| Jitteriness | 90-minutes Post-supplementation | Participants will describe how jittery they feel after supplemention using a 0-100 mm visual analog scale. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Confusion | 90-minutes Post-supplementation | Confusion will be quantified using the Profile of Mood State Short Form Questionnaire. |
| Stress | 90-minutes Post-supplementation | Stress will be quantified using the Profile of Mood State Short Form Questionnaire. |
| Composite Memory | 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. |
| Reaction Time | 60-minutes Post-supplementation | How quickly the subject can react, in milliseconds, to a simple and increasingly complex direction set. |
| Complex Attention | 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. |
| Reasoning | 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. |
| Fatigue | 90-minutes Post-supplementation | Fatigue will be quantified using the Profile of Mood State Short Form Questionnaire. |
| Tension | 90-minutes Post-supplementation | Tension will be quantified using the Profile of Mood State Short Form Questionnaire. |
| Vigor | 90-minutes Post-supplementation | Vigor will be quantified using the Profile of Mood State Short Form Questionnaire. |
| Anger | 90-minutes Post-supplementation | Anger will be quantified using the Profile of Mood State Short Form Questionnaire. |
Countries
United States
Outcome results
None listed