Mental Fatigue
Conditions
Keywords
cacao, theobromine, flavanols, caffeine, sustained attention, vigilance, vigor, vitality, energy, fatigue
Brief summary
The purpose of this study is to determine which substances in cocoa produces changes in mental energy. This is a double blind study. The primary outcome measures are performance on tasks of sustained attention (serial subtract, continuous performance test and Bakan task) at pre and 90, 120 and 160 minutes post intervention, energy and fatigue symptoms (profile of mood state), and ratings of motivation to perform cognitive tasks. The assigned interventions are the following:
Detailed description
Only one prior study has examined the acute influence of cocoa on mental energy. The purpose of this research is to replicate the previous observations and extend research in four ways: 1) start to determine which substance in cocoa responsible for the effect by including several comparison groups, 2) focus on individuals with average or below average symptoms of mental energy and who are not high consumers of fruits, vegetables and other products containing high amounts of flavonoids in order to learn whether people with low energy accrue a greater benefit, and 3) include additional measures of mental energy plausibly influenced by cocoa to better understand the health consequences of cocoa.
Interventions
OTHERCaffeinated cocoa
70 mg caffeine, 179 mg theobromine, 499 mg flavanols, and 1 packet of Truvia sweetener
OTHERCocoa
21 mg caffeine, 179 mg theobromine, 499 mg flavanols, and 1 packet of Truvia sweetener
OTHERCaffeine
473 ml brewed water containing 66 mg caffeine, caramel coloring and one packet Truvia sweetener
OTHERPlacebo
473 ml of brewed water, caramel coloring and one packet Truvia sweetener
Sponsors
The Hershey Company
University of Georgia
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 34 Years
Healthy volunteers
Yes
Inclusion criteria
* Women and men ages 18-34 * Lower than average feelings of energy (score of \< 13 on Profile of Mood States Vigor scale)
Exclusion criteria
* Pregnant * GI tract disorder * Psychoactive medication use * Daily consumption of \> 200 mg caffeine * Body mass index \> 30 * Cigarette smoker * Allergy to cocoa, chocolate or caffeine * Frequent consumption of cocoa, chocolate-based products or fruits and vegetable containing flavonoids
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Correct Responses on Serial 7 Subtraction Task | Pre and 30, 60 and 120 minutes post intervention | Participants subtract the number 7 from a three digit number and quickly and accurately as possible for 60 seconds. The total number of accurate responses is scored. The higher the score the better performance. The range of scores is from a minimum score of 0 to a theoretical maximum score of 120. |
| Performance on Bakan Task | baseline, post 60, post 90, post 120 | Performance on Bakan Task at baseline, post-test 1, post-test 2, and post-test 3 Bakan test presents numbers on a computer screen. Participant presses one button whenever the number 6 appears and a different button whenever three odd and different numbers in a row occurs such as 7 5 9. The number of times the participant does this correctly the better the performance. The scores range from 0 to 10 because the sequence of three odd and different numbers occurs a total of 10 times. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Vigor Symptoms (Profile of Mood State) | Pre and 90, 120 and 160 minutes post intervention | Vigor subscale scores from the Profile of Mood States.The higher the score the greater the feelings of energy. The scores range from a minimum of 0 to a maximum of 20. |
Countries
United States
Participant flow
Recruitment details
Potential participants were recruited from (i) large university classes, (ii) announcements on buses, bulletin boards, and electronic listservs, and (iii) through word of mouth. Potential participants were invited to complete screening questionnaires (medical history, diet, mood) administered online using Zoomerang \>http://www.zoomerang.com/\<.
Participants by arm
| Arm | Count |
|---|---|
| All Completed Participants These baseline data represent all participants who completed the trial (n = 23). Data are presented as means and standard deviations where appropriate. | 23 |
| Total | 23 |
Baseline characteristics
| Characteristic | All Completed Participants |
|---|---|
| Age, Continuous | 20 years STANDARD_DEVIATION 2 |
| Amount of sleep on a typical night in the past month (hrs) | 7.4 hours STANDARD_DEVIATION 1.1 |
| Height | 168.28 cm STANDARD_DEVIATION 1.19 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 6 Participants |
| Race (NIH/OMB) More than one race | 2 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 15 Participants |
| Region of Enrollment United States | 23 Participants |
| Sex: Female, Male Female | 17 Participants |
| Sex: Female, Male Male | 6 Participants |
| Weight | 67.05 kg STANDARD_DEVIATION 14.87 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 23 | 0 / 23 | 0 / 23 | 0 / 23 |
| serious Total, serious adverse events | 0 / 23 | 0 / 23 | 0 / 23 | 0 / 23 |
Outcome results
Primary
Correct Responses on Serial 7 Subtraction Task
Participants subtract the number 7 from a three digit number and quickly and accurately as possible for 60 seconds. The total number of accurate responses is scored. The higher the score the better performance. The range of scores is from a minimum score of 0 to a theoretical maximum score of 120.
Time frame: Pre and 30, 60 and 120 minutes post intervention
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Pre-test | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Placebo | 40.91 Correct responses | Standard Deviation 5.56 |
| Pre-test | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Caffeine | 41.83 Correct responses | Standard Deviation 3.56 |
| Pre-test | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Cocoa | 42.57 Correct responses | Standard Deviation 2.52 |
| Pre-test | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Caffeine + Cocoa | 42.17 Correct responses | Standard Deviation 3.24 |
| Post-test 1 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Caffeine | 41.35 Correct responses | Standard Deviation 3.73 |
| Post-test 1 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Cocoa | 42.61 Correct responses | Standard Deviation 3.86 |
| Post-test 1 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Caffeine + Cocoa | 42.26 Correct responses | Standard Deviation 2.47 |
| Post-test 1 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Placebo | 42.57 Correct responses | Standard Deviation 3.51 |
| Post-test 2 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Cocoa | 42.78 Correct responses | Standard Deviation 3.06 |
| Post-test 2 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Caffeine | 43.22 Correct responses | Standard Deviation 2.92 |
| Post-test 2 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Caffeine + Cocoa | 42.96 Correct responses | Standard Deviation 2.33 |
| Post-test 2 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Placebo | 43.04 Correct responses | Standard Deviation 2.31 |
| Post-test 3 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Caffeine + Cocoa | 43.14 Correct responses | Standard Deviation 2.88 |
| Post-test 3 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Caffeine | 42.74 Correct responses | Standard Deviation 3.03 |
| Post-test 3 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Placebo | 42.13 Correct responses | Standard Deviation 3.67 |
| Post-test 3 | Correct Responses on Serial 7 Subtraction Task | Subtract 7 Correct - Cocoa | 42.61 Correct responses | Standard Deviation 3.81 |
Comparison: Hypotheses were tested using a series (all outcome variables) of 2 Treatment x 4 Time point, repeated measures ANCOVAs that controlled for the prior night's sleep. Primary interests were the presence of statistically significant interactions of time and either cocoa versus placebo, cocoa + caffeine versus cocoa, or cocoa + caffeine versus caffeine-only. Significant interactions were decomposed using one-way ANOVAs and t-tests with familywise error controlled using LSD post-hoc tests.p-value: 0.05ANCOVA
Primary
Performance on Bakan Task
Performance on Bakan Task at baseline, post-test 1, post-test 2, and post-test 3 Bakan test presents numbers on a computer screen. Participant presses one button whenever the number 6 appears and a different button whenever three odd and different numbers in a row occurs such as 7 5 9. The number of times the participant does this correctly the better the performance. The scores range from 0 to 10 because the sequence of three odd and different numbers occurs a total of 10 times.
Time frame: baseline, post 60, post 90, post 120
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Pre-test | Performance on Bakan Task | Bakan Primary Correct - Caffeine + Cocoa | 5.83 units on a scale | Standard Deviation 1.59 |
| Pre-test | Performance on Bakan Task | Bakan Primary Correct - Caffeine | 6.35 units on a scale | Standard Deviation 1.5 |
| Pre-test | Performance on Bakan Task | Bakan Primary Correct - Placebo | 6.35 units on a scale | Standard Deviation 1.53 |
| Pre-test | Performance on Bakan Task | Bakan Primary Correct - Cocoa | 6.43 units on a scale | Standard Deviation 1.59 |
| Post-test 1 | Performance on Bakan Task | Bakan Primary Correct - Placebo | 6.00 units on a scale | Standard Deviation 1.57 |
| Post-test 1 | Performance on Bakan Task | Bakan Primary Correct - Caffeine + Cocoa | 6.13 units on a scale | Standard Deviation 1.77 |
| Post-test 1 | Performance on Bakan Task | Bakan Primary Correct - Cocoa | 6.52 units on a scale | Standard Deviation 1.44 |
| Post-test 1 | Performance on Bakan Task | Bakan Primary Correct - Caffeine | 6.57 units on a scale | Standard Deviation 1.78 |
| Post-test 2 | Performance on Bakan Task | Bakan Primary Correct - Placebo | 5.96 units on a scale | Standard Deviation 2.01 |
| Post-test 2 | Performance on Bakan Task | Bakan Primary Correct - Caffeine | 6.87 units on a scale | Standard Deviation 1.39 |
| Post-test 2 | Performance on Bakan Task | Bakan Primary Correct - Cocoa | 6.30 units on a scale | Standard Deviation 1.11 |
| Post-test 2 | Performance on Bakan Task | Bakan Primary Correct - Caffeine + Cocoa | 6.35 units on a scale | Standard Deviation 1.77 |
| Post-test 3 | Performance on Bakan Task | Bakan Primary Correct - Caffeine + Cocoa | 6.61 units on a scale | Standard Deviation 1.47 |
| Post-test 3 | Performance on Bakan Task | Bakan Primary Correct - Placebo | 6.09 units on a scale | Standard Deviation 1.95 |
| Post-test 3 | Performance on Bakan Task | Bakan Primary Correct - Caffeine | 6.13 units on a scale | Standard Deviation 1.36 |
| Post-test 3 | Performance on Bakan Task | Bakan Primary Correct - Cocoa | 5.78 units on a scale | Standard Deviation 1.7 |
Secondary
Vigor Symptoms (Profile of Mood State)
Vigor subscale scores from the Profile of Mood States.The higher the score the greater the feelings of energy. The scores range from a minimum of 0 to a maximum of 20.
Time frame: Pre and 90, 120 and 160 minutes post intervention
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Pre-test | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Placebo | 3.78 units on a scale | Standard Deviation 4.36 |
| Pre-test | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Caffeine | 3.91 units on a scale | Standard Deviation 3.66 |
| Pre-test | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Cocoa | 3.65 units on a scale | Standard Deviation 4.01 |
| Pre-test | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Caffeinated Cocoa | 4.09 units on a scale | Standard Deviation 4.43 |
| Post-test 1 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Caffeinated Cocoa | 4.48 units on a scale | Standard Deviation 4.28 |
| Post-test 1 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Cocoa | 3.74 units on a scale | Standard Deviation 3.45 |
| Post-test 1 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Caffeine | 3.91 units on a scale | Standard Deviation 3.99 |
| Post-test 1 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Placebo | 3.57 units on a scale | Standard Deviation 4 |
| Post-test 2 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Cocoa | 4.00 units on a scale | Standard Deviation 3.84 |
| Post-test 2 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Caffeinated Cocoa | 4.04 units on a scale | Standard Deviation 4.03 |
| Post-test 2 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Caffeine | 4.00 units on a scale | Standard Deviation 3.92 |
| Post-test 2 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Placebo | 3.52 units on a scale | Standard Deviation 3.44 |
| Post-test 3 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Caffeinated Cocoa | 4.17 units on a scale | Standard Deviation 3.87 |
| Post-test 3 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Placebo | 3.65 units on a scale | Standard Deviation 3.68 |
| Post-test 3 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Caffeine | 4.26 units on a scale | Standard Deviation 3.29 |
| Post-test 3 | Vigor Symptoms (Profile of Mood State) | POMS Vigor - Cocoa | 3.70 units on a scale | Standard Deviation 3.3 |