The effect of guarana versus caffeine on fat oxidation in healthy college students
Corrine A., Christine C., Veronica G., Jacqueline J., Lauren M., Emily S., & Tim W.
Guarana (Paullinia Cupana)
Traditionally used as a tonic for: Heat fatigue Migraine Diarrhea Hypertension Currently used as a supplement for: Stamina General stimulant
Guaranine = Caffeine
Guaranine / Guarana Caffeine / Coffee Theine / Tea contains 5-10% naturally occurring caffeine guaranine is modified by other components of guarana
contains : threophylline & theobromine guarana is rich in seed fiber, tannins and saponins These compounds are said to be released slowly over 6 hours Guarana toxic at doses @ 10 grams
to the synergistic effect of guarana’s main constituents, we speculate that an equivalent dose of guaranine will fat oxidation for a longer amount of time than caffeine
To determine if supplementation with guarana will increase fat oxidation for a greater amount of time than caffeine in healthy inviduals in a resting state.
clinical trial Crossover design 6 subjects (1 male & 5 females) Similar breakfast consumed before study RER measured w/ Metabolic Cart Baseline RER measured
mg capsule of guarana (90 mg caffeine) 200 mg No Doz split in half (~90 mg caffeine) RER measured every hour for 5 hours No food or drink (except water) Mean and standard deviation calculated
The mean RER of Guarana and Caffeine during 5 hours of rest
Hour Baseline 1 2 3 4 5 Mean 0.87 0.83 0.81 0.79 0.74 0.74 St Dev. 0.036 0.049 0.034 0.047 0.033 0.020
Mean 0.89 0.84 0.80 0.77 0.76 0.76 St Dev. 0.096 0.076 0.061 0.040 0.048 0.062
The effect of guarana vs caffeine on RER over time
1 0.9 0.8 0.7 0.6 RER 0.5 0.4 0.3 0.2 0.1 0 0 1 2 3 4 5 Time (hours)
out of the 6 subjects demonstrated the expected results, although to only a small degree Insufficient evidence to conclude that guarana encourages fat metabolism for a longer time than caffeine No difference between guarana & caffeine OR poor study design?
sample size Subjects not blinded Study not long enough Food as a confounder
– dinner the night before
– breakfast – fast
caffeine from decaf coffee
of guarana capsule Additives in No Doz Menstrual cycle as possible confounder Differences in lean body mass Habitual caffeine use Movie induced giggling / stress
large difference between guarana and caffeine was not observed A more controlled trial could provide more reliable results More time required to observe trends