Effects of Theobromine and Caffeine on Mood and Vigilance.
ABSTRACT Like caffeine, theobromine crosses the blood-brain barrier and binds to adenosine receptors, suggesting it might share caffeine's beneficial effects on mood and vigilance. Therefore, the purpose of this study was to assess the effect of theobromine doses commonly found in foods on mood and vigilance parameters sensitive to caffeine. Caffeine was tested as a positive control. Twenty-four men (age, 23  years) completed 6 double-blind trials during which they consumed experimental beverages, assessed their mood using standardized self-report questionnaires, and completed a 2-hour visual vigilance task. Three experimental doses (100, 200, and 400 mg theobromine) were delivered in a cocoa-based beverage; 3 matched control treatments (0 mg theobromine, 400 mg theobromine, and 100 mg caffeine) were delivered in a non-cocoa beverage. Mean salivary concentrations of theobromine exhibited significant dose-dependent differences (400 mg trials > 200 mg trial > 100 mg trial > 0 mg trials; P < 0.005). At every dose tested, theobromine failed to consistently affect mood state or vigilance (P > 0.05), but 100-mg caffeine significantly decreased lethargy/fatigue and increased vigor (P = 0.006 and 0.011, respectively). These findings indicate theobromine does not influence mood and vigilance when administered in nutritionally relevant doses, despite sharing many of caffeine's structural characteristics.
- SourceAvailable from: nih.govBritish Journal of Clinical Pharmacology 03/1979; 7(2):U57-63. · 3.58 Impact Factor
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ABSTRACT: In order to assess the subjective effects of nefopam, a new non-opiate analgesic, a study was designed using highly educated, young, middle-to-upper class subjects in a naturalistic setting. Results suggest that the design is capable of differentiating variations in subjective drug effects. On a number of measures, 10 mg of d-amphetamine, a modest dosage, could be distinguished from placebo, showing changes in the direction expected for stimulant drugs. Nefopam (90 mg), on the other hand, showed few differences from placebo or caffeine (300 mg). Nefopam appeared mildly dysphoric, rather than stimulant, in subjective effects.Clinical Pharmacology & Therapeutics 09/1978; 24(2):243-52. · 6.85 Impact Factor
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ABSTRACT: Twenty-five minutes after ingesting one of three possible dosages (placebo, 200 mg, or 400 mg) of caffeine, 48 subjects individually participated in two short-term visual target scanning tasks (subject-paced and experimenter-paced). Assignment of subjects to treatment groups was made on the basis of a priori coffee consumption rates. Subjects who reported that they normally consumed less than three cups of coffee per week (average) were assigned to the low usage rate group (LR), while those who reported average consumption rates of three cups or more per week were assigned to the high usage rate group (HR). Latencies were obtained for the subject-paced measure by allowing subjects to scan ten 10 × 10 matrices until the target was found. Correct detection percentages were taken for the experimenter-paced task by allowing subjects to scan ten 10 × 10 matrices for 5 s and report whether or not a pre-announced target number was contained in the matrix. Significant differences in latencies were obtained between LR and HR only with 400 mg caffeine dosages. LR exhibited significantly higher latencies as a function of these dosages than did HR. No reliable differences occurred between LR and HR for correct detection percentages.Human Factors The Journal of the Human Factors and Ergonomics Society 03/1978; 20(1):91-6. · 1.18 Impact Factor