This report from the Committee on Military Nutrition Research reviews the history of caffeine usage, the metabolism of caffeine, and its physiological effects. The effects of caffeine on physical performance, cognitive function and alertness, and alleviation of sleep deprivation impairments are discussed in light of recent scientific literature. The impact of caffeine consumption on various aspects of health, including cardiovascular disease, reproduction, bone mineral density, and fluid homeostasis are reviewed. The behavioral effects of caffeine are also discussed, including the effect of caffeine on reaction to stress, withdrawal effects, and detrimental effects of high intakes. The amounts of caffeine found to enhance vigilance and reaction time consistently are reviewed and recommendations are made with respect to amounts of caffeine appropriate for maintaining alertness of military personnel during field operations. Recommendations are also provided on the need for appropriate labeling of caffeine-containing supplements, and education of military personnel on the use of these supplements. A brief review of some alternatives to caffeine is also provided.

Contents

• THE NATIONAL ACADEMIES
• COMMITTEE ON MILITARY NUTRITION RESEARCH
• FOOD AND NUTRITION BOARD
• Dedication
• Reviewers
• Preface
• Executive Summary
• 1. Basic Concepts
  • MILITARY INTEREST IN CAFFEINE
  • HISTORY OF CAFFEINE USE
  • THE COMMITTEE'S TASK
• 2. Pharmacology of Caffeine
  • ABSORPTION, DISTRIBUTION, AND METABOLISM
  • FACTORS AFFECTING CAFFEINE METABOLISM
  • PHYSIOLOGICAL EFFECTS
  • SUMMARY
• 3. Efficacy of Caffeine
  • PHYSICAL PERFORMANCE
  • COGNITIVE FUNCTION AND ALERTNESS
  • COMPENSATION OF SLEEP DEPRIVATION IMPAIRMENTS
  • SUMMARY
• 4. Safety of Caffeine Usage
  • CAFFEINE AND CARDIOVASCULAR DISEASE RISK
  • CAFFEINE EFFECTS ON REPRODUCTION
  • CAFFEINE EFFECTS ON BONE MINERAL DENSITY
  • CAFFEINE EFFECTS ON FLUID HOMEOSTASIS
  • DETRIMENTAL EFFECTS OF HIGH DOSES OF CAFFEINE
  • SUMMARY
• 5. Doses and Delivery Mechanisms
  • OPTIMUM CAFFEINE DOSAGE
  • CAFFEINE DELIVERY MECHANISMS
  • SUMMARY
• 6. Special Considerations
  • EDUCATION AND TRAINING ISSUES
  • LABELING
  • ETHICAL CONSIDERATIONS
  • ALTERNATIVES TO CAFFEINE FOR MAINTENANCE OF COGNITIVE PERFORMANCE
  • SUMMARY
• 7. Response to Military Questions, Conclusions, and Recommendations
  • Conclusions
  • Recommendations
  • Hypertension
  • Cardiovascular Disease
  • Reproduction
  • Fluid Homeostasis
  • Behavioral Effects
  • Physical Dependence and Withdrawal
  • Caffeine and Stress
  • Conclusions
  • Recommendations
  • Conclusions
  • Recommendations
  • Combination of Caffeine and Naps
  • Amphetamine
  • Modafinil
  • Conclusions
  • Recommendations
  • Conclusions
  • Recommendations
  • ADDITIONAL RESEARCH RECOMMENDATIONS
• References
• Appendixes
  • A Workshop Agenda and Abstracts
  • B Previous Recommendations on Caffeine from the Committee on Military Nutrition Research
  • C Biographical Sketches

Support for this project was provided by the U.S. Department of the Army, Army Medical Research and Materiel Command through grant No. DAMD17– 94-J-4046 and grant No. DAMD17–99–1–9478. The U.S. Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick, MD 21702– 5014, is the awarding and administering acquisition office. The views presented in this publication are those of the Committee on Military Nutrition Research and do not necessarily reflect the position or policy of the government, and no official endorsement should be inferred.

NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.