Caffeine-Not just a stimulant.

OBJECTIVE The beneficial effects of human caffeine consumption deserve clarification. METHODS A detailed literature review was conducted and summarized. RESULTS A large body of scientific evidence describes the beneficial effects of human caffeine consumption on a number of physiologic systems. CONCLUSION The consumption of moderate amounts of caffeine 1) increases energy availability, 2) increases daily energy expenditure, 3) decreases fatigue, 4) decreases the sense of effort associated with physical activity, 5) enhances physical performance, 6) enhances motor performance, 7) enhances cognitive performance, 8) increases alertness, wakefulness, and feelings of "energy," 9) decreases mental fatigue, 10) quickens reactions, 11) increases the accuracy of reactions, 12) increases the ability to concentrate and focus attention, 13) enhances short-term memory, 14) increases the ability to solve problems requiring reasoning, 15) increases the ability to make correct decisions, 16) enhances cognitive functioning capabilities and neuromuscular coordination, and 17) in otherwise healthy non-pregnant adults is safe.

[1]  D. Hunter,et al.  Coffee, tea, caffeine and risk of breast cancer: A 22‐year follow‐up , 2008, International journal of cancer.

[2]  A. Steptoe,et al.  Association between coffee consumption and markers of inflammation and cardiovascular function during mental stress , 2006, Journal of hypertension.

[3]  T. Balkin,et al.  Effects of dextroamphetamine, caffeine and modafinil on psychomotor vigilance test performance after 44 h of continuous wakefulness , 2008, Journal of sleep research.

[4]  Andrew P. Smith,et al.  Effects of repeated doses of caffeine on mood and performance of alert and fatigued volunteers , 2005, Journal of psychopharmacology.

[5]  B. Shukitt-Hale,et al.  Effects of caffeine, sleep loss, and stress on cognitive performance and mood during U.S. Navy SEAL training , 2002, Psychopharmacology.

[6]  T. Burns,et al.  Maternal caffeine consumption and risk of neural tube defects. , 2009, Birth defects research. Part A, Clinical and molecular teratology.

[7]  J. Lane,et al.  Effects of hot tea, coffee and water ingestion on physiological responses and mood: the role of caffeine, water and beverage type , 1997, Psychopharmacology.

[8]  Andrew P. Smith Caffeine, cognitive failures and health in a non‐working community sample , 2009, Human psychopharmacology.

[9]  P. Rogers,et al.  Cognitive and psychomotor performance, mood, and pressor effects of caffeine after 4, 6 and 8 h caffeine abstinence , 2005, Psychopharmacology.

[10]  F. Hu,et al.  Coffee consumption and markers of inflammation and endothelial dysfunction in healthy and diabetic women. , 2006, The American journal of clinical nutrition.

[11]  Frank Hu,et al.  The Relationship of Coffee Consumption with Mortality , 2008, Annals of Internal Medicine.

[12]  B. Dawson,et al.  Influence of caffeine ingestion on perceived mood states, concentration, and arousal levels during a 75-min university lecture. , 2007, Advances in physiology education.

[13]  F. Hu,et al.  Coffee Consumption and Risk of Stroke in Women , 2009, Circulation.

[14]  Andrew P. Smith,et al.  Effects of caffeine in non‐withdrawn volunteers , 2005, Human psychopharmacology.

[15]  J. Greenberg,et al.  Caffeinated coffee consumption, cardiovascular disease, and heart valve disease in the elderly (from the Framingham Study). , 2008, The American journal of cardiology.

[16]  S. Mondillo,et al.  Acute effects of caffeine and cigarette smoking on ventricular long-axis function in healthy subjects , 2008, Cardiovascular ultrasound.

[17]  J. Baron,et al.  Metabolic and hormonal effects of caffeine: randomized, double-blind, placebo-controlled crossover trial. , 2007, Metabolism: clinical and experimental.

[18]  A. Reunanen,et al.  Prospective study of coffee consumption and risk of Parkinson's disease , 2008, European Journal of Clinical Nutrition.

[19]  Thomas J Balkin,et al.  Sustaining executive functions during sleep deprivation: A comparison of caffeine, dextroamphetamine, and modafinil. , 2009, Sleep.

[20]  J D Gabrieli,et al.  Caffeine's Effects on Performance and Mood are Independent of Age and Gender. , 1998, Nutritional neuroscience.

[21]  Pierre Philip,et al.  The Effects of Coffee and Napping on Nighttime Highway Driving , 2006, Annals of Internal Medicine.

[22]  P. Barberger‐Gateau,et al.  The neuroprotective effects of caffeine , 2007, Neurology.

[23]  M. Feinglos,et al.  Exaggeration of postprandial hyperglycemia in patients with type 2 diabetes by administration of caffeine in coffee. , 2007, Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists.

[24]  K. Anderson,et al.  Coffee and caffeine intake and the risk of ovarian cancer: the Iowa Women’s Health Study , 2008, Cancer Causes & Control.

[25]  J. Geleijnse Habitual coffee consumption and blood pressure: An epidemiological perspective , 2008, Vascular health and risk management.

[26]  Andrew P. Smith,et al.  Effects of repeated doses of caffeine on performance and alertness: new data and secondary analyses , 2007, Human psychopharmacology.

[27]  W. Willett,et al.  Coffee consumption and risk of incident gout in men: a prospective study. , 2007, Arthritis and rheumatism.

[28]  S. Toubro,et al.  The effect of caffeine, green tea and tyrosine on thermogenesis and energy intake , 2009, European Journal of Clinical Nutrition.

[29]  S. Hernández-Díaz,et al.  Transient Exposure to Coffee as a Trigger of a First Nonfatal Myocardial Infarction , 2006, Epidemiology.

[30]  J. Manson,et al.  Coffee Consumption and Coronary Heart Disease in Men and Women: A Prospective Cohort Study , 2006, Circulation.

[31]  Alan R. Kristal,et al.  Coffee, Tea, Colas, and Risk of Epithelial Ovarian Cancer , 2008, Cancer Epidemiology Biomarkers & Prevention.

[32]  N. Taub,et al.  Maternal caffeine intake during pregnancy and risk of fetal growth restriction: a large prospective observational study , 2008, BMJ : British Medical Journal.

[33]  H. Lieberman,et al.  The Effects of Caffeine and Aspirin on Mood and Performance , 1987, Journal of clinical psychopharmacology.

[34]  Drew Dawson,et al.  Perception of simulated driving performance after sleep restriction and caffeine. , 2007, Journal of psychosomatic research.

[35]  M. Schiff,et al.  Coffee consumption and the risk of gestational diabetes mellitus , 2007, Acta obstetricia et gynecologica Scandinavica.

[36]  F. Tsofliou,et al.  Influence of caffeine on perception of effort, metabolism and exercise performance following a high-fat meal , 2006, Journal of sports sciences.

[37]  R. Dahl,et al.  Caffeine consumption, sleep, and affect in the natural environments of depressed youth and healthy controls. , 2007, Journal of pediatric psychology.

[38]  I Biaggioni,et al.  Caffeine and theophylline as adenosine receptor antagonists in humans. , 1991, The Journal of pharmacology and experimental therapeutics.

[39]  K. Kendler,et al.  Caffeine intake, toxicity and dependence and lifetime risk for psychiatric and substance use disorders: an epidemiologic and co-twin control analysis , 2006, Psychological Medicine.

[40]  Caffeinated coffee consumption and mortality after acute myocardial infarction. , 2004 .

[41]  R. Freire,et al.  Panic disorder and social anxiety disorder subtypes in a caffeine challenge test , 2009, Psychiatry Research.

[42]  R. Herning,et al.  Caffeine withdrawal, acute effects, tolerance, and absence of net beneficial effects of chronic administration: cerebral blood flow velocity, quantitative EEG, and subjective effects , 2009, Psychopharmacology.

[43]  L. Stovner,et al.  High dietary caffeine consumption is associated with a modest increase in headache prevalence: results from the Head-HUNT Study , 2009, The Journal of Headache and Pain.

[44]  L. Andersen,et al.  Consumption of coffee is associated with reduced risk of death attributed to inflammatory and cardiovascular diseases in the Iowa Women's Health Study. , 2006, The American journal of clinical nutrition.

[45]  E Cafarelli,et al.  Effects of caffeine on neuromuscular function. , 1999, Journal of applied physiology.

[46]  G. Belenky,et al.  Caffeine maintains vigilance and marksmanship in simulated urban operations with sleep deprivation. , 2005, Aviation, space, and environmental medicine.

[47]  H. Lieberman,et al.  The effects of low doses of caffeine on human performance and mood , 2004, Psychopharmacology.

[48]  D. Gertig,et al.  Caffeine, alcohol, smoking, and the risk of incident epithelial ovarian cancer , 2008, Cancer.

[49]  A. Attwood,et al.  Differential responsiveness to caffeine and perceived effects of caffeine in moderate and high regular caffeine consumers , 2007, Psychopharmacology.

[50]  R. Cohen,et al.  Maternal smoking, alcohol consumption, and caffeine consumption during pregnancy in relation to a son's risk of persistent cryptorchidism: a prospective study in the Child Health and Development Studies cohort, 1959-1967. , 2008, American journal of epidemiology.

[51]  H. Lieberman Cognitive methods for assessing mental energy , 2007, Nutritional neuroscience.

[52]  H. Soininen,et al.  Midlife coffee and tea drinking and the risk of late-life dementia: a population-based CAIDE study. , 2009, Journal of Alzheimer's disease : JAD.

[53]  L. Robinson,et al.  Glucose homeostasis remains altered by acute caffeine ingestion following 2 weeks of daily caffeine consumption in previously non-caffeine-consuming males , 2007, British Journal of Nutrition.

[54]  K. Funatsu,et al.  Effect of Coffee Intake on Blood Pressure in Male Habitual Alcohol Drinkers , 2005, Hypertension Research.

[55]  C. Vlachopoulos,et al.  Effect of chronic coffee consumption on aortic stiffness and wave reflections in hypertensive patients , 2007, European Journal of Clinical Nutrition.

[56]  H. Luukinen,et al.  Coffee consumption and mortality in a 14-year follow-up of an elderly northern Finnish population , 2008, British Journal of Nutrition.

[57]  Barbara Shukitt-Hale,et al.  Caffeine effects on marksmanship during high-stress military training with 72 hour sleep deprivation. , 2003, Aviation, space, and environmental medicine.

[58]  P. Whelton,et al.  The effect of chronic coffee drinking on blood pressure: a meta-analysis of controlled clinical trials. , 1999, Hypertension.

[59]  D. Panagiotakos,et al.  Chronic coffee consumption has a detrimental effect on aortic stiffness and wave reflections. , 2005, The American journal of clinical nutrition.

[60]  W. Willett,et al.  Recurrence of pre-eclampsia across generations: exploring fetal and maternal genetic components in a population based cohort , 2005, BMJ : British Medical Journal.

[61]  T. Balkin,et al.  Caffeine effects on recovery sleep following 27 h total sleep deprivation. , 2005, Aviation, space, and environmental medicine.

[62]  D. Kennedy,et al.  Cognitive and mood improvements of caffeine in habitual consumers and habitual non-consumers of caffeine , 2005, Psychopharmacology.

[63]  Satoru Hayasaka,et al.  The effect of daily caffeine use on cerebral blood flow: How much caffeine can we tolerate? , 2009, Human brain mapping.

[64]  Thomas J Balkin,et al.  Caffeine effects on risky decision making after 75 hours of sleep deprivation. , 2007, Aviation, space, and environmental medicine.

[65]  F. Hu,et al.  Coffee Consumption Is Associated With Higher Plasma Adiponectin Concentrations in Women With or Without Type 2 Diabetes , 2008, Diabetes Care.

[66]  C. Kawas,et al.  Non-alcoholic beverage and caffeine consumption and mortality: the Leisure World Cohort Study. , 2007, Preventive medicine.

[67]  K. Chayama,et al.  Effects of acute administration of caffeine on vascular function. , 2006, The American journal of cardiology.

[68]  M. Hamer,et al.  Coffee and health: explaining conflicting results in hypertension , 2006, Journal of Human Hypertension.

[69]  M. Kennedy,et al.  The cumulative effect of coffee and a mental stress task on heart rate, blood pressure, and mental alertness is similar in caffeine-naïve and caffeine-habituated females. , 2008, Nutrition research.

[70]  J. Carrier,et al.  Effects of Caffeine are more Marked on Daytime Recovery Sleep than on Nocturnal Sleep , 2007, Neuropsychopharmacology.

[71]  S. McClaran,et al.  Low doses of caffeine reduce heart rate during submaximal cycle ergometry , 2007, Journal of the International Society of Sports Nutrition.

[72]  F. Sofi,et al.  Coffee consumption and risk of coronary heart disease: a meta-analysis. , 2007, Nutrition, metabolism, and cardiovascular diseases : NMCD.

[73]  Stefan Golaszewski,et al.  Does caffeine modulate verbal working memory processes? An fMRI study , 2008, NeuroImage.

[74]  E. Hogervorst,et al.  Caffeine improves physical and cognitive performance during exhaustive exercise. , 2008, Medicine and science in sports and exercise.

[75]  D. Grobbee,et al.  Blood pressure response to chronic intake of coffee and caffeine: a meta-analysis of randomized controlled trials , 2005, Journal of hypertension.

[76]  Justin R. Bland,et al.  Effects of different doses of caffeine on exercise responses in young children. , 2008, Medicine & Science in Sports & Exercise.

[77]  F. Hu,et al.  Dietary patterns and risk of nonfatal acute myocardial infarction in Costa Rican adults , 2006, European Journal of Clinical Nutrition.

[78]  E. Cafarelli,et al.  Effect of caffeine on self‐sustained firing in human motor units , 2002, The Journal of physiology.

[79]  F. Hu,et al.  Coffee consumption and risk of cardiovascular events and all-cause mortality among women with type 2 diabetes , 2009, Diabetologia.

[80]  D. Kennedy,et al.  Cognitive and physiological effects of an “energy drink”: an evaluation of the whole drink and of glucose, caffeine and herbal flavouring fractions , 2004, Psychopharmacology.

[81]  Lee Ryan,et al.  Caffeine attenuates practice effects in word stem completion as measured by fMRI BOLD signal , 2007, Human brain mapping.

[82]  J. Vinson,et al.  Coffee and cardiovascular disease: in vitro, cellular, animal, and human studies. , 2007, Pharmacological research.

[83]  W. Willett,et al.  Caffeine consumption and the risk of primary open-angle glaucoma: a prospective cohort study. , 2008, Investigative ophthalmology & visual science.

[84]  M. S. Ganio,et al.  Caffeine, Fluid-Electrolyte Balance, Temperature Regulation, and Exercise-Heat Tolerance , 2007, Exercise and sport sciences reviews.

[85]  De-kun Li,et al.  Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study. , 2008, American journal of obstetrics and gynecology.

[86]  Frank Hu,et al.  Coffee Consumption and Risk for Type 2 Diabetes Mellitus , 2004, Annals of Internal Medicine.

[87]  E. Feskens,et al.  Coffee intake and incidence of hypertension. , 2007, The American journal of clinical nutrition.

[88]  A. Nobre,et al.  The effects of combined caffeine and glucose drinks on attention in the human brain , 2005, Nutritional neuroscience.

[89]  E. Ravussin,et al.  Reduced sympathetic nervous activity. A potential mechanism predisposing to body weight gain. , 1993, The Journal of clinical investigation.

[90]  I. Hindmarch,et al.  A naturalistic investigation of the effects of day-long consumption of tea, coffee and water on alertness, sleep onset and sleep quality , 2000, Psychopharmacology.

[91]  Y. Teo,et al.  Association between caffeine intake and risk of Parkinson's disease among fast and slow metabolizers , 2007, Pharmacogenetics and genomics.

[92]  A. Dulloo,et al.  Green tea and thermogenesis: interactions between catechin-polyphenols, caffeine and sympathetic activity , 2000, International Journal of Obesity.

[93]  B. Dworetzky,et al.  A prospective study of smoking, caffeine, and alcohol as risk factors for seizures or epilepsy in young adult women: Data from the Nurses’ Health Study II , 2010, Epilepsia.

[94]  Thomas J Balkin,et al.  Restoration of risk-propensity during sleep deprivation: caffeine, dextroamphetamine, and modafinil. , 2008, Aviation, space, and environmental medicine.