User:Syeda Anum/sandbox

Introduction:
Caffeine, an adenosine antagonist, is a bitter alkaloid that is a central nervous system stimulant[1,2]. Also known as Guaranine or 1, 3, 7-trimethylxanthine, it was discovered in 1820 by a German chemist Friedlieb Ferdinand Runge. Caffeine is found in many food and beverages including coffee, tea, soft drinks, and energy drinks.

Caffeine is widely consumed throughout the world in which 43% of the population uses tea while 54% use coffee [3]. Netherlands, Norway, and Sweden have the highest rate of caffeine consumption from coffee and the UK leads in tea consumption [3]. In North America, it is estimated that over 80% of the population uses caffeine daily [4].

Many over the counter medicine such as NoDoz and Vivarin also contain about 100-200 mg of caffeine per tablet [5].A low caffeine intake is about 130-300 mg/day, while heavy coffee ingestion corresponds to over 6000 mg/day [6]. Overuse of caffeine is common among college students because it can restore alertness and increase concentration. These effects can last over three hours but caffeine can also lead to tolerance and withdrawal. Caffeine is considered to be an addictive drug that follows the same mechanism as amphetamines, cocaine, and heroin to stimulate the brain [7]. Caffeine can affect the mood, stamina, cerebral vascular activity, and colonic activity.

History:
Although the exact date of the first use of caffeine is unknown, Chinese legend believes that emperor Shen Nung discovered tea around 2737 BCE [8]. Coffee beans were discovered in Ethiopia in 850 AD. During the same period, tea became the national beverage in China [8]. Around1400-1500 AD, caffeine spread throughout Africa and the Middle East and was introduced to America in the 1700s in the form of tea. Today, in the 21st century, coffee is the world’s popular beverage and is consumed by about 90% of the population.

Pharmacology:
Caffeine affects the psychological state of people who consume it. It is a habit forming drug that depends on the dose of caffeine [9]. At a moderate level, caffeine can induce pleasant effects but high dose can cause agitation, anxiety, and apnea [9].

Caffeine in moderation
Moderate caffeine consumption can increase alertness, reduce fatigue, boost energy, increase attention and reaction time [10].It can also improve performance while carrying out tasks such as driving. These positive effects have caused people, especially students, to rely on caffeine while studying and during moments of low energy. Although its reaction is unclear, caffeine in coffee is linked to a decrease risk in developing Parkinson’s disease and dementia [11].

Caffeine in energy drinks
Caffeine, a key ingredient, is present in large contents in energy drinks. The overuse of these beverages can cause hypertension and increase respiratory rate [1,4,12]. Cases associated with caffeine poisoning show common symptoms of tachycardia, hypertension, nausea, dizziness, heart palpitation, jolt and crash episodes, and headaches [12,13]. These symptoms vary with caffeine dose and can have different effects on men and women. Caffeinated drinks have become a problem among college students who use it for insufficient sleep, lack of energy, studying, driving, and in combination with alcohol.

Caffeine and Taurine
In combination with other key ingredients of energy drinks such as taurine, caffeine can enhance side effects. The specific combination of caffeine and taurine has been linked to an increase in arterial blood pressure and a decrease in heart rate [1].

Caffeine’s effect on alcohol
Caffeinated energy drinks have become popular among youth who believe that its combination with alcohol minimizes intoxication and reduces hangovers [14,15]. Caffeine’s effect on alcohol depends on the blood alcohol level. At low levels, caffeine can mitigate the impairment from alcohol but at high blood alcohol level, physical and mental damages can not be altered. Combining energy drinks with alcohol can cause an increase in episodic drinking and weekly drunkenness [12]. They are also linked to higher blood pressure, higher lactate, and noradrenaline levels [2]. Energy drinks in combination with alcohol increase the risk of cardiac arrhythmias in people who are already at risk [16]. Recent news have attempted to exploit the danger of caffeinated-alcohol containing energy drinks such as Four Loko. Also referred as black out in a can or liquid cocaine, Four Loko contains 12% alcohol which is about five or six cans of beer. Nine students from Central Washington University were hospitalized after drinking the beverage in addition to 23 students in New Jersey [17]. Universities have taken action to prevent students from consuming Four Loko and Michigan has banned the product.

Caffeinated drinks and fitness activity
Athletes, striving for enhanced performance, consume caffeinated energy drinks during strenuous physical training. Although moderate amount is considered safe, overuse of energy drinks is linked to an increase stroke volume and diastolic inflow velocity which can be seen 40 minutes after work out [18]. Many tragedies have occurred in which victims have suffered from cardiac arrest after consuming caffeine [12,16]. One such case includes a healthy 18 year old Irish basketball player who consumed four cans of Red Bull prior to a game [19].

Caffeine as a diuretic
Caffeine is a diuretic that promotes dehydration. Because it is present in energy drinks, it does not replace fluid loss from physical activity [16]. This effect can reduce performance; approximately 4% of dehydration equals 20% performance lost [19].

Psychological effects
High levels of caffeine, approximately 300 mg, are linked to poor motor performance and insomnia [9]. The symptoms of caffeine are similar to those found in anxiety neurosis which includes irritability, twitching, and nervousness [9]. The excessive intake of caffeine is also related to mental illness in psychiatric patients [9].

Refrences
1. Bichler A, Swenson A, Harris MA: A combination of caffeine and Taurine has not effect on short term memory but induces changes in heart rate and mean arterial blood pressure. Amino Acids 2006, 31:471-476. 2. Curry K, Stasio M. The effects of energy drinks alone and with alcohol on neuropsychological functioning. Human Psychopharmacology: Clinical & Experimental. August 2009;24(6):473-481. 3. Gilbert RM. Caffeine Consumption. Progress in Clinical and Biological Research.1984;(158):185-213. 4.James JE. Critical review of dietary caffeine and blood pressure: a relationship that should be taken more seriously. Psychosom Med. 2004, 66(1): 63-71. 5.Caffeine dependence. Information about caffeine dependence. [Internet]. C. 2003. [Cited 2010 Nov7]. Avaible from: http://www.caffeinedependence.org 6.Kovacs B. Caffeine.[internet]. c .2010. [cited 2010 Nov 7]. Available from: http://www.medicinenet.com. 7.Fredholm BB, Bättig K, Holmén J, Nehlig A, Zvartau EE. Actions of caffeine in the brain with special reference to factors that contribute to its widespread use. Pharmacol Rev. 1999; 51(1):83-133. 8.MyAddiction Caffeine timeline [Internet]. Online addiction and recovery resource: c2010[cited 2010 Nov7]. Available from:http://www.myaddiction.com/education/articles/caffeine_timeline.html 9.Bolton, S. Caffeine: Psychological Effects, Use and Abuse. Orthomolecular Psychiatry 10 (3): 202–211. 10.Smith A. Effects of caffeine on human behavior. Food and Chemical Toxicology. 2002; 40 (9):1243-1255. 11.Osterweil N. Cofee and Your Health.[internet] 2010 Sept. 28. [cited: 2010 Nov. 7]. Available from: www.webmd.com 12.Reissig CJ, Strain EC , Griffiths RR. Caffeinated Energy Drinks—a growing problem. Drug and Alcohol Dependence 2009; 99(1-3):1-10. 13.Malinauskas, Brenda M. Aeby G. Victor, Overton F. Reginald. Carpenter-Aeby, Tracy. Barber-Heidel, Kimberly. A survey of energy drink consumption patterns among college students. Nutritional Journal 2007 6(35). 14.Arria, M. Amelia, Caldeira M. Kimberly, Kasperski J. Sarah, Grady E. Kevin, Vincent B. Kathryn, Griffiths R. Roland,Wish D. Eric. Increased Alcohol Consumption, nonmedical prescription drug use, and illicit Drug use are associated with Energy drink consumption among college students. J Addict Med 2010; (4):74-80. 15.Weldy L. David. Risks of Alcoholic Energy Drinks for Youth. J Am Board Fam Med 2010; 23:555-558. 16.Duchan E, Patel ND, Feucht C. Energy drinks: a review of use and safety for athletes. Phys Sportsmed. 2010 Jun; 38(2):171-9. 17.Broom, Jack. AG wants to ban drink that hospitalized CWU students.[internet]. 2010 Oct 26.[cited 2010 Nov.7].Available from: http://www.seattletimes.com. 18.Baum M., Weiss M. The influence of a Taurine of a Taurine containing drink on cardiac parameters before and after exercise measured by echocardiography.Amino Acids 2001, 20: 75-82). 19.Paddock R. Energy drinks’ effects on student-athletes and implications for athletic department. United States sports academy. 11(4).