Venti.Banish ban·ish tr.v. ban·ished, ban·ish·ing, ban·ish·es 1. To force to leave a country or place by official decree; exile. 2. To drive away; expel: We banished all our doubts and fears. your venti-sized coffee cup. Harvard scientists have found that ingesting tiny doses of caffeine caffeine (kăfēn`), odorless, slightly bitter alkaloid found in coffee, tea, kola nuts (see cola), ilex plants (the source of the Latin American drink maté), and, in small amounts, in cocoa (see cacao). (chemical found in coffee) throughout the day keeps you more alert than having one huge, a.m. java jolt. Why? Consider how caffeine works: As you burn energy to perform daily activities, your body cells produce adenosine adenosine /aden·o·sine/ (ah-den´o-sen) a purine nucleoside consisting of adenine and ribose; a component of RNA. It is also a cardiac depressant and vasodilator used as an antiarrhythmic and as an adjunct in myocardial perfusion imaging . This chemical binds to special receptors on the cell surface, signaling you to feel sleepy. Caffeine tricks your body into feeling alert because its molecules (particles of two or more atoms, the smallest units of an element, joined together) are similar in structure to adenosine molecules. They fit into the cell receptors, too. With caffeine in the way, adenosine can't deliver its need-for-sleep message. But caffeine exits the bloodstream blood·stream n. The flow of blood through the circulatory system of an organism. bloodstream the blood flowing through the circulatory system in the living body. as the day progresses. So the jolt you get from a giant morning coffee dwindles fast. Instead, participants in the Harvard study ingested in·gest tr.v. in·gest·ed, in·gest·ing, in·gests 1. To take into the body by the mouth for digestion or absorption. See Synonyms at eat. 2. a small dose of caffeine every hour, with the equivalent of one eight-ounce coffee lasting a person an entire day. The result: constant pick-me-ups throughout the day. This dosage strategy may help people like firefighters, who need to stay awake during emergencies. But Tom Scammell, a neurologist Neurologist A doctor who specializes in disorders of the brain and central nervous system. Mentioned in: Cervical Disk Disease neurologist a specialist in neurology. (brain scientist) at Harvard, warns that it isn't a sleep substitute. "Not sleeping is like not paying off a loan. The debt is still there, and the amount of sleep you owe keeps growing." Charles Czeisler, a biologist who worked on the study, adds that cheating on sleep spells big trouble for teens. Teens need 9 to 10 hours of sleep per day for healthy development. If you feel tired, Czeisler says, your body is telling you to hit the pillow--not the caffeine. Did You Know? * In huge doses, caffeine is lethal. Scientists calculated the deadly dose at more than 10 grams. That's equivalent to drinking 80 to 100 cups of coffee in one sitting. * Believe it or not, coffee is second to oil as the most-valuable commodity in the world. The United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. imports approximately one sixth of the world's yearly crop. * Finland is home to the world's record coffee drinkers. The average Finn drinks approximately 1,400 cups per year. Resources * Learn more about the Harvard Medical School Harvard Medical School (HMS) is one of the graduate schools of Harvard University. It is a prestigious American medical school located in the Longwood Medical Area of the Mission Hill neighborhood of Boston, Massachusetts. caffeine-dosage study at: www.news.harvard.edulgazettel20041 05.13/12-caffeine.html * For great information on caffeine, check out the Center for Science in the Public Interest's Caffeine: The Inside Scoop: www.cspinet.org/nah/caffeine.htm |
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