How does caffeine keep us awake? - Hanan Qasim
View full lesson: http://ed.ted.com/lessons/how-does-caffeine-keep-us-awake-hanan-qasim Over 100000 metric tons of caffeine are consumed around the world every year. That's equivalent to...
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Over 100,000 metric tons of caffeine are consumed around the world every year. That's equivalent to the weight of 14 Eiffel Towers. Most of this caffeine is consumed in coffee and tea, but it's also ingested in some sodas, chocolate, caffeine pills, and even beverages labeled decaf. Caffeine helps us feel alert, focused, happy, and energetic, even if we haven't had enough sleep. But it can also raise our blood pressure, and make us feel anxious. It's the world most widely used drug. So how does it keep us awake? Caffeine evolved in plants where it serves a few purposes. In high doses, as it's found in the leaves and seeds of certain species, it's toxic to insects. But when they consume it in lower doses, as it's found in necta...
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Over 100,000 metric tons of caffeine are consumed around the world every year. That's equivalent to the weight of 14 Eiffel Towers. Most of this caffeine is consumed in coffee and tea, but it's also ingested in some sodas, chocolate, caffeine pills, and even beverages labeled decaf. Caffeine helps us feel alert, focused, happy, and energetic, even if we haven't had enough sleep. But it can also raise our blood pressure, and make us feel anxious. It's the world most widely used drug. So how does it keep us awake? Caffeine evolved in plants where it serves a few purposes. In high doses, as it's found in the leaves and seeds of certain species, it's toxic to insects. But when they consume it in lower doses, as it's found in necta...
