Full transcript
0:00By the time you finish watching this video,
0:02eight million cups of coffee will have been drunk all over the world.
0:07Coffee has been consumed for at least
0:101,500 years and some say its impact is so great that it helped fuel
0:16the Enlightenment, which gave rise to some of the
0:18big ideas that underpin the world as we know it. The main active ingredient of coffee is
0:25caffeine, which is considered the most widely consumed psychoactive drug on the planet.
0:33So where does coffee come from and
0:35what does it do to us when we drink it? Coffee comes from the fruit of the
0:41Coffea arabica plant that originated in Ethiopia. One story claims a ninth Century goat
0:48herder called Kaldi, saw his goats were more full of energy after eating coffee berries —
0:53so he had a bite too. Historic records suggest the Sufis of Yemen
0:59roasted the seed of the coffee berry to create the beverage we recognise today.
1:07In the 15th Century, the first coffee houses
1:09began to appear across the Ottoman Empire before spreading to Europe in the
1:14following centuries. Coffeehouses in Europe became a
1:17space for discussing business, politics and new ideas.
1:22One academic - Jurgen Habermas – even says without coffee we might
1:26not have had the Enlightenment.
1:30Philosophers like Kant and Voltaire - who is said to have drunk as many as 72 cups a
1:36day - started to question the Catholic Church’s interpretation of the world.
1:42Instead they looked to science, believing that everything in the Universe could
1:46be rationally explained. This so-called Age of Enlightenment
1:51radically changed the world as we knew it. It led to the overthrow of monarchs, the
1:57growth of democracy, and numerous scientific discoveries.
2:02Coffee also fuelled the slave trade. The French used slaves from Africa on
2:08plantations in Haiti and by the early 1800s Brazil was producing a third of the world’s
2:15coffee using African slaves.
2:23Did coffee give rise to capitalism too?
2:26Companies started giving away coffee to their workers and eventually let
2:31them have coffee breaks. This wasn’t an altruistic move.
2:35They were trying to increase worker productivity.
2:40Fast forward to the present and two billion cups of coffee are consumed every day.
2:51It’s a $90 billion a year industry. And, more than that, it is a
2:55fundamental social part of everyday life for
2:58billions of people.
3:01So how does coffee impact the body?
3:07When caffeine enters your digestive system, it is absorbed via the intestine into the
3:11bloodstream. But the effects only start when caffeine
3:15hits the nervous system. This happens because caffeine has a
3:19chemical structure very similar to that of a substance produced by our own body:
3:24adenosine. Caffeine binds to the body’s adenosine
3:30receptors, which can be found on the surface of nerve cells.
3:37It's like a key opening a lock. Adenosine is known to slow down the
3:42sympathetic nervous system - it reduces your heart rate and generates a state of drowsiness
3:48and relaxation. By blocking these receptors, caffeine
3:53generates the opposite effect. Your blood pressure, for example, may
3:58increase slightly, especially if you are not used to drinking coffee often.
4:03The same goes for brain activity: caffeine stimulates the brain,
4:07suppresses hunger and helps you stay in a state of alertness, so you
4:11can concentrate for longer. Caffeine can have a positive impact on
4:16your mood, inhibit feelings of fatigue, and can improve physical performance.
4:22So, many athletes use it as a supplement.
4:24These effects can last between 15 minutes and two hours.
4:28The body removes caffeine five to 10 hours after consuming it but caffeine’s residual
4:33effects can last even longer.
4:40If you want to optimise caffeine's
4:43effects on your body, experts suggest abstaining from caffeine in the afternoon
4:47- so your cup of coffee the following morning has more impact.
4:54Coffee also requires care when it’s drunk.
4:57For healthy adults, the recommended [maximum] limit is 400 milligrams of caffeine a day.
5:01That’s about four or five cups of coffee.
5:05Exceeding this limit can lead to side effects such as insomnia, nervousness, anxiety,
5:11tachycardia, stomach discomfort, nausea and headache.
5:17Toxic effects, like seizures, can be seen after the rapid consumption of around
5:231,200 milligrams of caffeine - that’s the equivalent of around 12 cups of coffee.
5:27Of course these limits vary from person
5:31to person: some people are genetically more
5:34sensitive to caffeine. But when drunk in moderation, coffee
5:38can be good for your health. For instance, it’s associated with a
5:43reduced risk for type 2 diabetes, cardiovascular disease, some cancers and Parkinson’s.
5:50And these health gains aren't just
5:52linked to caffeine. Coffee has other beneficial substances,
5:56such as chlorogenic acid, a potent antioxidant that may reduce the risk of many diseases.
6:02So next time you grab a cup of coffee, you might not look at it the same again.