By the time you finish watching this video, 8 million cups of coffee will have been drunk all over the world.当你看完这个视频时，世界各地将已经喝掉800万杯咖啡。Coffee has been consumed for at least one and a half thousand years, and some say its impact is so great that it help fuel the Enlightenment,咖啡已经被消费了至少1500年，有人说它的影响如此之大，以至于它有助于推动启蒙运动，which gave rise to some of the big ideas that underpin the world as we know it.这引发了一些支撑我们所知世界的伟大想法。The main active ingredient of coffee is caffeine, which is considered the most widely consumed psychoactive drug on the planet.咖啡的主要活性成分是咖啡因，它被认为是地球上使用最广泛的精神活性药物。So where does coffee come from, and what does it do to us when we drink it?那么咖啡从哪里来？当我们喝它时它对我们有什么影响呢？Coffee comes from the fruit of the coffee aerobic plant that originated in Ethiopia.咖啡来自原产于埃塞俄比亚的咖啡有氧植物的果实。One story claims a 9th century goat herder called Caldy saw his goats were more full of energy after eating coffee berries, so he had a bite too.有一个故事称，9世纪一位名叫考迪的牧羊人发现他的山羊在吃了咖啡浆果后更加充满活力，所以他也咬了一口。Historic records suggest the Sufis of Yemen roasted the seed of the coffee berry to create the beverage we recognize today.历史记录表明，也门苏菲派烘烤咖啡浆果的种子，创造了我们今天所认识的饮料。In the 15th century, the 1st coffee houses began to appear across the Ottoman Empire before spreading to Europe in the following centuries,15世纪，第一个咖啡馆开始出现在奥斯曼帝国各地，然后在接下来的几个世纪里传播到欧洲，coffee houses in Europe became a space for discussing business, politics and new ideas.欧洲的咖啡馆成为讨论商业、政治和新思想的空间。One academic, Yogen Habermass even says, without coffee, we might not have had the Enlightenment.一位学者约根·哈伯马斯甚至说，如果没有咖啡，我们可能就不会有启蒙运动。Philosophers like cant and Voltaire, who is said to have drunk as many as 72 cups a day,坎特和伏尔泰等哲学家，据说伏尔泰每天喝多达72杯酒，started to question the Catholic church's interpretation of the world.开始质疑天主教会对世界的解释。Instead, they looked to science, believing that everything in the universe could be rationally explained.相反，他们转向科学，相信宇宙中的一切都可以合理解释。This so called age of Enlightenment radically changed the world as we knew it.这个所谓的启蒙时代从根本上改变了我们所知道的世界。It led to the overthrow of monarchs, the growth of democracy and numerous scientific discoveries.它导致了君主的推翻、民主的发展和众多科学发现。Coffee also fueled the slave trade.咖啡也助长了奴隶贸易。The French used slaves from Africa on plantations in Haiti.法国人在海地的种植园使用来自非洲的奴隶。and by the early 1800 hundreds Brazil was producing a 3rd of the world's coffee using African slaves.到了18--年初，巴西利用非洲奴隶生产了世界第三的咖啡。Did coffee give rise to capitalism too?.Companies started giving away coffee to their workers and eventually let them have coffee breaks.咖啡也催生了资本主义吗？公司开始向员工赠送咖啡，并最终让他们有喝咖啡的休息时间。This wasn't an altruistic move.这不是一个无私的举动。They were trying to increase worker productivity.他们试图提高工人的生产力。Fast forward to the present, and 2 billion cups of coffee are consumed every day.快进到现在，每天消耗20亿杯咖啡。It's a $90 billion a year industry.这是一个每年价值900亿美元的行业。And more than that, it is a fundamental social part of everyday life for billions of people.更重要的是，它是数十亿人日常生活的基本社会部分。So how does coffee impact the body?那么咖啡如何影响身体呢？When caffeine enters your digestive system, it's absorbed by the intestine into the bloodstream.当咖啡因进入消化系统时，它会被肠道吸收进入血液。But the effects only start when caffeine hits the nervous system.但只有当咖啡因影响神经系统时，这种影响才会开始。This happens because caffeine has a chemical structure very similar to that of an substance produced by our own body, adenosine.发生这种情况是因为咖啡因的化学结构与我们自己身体产生的物质腺苷非常相似。Caffeine binds to the bodies adenosine receptors, which can be found on the surface of nerve cells.咖啡因与体内的腺苷受体结合，该受体可以在神经细胞表面找到。It's like a key opening a lock.这就像一把钥匙打开锁。Adenosine is known to slow down the sympathetic nervous system.众所周知，腺苷可以减慢交感神经系统的速度。It reduces your heart rate and generates a state of drowsiness and relaxation.它会降低你的心率并产生嗜睡和放松的状态。By blocking these receptors, caffeine generates the opposite effect.通过阻断这些受体，咖啡因会产生相反的效果。Your blood pressure, for example, may increase slightly, especially if you are not used to drinking coffee.例如，您的血压可能会略有升高，特别是如果您不习惯喝咖啡。Often the same goes for brain activity.大脑活动通常也是如此。Caffeine stimulates the brain, suppresses hunger and helps you stay in the state of alertness so you can concentrate for longer.咖啡因可以刺激大脑，抑制饥饿，帮助您保持警觉状态，以便您可以更长时间地集中注意力。Caffeine can have a positive impact on your mood, inhibit feelings of fatigue, and can improve physical performance,咖啡因可以对你的情绪产生积极影响，抑制疲劳感，并可以改善身体表现，so many athletes use it as a supplement.很多运动员都将其作为补充剂。These effects can last between 15 min and 2 h The body removes caffeine five to 10 h after consuming,这些作用可持续15分钟至2小时摄入咖啡因后5至10小时，身体会清除咖啡因，but caffeine's residual effects can last even longer.但咖啡因的残余作用可以持续更长时间。If you want to optimize caffeine's effects on your body, experts suggest abstaining from caffeine in the afternoon,如果您想优化咖啡因对身体的影响，专家建议下午戒掉咖啡因，so your cup of coffee the following morning has more impact. Coffee also requires care when it's drunk.所以第二天早上你的一杯咖啡会产生更大的影响。喝咖啡时也需要小心。For healthy adults, the recommended maximum limit is 400 mg of caffeine a day.对于健康成年人来说，建议的最高摄入量为每天400毫克咖啡因。That's about four or five cups of coffee.大约四五杯咖啡。Exceeding this limit can lead to side effects such as insomnia, nervousness, anxiety, tachycardia, stomach discomfort, nausea and headache.超过这个限度可能会导致副作用，例如失眠、紧张、焦虑、心动过速、胃部不适、恶心和头痛。Toxic effects like seizures can be seen after the rapid consumption of around 1200 mg of caffeine.快速服用1200毫克左右后，可以看到癫痫等毒性作用。That's the equivalent of around twelve cups of coffee.这相当于大约十二杯咖啡。Of course, these limits vary from person to person.当然，这些限制因人而异。Some people are genetically more sensitive to caffeine, but when drunk in moderation, coffee can be good for your health.有些人从基因上对咖啡因更敏感，但适量饮用咖啡对健康有益。For instance, is associated with a reduced risk for type two diabetes, cardiovascular disease, some cancers and Parkinson.例如，与降低患二型糖尿病、心血管疾病、某些癌症和帕金森病的风险有关。And these health gains aren't just linked to cafe.这些健康益处不仅仅与咖啡馆有关。Coffee has other beneficial substances, such as chlorogenic acid, a poaching antioxidant that may reduce the risk of the many diseases.咖啡还含有其他有益物质，例如氯喹，这是一种偷猎抗氧化剂，可以降低许多疾病的风险。So next time you grab a cup of coffee, you might not look at it the same again.所以下次你喝一杯咖啡时，你可能会再次看到同样的东西。