Coffee is one of the world's most significant beverages, consumed globally at a rate of two billion cups daily. Its history spans over 1,500 years, beginning with its origins in Ethiopia and its development as a drink by Sufis in Yemen. The spread of coffeehouses across the Ottoman Empire and later Europe created hubs for intellectual exchange, with some historians arguing that coffee helped fuel the Enlightenment by providing a space for philosophers and new ideas.

However, coffee's history is also marked by exploitation, as its global cultivation fueled the slave trade on plantations in Haiti and Brazil. In the modern era, it became intertwined with capitalism, as companies provided coffee to boost worker productivity.

The primary active ingredient, caffeine, is a psychoactive stimulant. It works by blocking adenosine receptors in the nervous system, which counters drowsiness and increases alertness, heart rate, and concentration. These effects can last for hours and are used by athletes to enhance performance.

While moderate consumption (up to 400mg of caffeine, or about 4-5 cups daily) is linked to health benefits like reduced risks of type 2 diabetes and Parkinson's, excessive intake can cause anxiety, insomnia, and more severe toxic effects. The benefits are attributed not only to caffeine but also to antioxidants like chlorogenic acid.

Ultimately, coffee is more than a drink—it’s a $90 billion-a-year industry and a fundamental social ritual that has profoundly shaped history, economics, and daily life.

By the time you finish watching this video, eight million cups of coffee will have been drunk all over the world.

Coffee has been consumed for at least 1,500 years, and some say its impact is so great that it helped fuel the Enlightenment—which gave rise to some of the big ideas that underpin the world as we know it. The main active ingredient of coffee is caffeine, which is considered the most widely consumed psychoactive drug on the planet.

So where does coffee come from and what does it do to us when we drink it?

Coffee comes from the fruit of the Coffea arabica plant that originated in Ethiopia. One story claims that a ninth-century goat herder called Kaldi saw his goats were more full of energy after eating coffee berries—so he had a bite too. Historic records suggest the Sufis of Yemen roasted the seed of the coffee berry to create the beverage we recognize today.

In the 15th century, the first coffeehouses began to appear across the Ottoman Empire before spreading to Europe in the following centuries. Coffeehouses in Europe became a space for discussing business, politics, and new ideas. One academic, Jürgen Habermas, even says that without coffee we might not have had the Enlightenment.

Philosophers like Kant and Voltaire—who is said to have drunk as many as 72 cups a day—began to question the Catholic Church’s interpretation of the world. Instead, they looked to science, believing that everything in the universe could be rationally explained. This so-called Age of Enlightenment radically changed the world as we knew it. It led to the overthrow of monarchs, the growth of democracy, and numerous scientific discoveries.

Coffee also fueled the slave trade. The French used slaves from Africa on plantations in Haiti, and by the early 1800s Brazil was producing a third of the world’s coffee using African slaves.

Did coffee give rise to capitalism too? Companies started giving away coffee to their workers and eventually let them have coffee breaks. This wasn’t an altruistic move—they were trying to increase worker productivity.

Fast-forward to the present, and two billion cups of coffee are consumed every day. It’s a $90 billion-a-year industry. And, more than that, it is a fundamental social part of everyday life for billions of people.

So how does coffee impact the body?

When caffeine enters your digestive system, it is absorbed via the intestine into the bloodstream. But the effects only start when caffeine hits the nervous system. This happens because caffeine has a chemical structure very similar to that of a substance produced by our own body: adenosine. Caffeine binds to the body’s adenosine receptors, which can be found on the surface of nerve cells—it’s like a key opening a lock.

Adenosine is known to slow down the sympathetic nervous system; it reduces your heart rate and generates a state of drowsiness and relaxation. By blocking these receptors, caffeine generates the opposite effect. Your blood pressure, for example, may increase slightly, especially if you are not used to drinking coffee often.

The same goes for brain activity: caffeine stimulates the brain, suppresses hunger, and helps you stay in a state of alertness so you can concentrate for longer. Caffeine can have a positive impact on your mood, inhibit feelings of fatigue, and can improve physical performance—so many athletes use it as a supplement.

These effects can last between 15 minutes and two hours. The body removes caffeine five to 10 hours after consuming it, but caffeine’s residual effects can last even longer.

If you want to optimize caffeine's effects on your body, experts suggest abstaining from caffeine in the afternoon so your cup of coffee the following morning has more impact.

Coffee also requires care when it’s drunk. For healthy adults, the recommended maximum limit is 400 milligrams of caffeine a day—that’s about four or five cups of coffee. Exceeding this limit can lead to side effects such as insomnia, nervousness, anxiety, tachycardia, stomach discomfort, nausea, and headache. Toxic effects, like seizures, can be seen after the rapid consumption of around 1,200 milligrams of caffeine—the equivalent of around 12 cups of coffee.

Of course, these limits vary from person to person: some people are genetically more sensitive to caffeine. But when drunk in moderation, coffee can be good for your health. For instance, it’s associated with a reduced risk for type 2 diabetes, cardiovascular disease, some cancers, and Parkinson’s. And these health gains aren't just linked to caffeine. Coffee has other beneficial substances, such as chlorogenic acid, a potent antioxidant that may reduce the risk of many diseases.

So next time you grab a cup of coffee, you might not look at it the same again.

BBC News: Coffee & What It Does To Your Body

bbc-news-coffee-what-it-does-to-your-body

Let's do English ESL general vocabulary practice. Coffee is one of the world's most significant beverages, consumed globally at a rate of two billion cups daily…