Coffee and what it does to your body - BBC World Service

May 16, 2024

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Coffee and what it does to your body

Ever wondered what coffee really does to your body? From Ethiopian goat herders to the Enlightenment, and from caffeine's effect on adenosine to safe daily limits, disc

Coffee has been consumed for at least 1,500 years. Approximately eight million cups are drunk worldwide during any given hour of viewing time, according to the source material's framing. The main active ingredient, caffeine, is considered the most widely consumed psychoactive drug in the world.

Origins

Coffee comes from the fruit of the Coffea arabica plant, which originated in Ethiopia.

One account attributes the discovery to a ninth-century goat herder named Kaldi. He observed that his goats had more energy after eating coffee berries and tried a bite himself. Historical records suggest that the Sufis of Yemen roasted the seed of the coffee berry, creating the beverage recognized today.

Historical Influence

In the 15th century, the first coffeehouses appeared across the Ottoman Empire. The practice spread to Europe in the following centuries. European coffeehouses became venues for discussing business, politics, and new ideas.

Jurgen Habermas, an academic, has argued that the Enlightenment may not have occurred without coffee. Some accounts go further and credit coffee with helping fuel the Enlightenment, a period that produced many of the ideas that underpin the modern world.

Philosophers including Kant and Voltaire questioned the Catholic Church's interpretation of the world. Voltaire is said to have drunk as many as 72 cups of coffee a day. Enlightenment thinkers turned to science and held that everything in the universe could be explained rationally. The Age of Enlightenment led to the overthrow of monarchs, the growth of democracy, and numerous scientific discoveries.

Economic and Social Impact

Coffee was also linked to the slave trade. The French used enslaved Africans on plantations in Haiti. By the early 1800s, Brazil was producing one third of the world's coffee using enslaved African labor.

Companies began providing coffee to workers and eventually allowed coffee breaks. The source material states that this was not an altruistic measure. Companies aimed to increase worker productivity.

Today, two billion cups of coffee are consumed every day. The global coffee industry is worth $90 billion a year. Coffee is also a fundamental social part of everyday life for billions of people.

Effects of Caffeine on the Body

Caffeine is absorbed from the digestive system through the intestine into the bloodstream. Its effects begin when it reaches the nervous system.

Caffeine has a chemical structure very similar to adenosine, a substance produced by the body. Caffeine binds to adenosine receptors on the surface of nerve cells, functioning like a key in a lock.

Adenosine slows the sympathetic nervous system. It reduces heart rate and produces drowsiness and relaxation. By blocking these receptors, caffeine produces the opposite effect:

Blood pressure may increase slightly, particularly in people who do not drink coffee often.
Brain activity increases. Caffeine stimulates the brain, suppresses hunger, and promotes alertness, which can extend concentration.
Mood may improve, and feelings of fatigue may be reduced.
Physical performance may improve. Many athletes use caffeine as a supplement.

The effects last between 15 minutes and two hours. The body removes caffeine within five to 10 hours of consumption, although residual effects can last longer.

To optimize the effects of caffeine, experts suggest abstaining from caffeine in the afternoon. This allows the cup of coffee the following morning to have greater impact.

Recommended Limits and Risks

For healthy adults, the recommended maximum intake is 400 milligrams of caffeine per day, equivalent to about four or five cups of coffee.

Exceeding this limit can cause:

Insomnia
Nervousness and anxiety
Tachycardia
Stomach discomfort and nausea
Headache

Toxic effects, including seizures, can result from rapid consumption of around 1,200 milligrams of caffeine, equivalent to about 12 cups of coffee.

Individual limits vary. Some people are genetically more sensitive to caffeine.

Health Associations

When consumed in moderation, coffee is associated with a reduced risk of:

Type 2 diabetes
Cardiovascular disease
Some cancers
Parkinson's disease

These benefits are not solely attributable to caffeine. Coffee contains other beneficial substances, including chlorogenic acid, a potent antioxidant that may reduce the risk of many diseases.

Introduction

Coffee is consumed worldwide at enormous scale and has a history of at least 1,500 years, with some claiming it helped fuel the Enlightenment. Its main active ingredient, caffeine, is considered the most widely consumed psychoactive drug.

Eight million cups of coffee are drunk worldwide during the video's runtime.
Coffee has been consumed for at least 1,500 years.
Some say coffee helped fuel the Enlightenment.
Caffeine is considered the most widely consumed psychoactive drug on the planet.

Origins of Coffee

Coffee comes from the fruit of the Coffea arabica plant, which originated in Ethiopia. Legends and historical records describe how it was discovered and first prepared as a beverage.

Coffee comes from the fruit of the Coffea arabica plant, which originated in Ethiopia.
A ninth century goat herder called Kaldi reportedly noticed his goats were more energetic after eating coffee berries.
Historic records suggest the Sufis of Yemen roasted the seed of the coffee berry to create the beverage known today.

Coffee Houses and Ideas

Coffee houses appeared across the Ottoman Empire in the 15th century and later spread to Europe, where they became places for discussing business, politics and new ideas.

The first coffee houses began to appear across the Ottoman Empire in the 15th century.
Coffee houses later spread to Europe in the following centuries.
European coffeehouses became spaces for discussing business, politics and new ideas.
Academic Jurgen Habermas says that without coffee we might not have had the Enlightenment.

The Age of Enlightenment

Enlightenment thinkers such as Kant and Voltaire, who reportedly drank as many as 72 cups a day, questioned Church interpretations and turned to science. The movement led to the overthrow of monarchs, the growth of democracy and scientific discoveries.

Philosophers Kant and Voltaire started to question the Catholic Church's interpretation of the world.
Voltaire is said to have drunk as many as 72 cups of coffee a day.
Enlightenment thinkers believed everything in the Universe could be rationally explained.
The Age of Enlightenment radically changed the world, leading to the overthrow of monarchs, the growth of democracy and numerous scientific discoveries.

Coffee and the Slave Trade

Coffee was tied to the slave trade. The French used enslaved Africans on plantations in Haiti, and by the early 1800s Brazil produced a third of the world's coffee using African slaves.

The French used slaves from Africa on plantations in Haiti.
By the early 1800s Brazil was producing a third of the world's coffee using African slaves.

Coffee, Capitalism and Work

Companies began giving coffee to workers and eventually introduced coffee breaks, a move aimed at increasing productivity rather than being altruistic. Coffee is now a major industry and social part of daily life.

Companies started giving coffee to their workers and eventually allowed coffee breaks.
The coffee breaks were intended to increase worker productivity and were not an altruistic move.
Two billion cups of coffee are consumed every day today.
Coffee is a $90 billion a year industry and a fundamental social part of everyday life for billions of people.

How Caffeine Affects the Body

Caffeine is absorbed into the bloodstream and acts on the nervous system by mimicking adenosine, binding to its receptors and blocking the calming effects of adenosine, which produces stimulation.

Caffeine is absorbed via the intestine into the bloodstream.
Effects begin when caffeine reaches the nervous system.
Caffeine has a chemical structure very similar to adenosine, a substance produced by the body.
Caffeine binds to adenosine receptors on the surface of nerve cells, like a key opening a lock.
Adenosine slows the sympathetic nervous system, reducing heart rate and producing drowsiness and relaxation.
By blocking adenosine receptors, caffeine produces the opposite effect.

Effects on the Brain and Performance

Caffeine raises blood pressure slightly, especially in those unaccustomed to coffee, stimulates the brain, suppresses hunger, improves alertness and concentration, and can boost mood and physical performance.

Blood pressure may increase slightly, especially in people not used to drinking coffee often.
Caffeine stimulates the brain, suppresses hunger and helps people stay alert and concentrate for longer.
Caffeine can have a positive impact on mood, inhibit fatigue and improve physical performance.
Many athletes use caffeine as a supplement.

Duration of Effects

The immediate effects of caffeine last 15 minutes to two hours, the body removes it within five to ten hours, and residual effects can last longer. Experts suggest avoiding caffeine in the afternoon to optimise its morning effect.

Effects of caffeine can last between 15 minutes and two hours.
The body removes caffeine five to 10 hours after consumption, but residual effects can last longer.
Experts suggest abstaining from caffeine in the afternoon so the following morning's coffee has more impact.

Safe Limits and Side Effects

For healthy adults the recommended maximum is 400 milligrams of caffeine a day, about four or five cups. Exceeding it causes side effects, and around 1,200 milligrams can be toxic. Sensitivity varies between people.

The recommended maximum for healthy adults is 400 milligrams of caffeine a day, about four or five cups of coffee.
Exceeding the limit can cause insomnia, nervousness, anxiety, tachycardia, stomach discomfort, nausea and headache.
Toxic effects such as seizures can be seen after rapid consumption of around 1,200 milligrams of caffeine, about 12 cups of coffee.
Some people are genetically more sensitive to caffeine, so limits vary from person to person.

Health Benefits

When drunk in moderation, coffee is associated with reduced risk of several diseases. Beneficial substances beyond caffeine, such as chlorogenic acid, may also contribute to these health gains.

Coffee in moderation is associated with a reduced risk for type 2 diabetes, cardiovascular disease, some cancers and Parkinson's.
These health gains are not just linked to caffeine.
Coffee contains chlorogenic acid, a potent antioxidant that may reduce the risk of many diseases.