Coffee contains caffeine. You know it, I know it, it's common knowledge. It's also one of its greatest appeals!
For many of us, this love started in school: long study nights required a boost, as did early morning classes. Now, our daily dose is an integral part of an invigorating morning routine or a little mid-afternoon treat.
Knowing that 90% of North Americans consume it regularly, it's time to understand this craze.
With this guide, you'll be fully equipped to answer Trivial Pursuit questions and finally beat that relative who thinks they're a genius!
What exactly is caffeine?
Caffeine is an odorless alkaloid. It is a natural ingredient found in green coffee beans. It is also found in many other plants:
- Tea
- Cocoa
- Kola nut
- Guarana
- Yerba mate
It is also used as a food additive in soft drinks and in certain over-the-counter medications (cough, cold, and pain remedies).
Wait... is caffeine a drug?
Yes! Caffeine is the most widely consumed psychoactive stimulant by humans, as it speeds up the central nervous system. It is a legal psychoactive substance and, in most countries, unregulated.
Don't panic, though: the FDA classifies it as a GRAS (generally recognized as safe) substance. The usual dose is well below the toxic dose, which is around 1 gram for an adult. By comparison, a cup of filtered coffee contains on average only 120 mg of caffeine.
How does it affect our bodies?
Caffeine stimulates our central nervous system, but we are not all equal in its effects. Tolerance varies from person to person.
- Positive effects: For some, a small amount improves mood, increases alertness, and boosts concentration.
- Negative effects: For more sensitive individuals, it can cause insomnia, headaches, irritability, or nervousness.
- Hidden benefits: Recent international studies show that moderate caffeine consumption has protective effects against Parkinson's and Alzheimer's diseases.
The myth of dehydration
It is often said that coffee is a diuretic. This is true, but mild. Caffeine causes a temporary elimination of water through urine. However, regular consumption creates tolerance, and this effect quickly fades.
The Journey of Caffeine: From Sip to Blood
From your very first sip, the process begins:
- Absorption: Caffeine enters the bloodstream through the mucous membranes of the mouth, throat, and stomach.
- Timing: It takes up to 45 minutes for most of the caffeine to be fully absorbed.
- Duration: Its stimulating effects can last up to 3 hours.
Note: The contents of your stomach (whether you are fasting or not) directly influence the speed and intensity of these effects.
How much caffeine is in your cup?
Caffeine is water-soluble, which is why brewing extracts it. The bean variety plays a major role: 100% Arabica beans naturally contain less caffeine than Robusta.
If we scientifically break down a cup of brewed coffee, the numbers are surprising:
- 98.6% of your cup is water.
- 1.4% of the volume represents dissolved coffee residues.
- Of this 1.4% coffee, only 1.2% is caffeine.
Ultimately, your cup of coffee contains on average only 0.0168% pure caffeine. An infinitesimal amount, but amply sufficient to give us the energy needed to face the day!
