Caffeine works quickly and stimulates – that’s well known. But how exactly caffeine works in the body and what side effects there are, most people don’t even know. We’ll show you what coffee, cola and co. do to the body.
Caffeine and its effects on the body
Caffeine takes effect after just 30 minutes and is distributed throughout the body via the blood. The effects of caffeine last about four hours:
High doses of caffeine make the heart beat faster and increase the pulse. Blood pressure also rises in people who rarely consume caffeine.
Even in small doses, caffeine can improve concentration and temporarily eliminate tiredness.
Caffeine also often constricts the blood vessels in the brain and can thus relieve mild headaches and migraines.
The muscles can be better supplied with oxygen when we consume caffeine. That’s why some athletes take caffeine before training, for example in the form of tablets.
However, our body gets used to caffeine with regular consumption. This habituation effect leads to the fact that many of the mentioned modes of action occur only weakly or not at all.
side effects of caffeine
Consuming too much caffeine can result in a caffeine overdose. Doctors speak of an overdose of one gram of caffeine. This corresponds to 15 to 20 cups of espresso. Symptoms include:
sleep disorders
restlessness
headache
nervousness
Panic Attacks
Gastrointestinal complaints
circulatory collapse
Some of the symptoms don’t even require an overdose—they can occur with overconsumption. However, this is usually harmless because of the said habituation effect, so that many people can tolerate several cups of coffee in a row.
According to the European Food Safety Authority, 200 mg of caffeine per single dose and 400 mg per day are safe for humans. Children should consume a maximum of 3 mg of caffeine per kilogram of body weight.
Caffeine content in coffee, cola & co.
The amount of caffeine in coffee depends on many factors: How hot was the coffee roasted and brewed, how long does it steep, how finely are the beans ground and which beans are they? A guide value can still be set for coffee and other caffeinated foods:
Coffee: 50 mg per 100 ml
Espresso: 130 mg per 100 ml
Black and green tea: 20 mg per 100 ml
Coca-Cola: 10mg/100ml
Club Mate: 20 mg / 100 ml
Red Bull: 32mg/100ml
Dark chocolate: 90 mg / 100 g
Milk chocolate: 15 mg / 100 g
A cup with 250 ml of coffee comes to around 125 mg of caffeine.
However, the amount of caffeine can vary greatly, especially in restaurants and cafés with professional coffee machines: In the USA, scientists have found large differences in the amount of caffeine when comparing espresso in different restaurants. In their study, the researchers found up to 317 mg of caffeine per espresso – more than the maximum single dose should contain according to the EU.
Caffeine for hair loss?
Many shampoos now contain caffeine, which according to advertising is said to protect against hair loss. However, its effectiveness is controversial because there is no clear scientific evidence for it. Caffeinated shampoos can stimulate cell growth, but the specific effect is unclear. In any case, you don’t have to buy such a product – you can instead make your own shampoo for your hair out of old coffee grounds.
Are caffeine pills harmful?
Caffeine tablets work just like the caffeine in coffee and tea. However, it is highly concentrated and can be taken at any time. A caffeine tablet usually contains 200 mg of caffeine and thus the maximum single dose.
For many people, caffeine tablets are better tolerated than coffee. Because the acid contained in coffee can lead to stomach problems.
However, the high dosage should only be taken if you are already used to caffeine. Otherwise symptoms such as restlessness, nervousness and sleep disorders can quickly occur.
Like other caffeinated foods, caffeine pills can only mask tiredness. The effect of the tablets abruptly wears off over time. Therefore, you should not use them as a pick-me-up when driving.
