A start into the day without a hot cup of coffee is unimaginable for many people. The caffeine contained in the coffee gets our circulation going and has a positive effect on our mood. On average, every German consumes about 200 milligrams of caffeine per day - in addition to coffee, the intake of tea, cola, energy drinks and chocolate. Since caffeine has a stimulating effect, a cup of coffee or a glass of cola helps us to overcome small power downs. But caffeine can - especially if too much of it is consumed - also have side effects.
Effect of caffeine
Caffeine takes between 30 and 45 minutes to enter the bloodstream. It is distributed through the body before it is finally eliminated with the urine. The half-life of caffeine in the body is around four hours. In individuals who are slowing down caffeine removal, such as in pregnant women, the half-life may increase up to 20 hours.
Caffeine has a broad spectrum of activity: In low doses, it has a stimulating effect on the psyche - it improves concentration and eliminates signs of tiredness. In addition, the storage capacity of the brain is also increased. Thus, caffeine can have a positive effect on the learning performance in examination phases in the short term.
Caffeine also has an increased effect on the cardiovascular system. By taking caffeine, the heart beats more frequently and more vigorously, increasing the heart rate and blood pressure. However, the blood pressure increase is minimal and occurs especially in people who are not used to caffeine.
Caffeine and sports
Caffeine also has an effect on the blood vessels: While the blood vessels in the periphery widen, the vessels narrow in the brain - so caffeine can have a soothing effect on headaches or migraines. This is why caffeine is now included in some headache tablets in addition to the painkillers.
Peripheral vessel expansion also suggests a positive effect of caffeine on our athletic performance, as the muscles can be better supplied with oxygen. In addition, the increased activity of the heart and the expansion of the bronchi by caffeine can also have a positive effect on our performance.
The mechanism of action of caffeine
Many people take caffeine - whether it be in the form of coffee, energy drinks or caffeine tablets - to increase their attention. The positive effect of caffeine on our attention and focus is due to the fact that caffeine in our body interferes with certain processes.
When our nerve cells are active, they consume energy, producing adenosine as a by-product. The more the nerve cells work, the more adenosine is released. It ensures that the nerve cells in our brains do not overstrain. This happens because adenosine activates certain receptors that are responsible for the conduction. When the receptors are activated, the information is relayed more slowly from nerve cell to nerve cell.
Caffeine has a similar structure to adenosine and can thereby dock at the same receptors. However, it only occupies the receptors without activating them. As a result, no signal is sent to the nerve cells for slower work - so the nerve cells continue to work at full speed.
By consuming caffeine regularly, however, the body gets used to the substance and the effect of caffeine on attention and concentration diminishes. This is due to the fact that over time, the body forms more adenosine receptors and thus can re-dock the molecule to some free receptors. In order to achieve a performance-enhancing effect again, the caffeine intake would have to be increased more and more.
Caffeine: side effects and withdrawal symptoms
If caffeine is consumed in large quantities, it can lead to a number of side effects. These include sleep disorders, headaches, nervousness or gastrointestinal discomfort. Likewise, the consumption of caffeine may result in a loss of fine motor skills. Those who regularly consume caffeine, however, rarely suffers from the described side effects, as already a habituation effect has occurred.
Anyone who regularly delivers caffeine in high doses to his body for a long period of time can become addicted to caffeine. Whether you suffer from caffeine addiction, you can easily test yourself: If there is a decrease in caffeine consumption to withdrawal symptoms, you are addicted. The symptoms of withdrawal may include headache and nausea, but also energy loss and drowsiness. In addition, influences on the mood must be expected: A loss of motivation and drive, but also depression-like states and irritability are typical withdrawal symptoms. They last about 12 to 24 hours after the last caffeine intake and can last up to nine days.
An overdose of caffeine is said to be greater than one gram of caffeine. Such a dose can result in a greatly accelerated pulse and extrasystoles. In addition, it can lead to restlessness and insomnia. Some people may also experience anxiety due to excessive caffeine intake. In the worst case, an overdose of caffeine can cause a circulatory collapse.