Too much caffeine can cause dizziness

Caffeine: Recommended amount, effects and side effects

Caffeine: Popular pick-me-up

Caffeine is part of everyday life for most adults and is very popular. The per capita consumption of coffee beans in Germany is now 65 kilograms per year, reports the International Coffee Organization (ICO). Caffeine is not only found in coffee and cola, but also, for example, in black or green tea (here it is often called Teein) or cocoa. For many, it's not just about the taste, but about the activating caffeine effect. Caffeine is supposed to wake you up - and it does.

What is caffeine

Basically, caffeine is a psychoactive substance, an alkaloid that occurs naturally in various plants. Caffeine serves the plants as a defense against pests. It is contained, for example, in:

  • Seeds of the guarana tree
  • Coffee beans
  • Cocoa pods
  • Nuts of the cola
  • Leaves of tea bushes and mate plants

In humans, caffeine, which can also be produced synthetically, has a stimulating effect on the nervous system and increases concentration. This works with small amounts of around 100 milligrams, i.e. about one cup of filter coffee. In this country, the brown bean stock is the main source of caffeine for adults (proportion of total intake: 85 percent).

Caffeine: effect

Caffeine works by stimulating the release of the stress hormones cortisol and adrenaline. This increases blood pressure and makes the heart beat faster. 15 to 30 minutes are enough for the caffeine to get into the bloodstream and take effect. Degradation and elimination from the body in the urine then take an average of four hours.

How strongly someone reacts to the substance depends, on the one hand, on how regularly they consume it. You can get used to caffeine, the awakening effect then subsides. On the other hand, it is also crucial how sensitively someone reacts to caffeine and how quickly or slowly the metabolism pushes the stimulant out again.

Caffeine: what are the positive effects?

The most famous effect of this substance is that it helps to stay or wake up. It does this by docking onto the so-called adenosine receptors in the nerve tissue and blocking them. The messenger substance adenosine regulates brain activity and functions as a tiredness signal.

A dose of 100 to 600 milligrams of caffeine also speeds up thinking, increases body coordination and relaxes the bronchi.

In addition, caffeine constricts the blood vessels, including those of the head arteries (which widen during a migraine attack), and the sensation of pain is reduced. For this reason, and because it increases the concentration of transmitter substances (e.g. serotinin, dopamine) in the brain, it is also recommended as a remedy for migraines and headaches.

For coffee itself, there is evidence that it may protect against type 2 diabetes, Parkinson's, depression, and liver disease. The consumption of coffee is also said to support cognitive abilities in old age. In addition to caffeine, other substances contained in coffee are probably responsible for these effects, for example antioxidants.

Caffeine: side effects

Too much caffeine can have exactly the negative effect and trigger migraines and headache attacks in the first place. Other possible side effects are:

  • increased need to urinate
  • Incontinence (in men)
  • Stomach discomfort (increased stomach acid production)
  • Problems falling asleep, insomnia
  • inner restlessness up to states of anxiety
  • Sweats
  • Arrhythmia
  • nervousness
  • irritability

Safe consumption of caffeine per day

These symptoms are possible from a dose of 5.3 mg / kg body weight caffeine. But that is not yet an overdose. For healthy adults, single doses of up to 200 milligrams (i.e. about 3 mg / kg body weight) and daily rations of up to 400 milligrams (5.7 mg / kg body weight) are considered safe. For orientation: One cup of filter coffee (200 ml) contains around 90 milligrams of caffeine.

It becomes harmful if children and sick people (for example with cardiac arrhythmias) ingest too much of it - even in combination with some medications (for example thyroid medication), little or no caffeine should be consumed. Otherwise it can lead to cardiovascular problems. For children and adolescents, the following limits apply to tea, cocoa and chocolate, depending on their age: 0.2 (3-10 years) to 1.4 (10-18 years) milligrams per kilogram of body weight and day.

Pregnant women also have to keep an eye on their caffeine consumption, because caffeine penetrates the placenta unhindered. Because caffeine can influence the growth of the fetus because it does not yet have any enzymes that break down the caffeine. According to the European Food Safety Authority, expectant mothers therefore recommend not drinking more than 200 milligrams (approx. Two cups of coffee) per day.

Athletes should also be careful with the stimulant - at least during exercise. It is no longer on the list of prohibited substances. However, it shouldn't be more than one to two milligrams of caffeine per kilogram of body weight in competition and training, otherwise dizziness and a racing heart are threatened, especially if you are not used to caffeine.

Special case energy drinks and energy shots

Energy drinks, i.e. caffeinated drinks that often also contain taurine, glucuronolactone and / or inositol, and energy shots, the more concentrated brothers of drinks, are popular pick-me-ups among young people, at work and for the party night.

If such an overall very high amount of caffeine is consumed, side effects can occur. However, moderate consumption of energy drinks (pay attention to consumption and consumer instructions) is considered harmless. After all, a can (250 ml) only contains around 80 milligrams of caffeine - a little less than a cup of coffee (200 ml).

Caffeine: table of different foods

To keep track of your consumption, it is good to know how much caffeine is in which foods. There are also lists from specialist bodies such as the European Food Safety Authority (EFSA).

Caffeine: withdrawal symptoms

Caffeine is part of everyday life for many people - their bodies are used to the daily dose. This can go so far that withdrawal is accompanied by withdrawal symptoms that are also known from other addictive substances. Possible complaints are tiredness, exhaustion, nausea and, above all, headaches. The cause of the headache is an increased speed of the blood flow in the brain after stopping the caffeine. So if you want to reduce your consumption, you should caffeine it is better to gradually taper off or, if necessary, accept a headache for a few days.

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