Caffeine is the most important and famous component of coffee. It is the main reason why you stay awake and lively after drinking a cup of this dark liquid. This substance stimulates the nervous system; therefore you have the feeling of improving your mental lucidity. Furthermore, if you are a student you should know how it works, it helps memory, improves your speaking skills, relieves fatigue and stimulates the muscle tone. The nutritional properties of caffeine are, actually, very important and sought after if you are ready to spend a night without sleeping and you must be lucid and concentrated. However, an excessive consumption of coffee might cause insomnia and increase the pulse. It is important to remember that every person has different reactions to the nutritional properties of caffeine: some people drink coffee after dinner and some don’t, because it causes insomnia. Some people are helped during the digestion, whereas others have stomach ache.
Caffeine is more concentrated in a long coffee, like the American coffee or the one prepared with the Neapolitan coffee pot, than in a cup of espresso. From the surveys made in this sector, one cup of espresso contains no more than 80 mg of caffeine, whereas in a cup of long coffee 150 mg.
Since the effects are very different depending on the people, the caffeine content in a product must be listed on the label if it is more than 150 mg/l. This is stated in the European directive 2002/67/CE, which applies to some non alcoholic and energy drinks, but not to tea, coffee and the products made with them. Since it is clear to the consumer that such products contain caffeine, the quantity might not be declared, because it depends on the infusion time.
One interesting fact: it has been proved that caffeine does not cause addiction. If the usual consumption is interrupted, only in rare cases you will get headache, tiredness or sleepiness. Usually these symptoms last only one or two days and might be avoided if the caffeine consumption is gradually reduced.