Caffeine works directly on the central nervous system, which is one reason why you can feel the results of caffeine very shortly after having a drink of coffee. Caffeine attaches itself to receptors in the human brain that process and respond to adenosine, a chemical that signals you are tired.
Adenosine is the result of a number of natural bodily processes, so the concentration of adenosine in the body is a clue to the brain when it might be time to rest or recharge. When caffeine is ingested, the caffeine molecules occupy receptors that monitor adenosine volume.
Adenosine and caffeine “compete” for these receptor spaces, so when caffeine fills them, the adenosine is not able to complete the cycle that leads to natural feelings of tiredness. This results in the powerful, but temporary feeling of wakefulness that caffeine provides, even late at night.
Over time, adenosine will attach to more and more receptors, “beating out” the caffeine that one might consume. Thus, it’s impossible to stave off tiredness with caffeine for too long.
Other Biological And Health Effects Of Caffeine
As a stimulant, caffeine promotes an elevated heart rate and greater blood circulation. While you are using caffeine, your blood pressure will likely spike for some time, although healthcare professionals are divided as to caffeine’s role in long-term hypertension concerns.
Caffeine has been used as part of a wide range of medicines and treatments. However, it is very important not to mix caffeine with other stimulants or with depressants. Caffeine can have a multiplier effect with some chemicals, or fully cancel others out.
For most people, however, caffeine intake in moderation can be part of a healthy lifestyle. In some cases, caffeine may be part of a treatment because it safely amplifies the effects of other active ingredients.