Caffeine's wakefulness mechanism. Daniel Machine.
First: Caffeine has a similar structure to Adenosine. They take place of Adenosine in the receptors and stimulate the nervous system (making Adenosine unable to meet the receptors). The nervous system is more active and one of the consequences is that we are more alert, more agile. So the drivers driving the roads, the people who work hard ... all drink coffee to become lucid
Second: Caffeine also causes the body to increase its production of adrenaline - a hormone produced by the body when you are scared, angry or excited, which makes your heart beat faster and your body prepare for Reaction against danger.
In addition, Caffeine also prevents Phosphodiesterase from decomposing the secondary CAMP, so the euphoric signal generated by Adrenaline is amplified and then maintained longer than usual. This increases the efficiency of muscle cells in response to adrenaline, which means maintaining the brain's excitement, making us feel alert in the morning or insomnia in the evening. Therefore, Caffeine makes the body in a state of alertness.
Because of its awakening role to the brain and the prolongation of muscle efficiency, Caffeine has always been considered the "substrate of civilized society" - The driving force that always drives people to revolution, civil society owner, industrialized and truly happy.
Duration of action & decomposition of Caffeine
Caffeine from coffee or other beverages is absorbed by the small intestine within 45 minutes after eating and distributed in all body tissues. Stable blood levels are reached within 1-2 hours
The half-life of caffeine (the time it takes for the body to eliminate half of the dosage) is very different for each person and depends on many factors such as pregnancy, other drugs, and the function of the enzymes in the liver and age .. In healthy adults, the half-life of Caffeine is from 3 to 7 hours (According to Wikipedia).
Safe dosage of Caffeine
The amount of caffeine that each person can consume is completely different because depending on each person's ability to break down caffeine, some are almost "immune" to the effects of this stimulant, while others are close to such as "extreme stress and hyperactivity" even with a small cup of coffee. You can refer to the calculation of Caffeine consumption to know exactly how many cups of coffee can "drink" into the body every day. Particularly for those who are sensitive to caffeine but still love the taste of coffee, Decaf coffee is an alternative.
Common caffeine doses are as follows:
Healthy adults and no pathological factors: 300-400 mg Caffeine a day - Equivalent to 5 Espresso Cups (25-30ml)
Also for normal people as above, the death dose is about 75-100 cups of coffee - equivalent to 150 -200mg of Caffeine / 1kg of body weight.