Did you know that caffeine is the most accepted and least harmful stimulant drug? Yes, and it is found in higher concentrations in black tea than in coffee, although it is also found in chocolate and cola drinks.
According to experts, caffeine belongs to the group of substances called xanthine’s , whose action stimulates the brain by interfering with the action of adenosine – a nerve transmitter that produces calm and tranquility – and causes a feeling of euphoria and strength for a few hours. By increasing the levels of adrenaline and noradrenaline in the blood, it stimulates brain activity and therefore facilitates intellectual alertness and creativity.
The diuretic and stimulating effect of caffeine
Once caffeine is ingested, in one form or another, it takes between 30 and 45 minutes to reach the highest concentration levels in the blood. After three hours, half of what was absorbed has already been eliminated.
Caffeine increases heart rate and the force of heart contraction, transiently increases blood pressure. The vasoconstriction that it causes in the cerebral blood flow relieves the headache, but the stimulus that causes the increase in the secretion of gastric juices such as hydrochloric acid and pepsin, lead to irritation of the digestive mucosa.
Caffeine also has a slight diuretic effect ; increases muscle work capacity, strengthens contraction, delays and relieves fatigue . Finally, it produces a very small effect on the lungs, dilating the bronchi. Its consumption should not exceed four cups daily.