Caffeine is a substance which belongs to the family of methylxanthines. Caffeine is a psychostimulant whose main effect of increasing the heart rate after a few minutes and then cause a sensation of awakening. This feeling is manifested by a blockage of adenosine receptors, neurotransmitter inhibitor. The caffeine is largely consumed in the world as coffee and cola drinks.
The effects of caffeine on short-term health:
(With a low dose of caffeine)
- Caffeine causes vasodilation.
- Effects in the cardiovascular, respiratory and gastrointestinal tract.
- Action at the level of skeletal muscle, renal blood flow, in glycogenolysis and lipolysis.
- Contraction of blood vessels, where its properties of anti-migraine.
- Stimulates intellectual work, promotes wakefulness.
- A higher metabolic rate.
- An increase in tension.
- Increased frequency of urination.
- A rise in body temperature.
- A reduction in the duration of sleep.
- Stimulation of gastric acid secretion.
- Reduces appetite, aids digestion.
- Stimulation of secretion of bile from the gallbladder.
- Stimulation of secretion of pancreatic juice.
- Stimulation of the secretion of stomach acid gastric juice.
- Onset of diarrhea.
The effects of caffeine long term health:
(Mainly with a strong dose of caffeine, however, individual tolerances vary greatly, and these effects may occur in some people with moderate doses)
Taking too much caffeine can lead to poisoning, the symptoms:
- A phenomenon of cutaneous flushing (red face).
- An increase in diuresis.
- Involuntary muscle contractions.
- Thoughts and sentences.
- Cardiac arrhythmia.
- Psycho-motor agitation.
- An increase in heart rate.
- A transient hypertension
- Shaking hands
- Poor coordination of movements.
Regular consumption of more than 600 mg per day (about eight cups of coffee) can cause:
- Chronic insomnia
- A persistent depression
- A disturbance in the stomach often.
Effects on sleep:
The ingestion of caffeine between 30 and 60 minutes before going to bed lengthens the time to sleep, shortens total sleep time and gives a bad impression on the quality of sleep.
Caffeine is also responsible for an increased duration of stage 2 sleep and a decrease in those of stages 3 and 4.
The intensity and duration of these effects on sleep varies across individuals, depending on their ability to more or less rapid removal of caffeine.
The recommended doses of caffeine:
For children 12 and under, it is recommended a maximum daily caffeine intake of 2.5 milligrams per kilogram. If a child weighs 30 kg, the intake of caffeine quotient should not exceed 75 mg.
For women, the maximum recommended intake is 300 mg of caffeine per day, slightly more than two cups of coffee (237 ml).
For healthy men, the recommended daily maximum is 400 mg.
But be careful, regular consumption of 350 mg of caffeine (four cups of coffee) per day involves some form of physical dependence. Withdrawal symptoms include other serious headaches, irritability and fatigue. Still, over 500 mg of caffeine per day, people must be encouraged to reduce or stop their consumption.
It is often said that coffee taken at bedtime prevents falling asleep while driving but it is false, the effect of caffeine on sleep is a delayed effect.
While the effect of cardiac acceleration is almost immediate, caffeine has a peak of activity on the balance sleep / standby after five hours. A coffee in the late afternoon would be better able to stop falling asleep.
The large coffee does not have less caffeine than coffee short, caffeine is soluble in water. The more you water, the greater the amount of liquid which can dissolve the caffeine, more caffeine is extracted. In espresso brewing, where time is short and the amount of low water, there is little caffeine but much of aromas in coffee diluted.
During pregnancy, a high intake of caffeine should be avoided. Recent research has shown some possible links between high caffeine consumption and birth defects.
Caffeine is classified as moderately toxic substances, some people classify caffeine in the drug class.