Caffeine, the common name for 1,3,7-trimethylxanthine ,was derived from the German word "kaffee" and the French word "café", each meaning coffee.
Caffeine is believed to be the most commonly consumed psychoactive stimulant in the globe and it has been used for thousands of years as the most widely consumed active food ingredient throughout the world. Caffeine is commonly found in beverages including coffee beans, tea leaves, cocoa beans, cola nuts and soft drinks as well as products containing cocoa or chocolate.
Here is how caffeine is metabolised in the body. Once caffeine is ingested, it's rapidly absorbed from the gastrointestinal tract into the bloodstream and become metabolised (broken down) in the liver and finally it's filtered by the kidney and exist the body with the urine.
You may ask, how long does it take caffeine to leave the body? It varies between individuals for instance, an average adult -3 to 5 hours, child less than 6 months -24 hours, pregnant women -7 to 8 hours, and smokers- 2 to 3 hours.
Does caffeine has physiological effects? Yes it does which the reason most people drink coffee in the morning and in between work periods, caffeine has been shown to stimulate the central nervous system, to stimulate cardiac muscle, and to relax smooth muscle, especially bronchial muscle, and to act on the kidney to produce diuresis. Caffeine also produces a slight increase in the nasal metabolic rate and increases the capacity for muscular work. It is also well established that caffeine delays the onset of sleep and produces a disturbed sleep pattern during the first 3-4hours. Caffeine has been associated with hyperactivity in children, but this normally results from consumption of caffeine containing soft drinks.
Caffeine have restorative effect on functions such as physical endurance, writing and monitoring of equipment when these are diminished by fatigue. It has also the ability to improve sporting performance when determined by parameters such as the power of a boxers punch or the aerobic and anaerobic capacity of an athlete.
Let's state plainly the potential positive and negative effect of caffeine.
Positive effect:
- Increased attention and alertness, and decreased fatigue.
- Lower risk of cardiovascular disease.
- Lower risk of diabetes.
- Increased metabolic rate
Negative effect:
- Anxiety and addiction.
- Increased vasoconstriction and blood pressure.
- Reduced control of fine motor movements.
- Increased stimulation of urination.
If caffeine is not taking in moderation it can cause depletion of important nutrients, like vitamin B6 and interfere with nutrient absorption of essential minerals, including calcium, iron, magnesium and B vitamins.
However, consumption of caffeine should not exceed three cups of coffee per day, or not more than 300mg/day to avoid adverse effects.