Caffeine metabolism processes

Metabolic processes speed up appreciably under the influence of caffeine. Fatty acids are released into the blood, and a general increase in metabolism is evident as there is increased muscle activity, raised temperature, or both. More calcium is made available through caffeine s action in the muscles for contraction, but this effect is evident only at caffeine doses higher than people commonly use. Gut motility and secretion increase with a release of stomach acid and digestive enzymes. Urination is also stimulated caffeine directly affects the kidneys, cutting into their ability to reabsorb electrolytes and water. For every cup of coffee or two to three cans of caffeinated soft drink consumed, about 5 mg of calcium is lost in the urine. 

Walton et al. (2001a) examined data for compounds eliminated by the cytochrome P450 isoenzymes CYP1A2 in humans. Absorption, bioavailabihty, and route of excretion were generally similar between humans and the test species for each of the substances (caffeine, paraxanthine, theobromine, and theophylline). However, interspecies differences in the route of metabolism, and the enzymes involved in this process, were identified. The magnitude of difference in the internal dose, between species, showed that values for the mouse (10.6) and rat (5.4) exceeded the fourfold default factor for toxicokinetics, whereas the rabbit (2.6) and the dog (1.6) were below this value. 

Theophylline is an example of a drug that is readily metabolized in neonates by N-methylation to caffeine (process not relevant clinically in older infants, children, and adults). It is also a compound that has pharmacologic activity versus apnea (like theophylline), but which may have toxicity when it is not readily metabolized by the liver, and its elimination is slowed by immature kidneys. ... 

The metabolism of caffeine resolves around two major phenomena, namely (a) glycogenolysis and (b) lipolysis. Fortunately, the outcome of these two biochemical processes, leading to enhanced blood-glucose and plasma lipids do not cause any alarming consequences in relatively healthy human subejcts. 

Caffeine, being an alkaloid, has various effects on human metabolism. While some of these (such as the smooth stimulating effect) are beneficial, others are not so desirable and excessive consumption of caffeine can affect health and even cause serious illness in the worst cases [6]. Some individuals suffer ill-effects even from a small amount of caffeine. In order to cater for such individuals and also for the increasing number of persons solicitous of a healthy lifestyle in general, decaffeination processes have been developed and have been in use since the beginning of this century. These processes reduce the caffeine content or, in some cases, virtually eliminate caffeine from the beans altogether. Some of the decaffeination processes involve conventional solvent extraction (section 5.3) while others involve extraction with compressed CO2 (section 5.4). 

Chronic alcoholism may also precipitate beriberi since alcohol cannot be converted to fat in the body, but must be metabolized by the same thiamin- dependent processes as carbohydrate and protein. Furthermore, alcohol increases urinary excretion of water (diuretic effect) and water-soluble vitamins. A similar, but lesser, effect may result from the heavy consumption of caffeine (in beverages such as coffee, colas, and tea) coupled with a diet chronically high in refined foods which are rich in carbohydrates. (Like alcohol, caffeine is a diuretic. Also, it stimulates the utilization of stored carbohydrate for energy.)... 

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