Caffeine is a central nervous system stimulant (CNS) of the methylxanthine class. It is the most consumed psychoactive drug in the world. Unlike many other psychoactive substances, it is legal and unregulated in almost all parts of the world. There are several known mechanisms of action to explain the effects of caffeine. Most notably, it is reversibly blocking the action of adenosine on its receptor and consequently preventing the drowsiness caused by adenosine. Caffeine also stimulates certain parts of the autonomic nervous system.
Caffeine is a bitter white crystalline purine, alkaloid methylxanthine, and is chemically related to adenine and guanine from deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). These are found in seeds, nuts, or leaves from a number of native plants of South America and East Asia and help protect them against predatory insects and prevent the germination of nearby seeds. The most famous source of caffeine is coffee beans, mistaken for plant seeds Coffea . Beverages containing caffeine are digested to relieve or prevent drowsiness and improve performance. To make this drink, caffeine is extracted with soaking plant products in water, a process called infusion. Drinks containing caffeine, such as coffee, tea, and cola, are popular; In 2014, 85% of American adults consume some form of caffeine every day, consuming 164 mg on average.
Caffeine can have positive and negative health effects. Can treat and prevent premature infant respiratory dysplasia bronchopulmonary prematurity and prematurity apnea. Caffeine citrate is in the WHO Essential Medicines List. This may have a modest protective effect against some diseases, including Parkinson's disease. Some people experience sleep disturbances or anxiety if they consume caffeine, but others show little disturbance. Proof of risk during pregnancy is still vague; some experts suggest that pregnant women limit consumption to the equivalent of two cups of coffee per day or less. Caffeine can produce a form of mild drug dependence - associated with withdrawal symptoms such as drowsiness, headaches, and irritability - when an individual stops using caffeine after repeating the daily intake. Tolerance to the autonomic effects of increased blood pressure and heart rate, and increased urine output, develops with chronic use (ie, these symptoms become less obvious or do not occur after consistent use).
Caffeine is classified by the US Food and Drug Administration as "generally recognized as safe" (GRAS). Toxic doses, more than 10 grams per day for adults, are much higher than the usual doses below 500 milligrams per day. A cup of coffee contains 80-175 mg of caffeine, depending on what "bean" (seed) is used and how it is prepared (eg, dripping, percolation, or espresso). Thus it takes about 50-100 cups of ordinary coffee to reach a lethal dose. However, pure caffeine powder, which is available as a dietary supplement, can be deadly in the amount of a tablespoonful.
Video Caffeine
Use
Medical
Caffeine is used in:
- Bronchopulmonary dysplasia in premature infants for prevention and treatment. It can increase weight during therapy and reduce the incidence of cerebral palsy and reduce language and cognitive delays. On the other hand, long-term side effects are subtle is possible.
- Apnea prematurity as the main treatment, but not prevention.
- Treatment of orthostatic hypotension.
Improved performance
Cognitive
Caffeine is a central nervous system stimulant that reduces fatigue and drowsiness. At normal doses, caffeine has a variable effect on learning and memory, but generally increases reaction time, awake, concentration, and motor coordination. The amount of caffeine needed to produce this effect varies from person to person, depending on body size and tolerance level. The desired effect occurs about an hour after consumption, and the desired effect of moderate doses usually subsides after about three or four hours.
Caffeine may delay or prevent sleep and improve task performance during sleep deprivation. The shift of workers using caffeine makes fewer errors due to drowsiness.
A systematic review and meta-analysis from 2014 found that concurrent caffeine use and L -nineine have synergistic psychoactive effects that promote alert alertness, attention and shift; this effect is most prominent during the first hour of post-dosing.
Physical
Caffeine is a proven ergogenic aid in humans. Caffeine improves athletic performance in aerobics (especially endurance sports) and anaerobic conditions. Moderate doses of caffeine (about 5 mg/kg) can improve running performance, cycling and performing test performance, endurance (ie, initial delay of muscle fatigue and central fatigue), and cycling power output. Caffeine increases the basal metabolic rate in adults.
Caffeine increases muscle strength and strength, and can increase muscle endurance. Caffeine also improves performance in anaerobic tests. Consumption of caffeine prior to constant load training is associated with reduced exertion. Although this effect does not exist during fatigue exercises, performance increases significantly. This is congruent with caffeine reducing the exertion perceived, since exercise for fatigue must end at the same point of exhaustion.
Specific population
Adult
For the general population of healthy adults, Canadian Health recommends a daily intake of no more than 400 mg.
Children
In healthy children, caffeine intake produces a "simple and usually harmless" effect. There is no evidence that coffee inhibits a child's growth. For children aged 12 and under, Health Canada recommends a maximum daily caffeine intake of no more than 2.5 milligrams per kilogram of body weight. Based on the average weight of children, this translates to the limit of intake based on the following ages:
Teen
Health Canada has not developed advice for teenagers because of insufficient data. However, they suggest that daily intake of caffeine for this age group is no more than 2.5 mg, mg/kg body weight. This is because the maximum dose of adult caffeine may be inappropriate for mild teenagers or for younger teenagers who are still growing. A daily dose of 2.5 mg/kg body weight will not cause adverse health effects on the majority of teen caffeine consumers. This is a conservative suggestion because older and heavier adolescents may be able to consume adult dose caffeine without suffering any side effects.
Pregnancy and breast-feeding
The UK Food Standards Agency has recommended that pregnant women should limit their caffeine intake, from caution, to less than 200 mg of caffeine per day - equivalent to two cups of instant coffee, or one half to two cups of fresh coffee. The American Congress of Obstetricians and Gynecologists (ACOG) concluded in 2010 that caffeine consumption is safe for up to 200 mg per day in pregnant women. For women who are breastfeeding, being pregnant, or possibly pregnant, Health Canada recommends a daily maximum daily caffeine intake of no more than 300 mg, or slightly more than two 8 oz (237 ml) coffee cups.
There are conflicting reports in the scientific literature on caffeine use during pregnancy. A 2011 review found that caffeine during pregnancy does not seem to increase the risk of congenital malformation, miscarriage or growth retardation even when taken in moderate to high amounts. However, other reviews conclude that there is some evidence that higher caffeine intake by pregnant women may be associated with a higher risk of low birth weight babies, and may be associated with a higher risk of miscarriage. A systematic review, analyzing the results of observational studies, shows that women who consume large amounts of caffeine (more than 300 mg/day) before pregnancy may have a higher risk of miscarriage.
Maps Caffeine
Adverse effects
Physical
Caffeine can increase blood pressure and cause vasoconstriction. Coffee and caffeine can affect gastrointestinal motility and gastric acid secretion. Caffeine in low doses can cause a weak bronchodilation of up to four hours in people with asthma. In postmenopausal women, high caffeine consumption can accelerate bone loss.
The dose of caffeine is equivalent to the amount normally found in the standard portion of tea, coffee, and soft drinks so does not appear to have diuretic action. However, acute consumption of caffeine in large doses (at least 250-300 mg, equivalent to the amount found in 2-3 cups of coffee or 5-8 cups of tea) results in short-term urine output stimulation in individuals who have been deprived of caffeine for several days or weeks. This increase is due to both diuresis (increased water excretion) and natriuresis (increased saline excretion); it is mediated through the proximal tubular adenosine receptor blockade. An acute increase in urine output may increase the risk of dehydration. However, chronic caffeine users develop tolerance to this effect and do not experience an increase in urine output.
Psychological
Unwanted minor symptoms of caffeine consumption are not severe enough to ensure a psychiatric diagnosis is common and includes mild anxiety, anxiety, insomnia, increased sleep latency, and reduced coordination. Caffeine can have a negative effect on anxiety disorders. According to a 2011 literature review, caffeine use positively correlates with anxiety and panic disorder. At high doses, usually greater than 300 mg, caffeine can cause and worsen anxiety. For some people, discontinuing caffeine use can significantly reduce anxiety. In moderate doses, caffeine has been associated with reduced depressive symptoms and lowered risk of suicide.
Some textbooks state that caffeine is a mild euphoriant, others claim that it is not euphoriant, and one states that it is and is not an euphoriant.
Improvement disorder
Dependency
Whether caffeine can cause an addictive disorder depends on how the addiction is defined. Consumption of compulsive caffeine under any circumstances has not been observed, and caffeine is therefore generally not considered addictive. However, some diagnostic models, such as ICDM-9 and ICD-10, include the caffeine addiction classification under the broader diagnostic model. Some claim that certain users can become addicted and therefore can not reduce their use even if they know there are negative health effects.
Caffeine does not seem to be a reinforcing stimulus, and some degree of aversion may actually occur, with people preferring placebo rather than caffeine in the study of the drug abuse obligations published in the NIDA research monograph. Some stated that the study did not provide support for the underlying biochemical mechanisms for caffeine addiction. Other research suggests it may affect the reward system.
"Caffeine addiction" was added to ICDM-9 and ICD-10. However, the addition is contradicted by claims that the caffeine addiction diagnostic model is not supported by evidence. The American Psychiatric Association's DSM-5 does not include the caffeine addiction diagnosis but proposes the criteria for the disorder for further study.
Dependency and withdrawal
Withdrawal may cause clinically significant mild or minor damage or damage in daily functioning. The frequency at which this occurred was reported alone at 11%, but in laboratory tests only half of the people who reported the withdrawal actually experienced it, raises doubts on many dependency claims. Mild physical dependence and withdrawal symptoms may occur when not taking abstinence, with more than 100 mg of caffeine per day, although these symptoms persist for no more than a day. some symptoms associated with psychological dependence may also occur during withdrawal. Caffeine dependence may involve withdrawal symptoms such as fatigue, headache, irritability, depressed mood, reduced satisfaction, inability to concentrate, drowsiness or drowsiness, stomach pain, and joint pain.
ICD-10 includes a diagnostic model for caffeine dependence, but DSM-5 does not. APA, which publishes DSM-5, recognizes that there is sufficient evidence to create a caffeine-dependent diagnostic model for DSM-5, but they note that the clinical significance of this disorder is unclear. The DSM-5 instead lists the "disruption of caffeine usage" in the model section that comes from the manual.
Tolerance to caffeine effects occurs due to increased blood pressure in caffeine and subjective feelings of nervousness. Sensitization, the process by which effect becomes more prominent with use, occurs for positive effects such as feelings of alertness and well-being. Tolerance varies for regular daily caffeine users and high caffeine users. High doses of caffeine (750 to 1200 mg/day spread throughout the day) have been shown to produce full tolerance for some, but not all caffeine effects. Doses as low as 100 mg/day, such as 6 ounces coffee cups or two to three servings of 12 ounces of caffeinated soft drinks, may continue to cause sleep disturbance, among other intolerances. Users of non-regular caffeine have caffeine tolerance at least for sleep disorders. Some coffee drinkers develop tolerance to the effects of disturbing unwanted sleep, but others do not seem to.
Other disease risks
The protective effects of caffeine on Alzheimer's disease and dementia may occur but evidence can not be inferred. It can protect people from cirrhosis of the liver. Caffeine can reduce the severity of acute mountain diseases if taken several hours before reaching high altitudes. One meta-analysis found that caffeine consumption was associated with a reduced risk of type 2 diabetes. Two meta-analyzes have reported that caffeine consumption is associated with a linear reduction in the risk of Parkinson's disease. Caffeine consumption may be associated with a reduced risk of depression, although conflicting results have been reported.
Caffeine increases intraocular pressure in those with glaucoma but does not appear to affect normal individuals.
Overdose
Consumption of 1-1.5 grams (0.035-0.053 oz) per day is associated with a condition known as caffeinism . Caffeine usually combines caffeine dependence with a variety of unpleasant symptoms. including nervousness, irritability, anxiety, insomnia, headaches, and palpitations after caffeine use.
Caffeine overdose can lead to a state of over-stimulation of the central nervous system called caffeine poisoning (DSM-IV 305.90). This syndrome usually occurs only after the consumption of caffeine in large quantities, exceeds the amount found in caffeinated beverages and caffeine tablets (eg, more than 400-500 mg each time). Symptoms of caffeine poisoning are comparable to other symptoms of over-stimulation of stimulants: they may include anxiety, anxiety, anxiety, excitement, insomnia, facial flushing, increased urination, gastrointestinal disorders, twitch muscles, thought flow and rambling speech, irritability, irregular or rapid heart, and psychomotor agitation. In the case of a much larger overdose, mania, depression, deviations in judgment, disorientation, disinhibition, delusions, hallucinations, or psychosis may occur, and rhabdomyolysis (skeletal muscle tissue damage) can be provoked.
Massive overdose can cause death. LD 50 Caffeine in humans depends on individual sensitivity, but it is estimated at 150-200 milligrams per kilogram of body mass (75-100 cups of coffee for 70 kilograms adults). A number of deaths have been caused by an overdose of powdered caffeine supplement available, which is estimated to be less than one tablespoon of deadly. The lethal dose is lower in individuals whose ability to metabolize caffeine is impaired due to genetics or chronic liver disease. Death is reported in a man with overdose liver cirrhosis in caffeinated mint candy.
Treatment of mild caffeine intoxication is directed to relieve symptoms; Severe poisoning may require peritoneal dialysis, hemodialysis, or haemofiltration.
Interactions
Alcohol
According to DSST, alcohol provides performance reduction and caffeine has a significant performance increase. When alcohol and caffeine are consumed together, the effects of caffeine are affected, but the effects of alcohol remain the same. For example, when additional caffeine is added, the effects of drugs produced by alcohol are not reduced. However, the anxiety and alertness given by caffeine decreases when additional alcohol is consumed. Alcohol consumption alone reduces aspects of inhibition and activation of behavioral controls. Caffeine antagonizes the activation aspect of behavior control, but has no effect on control of inhibitory behavior.
Tobacco
Tobacco smoking increases caffeine clearance by 56%.
Birth control
Birth control pills may lengthen the caffeine half, requiring greater attention to caffeine consumption.
Drugs
Caffeine sometimes increases the effectiveness of some medications, such as a cure for headaches.
Pharmacology
Pharmacodynamics
In the absence of caffeine and when someone is awake and alert, a little adenosine is present in the neuron (CNS). With a continuous state of mind, over time accumulates in the synapse of the nerve, in turn binds and activates the adenosine receptor found in certain CNS neurons; when activated, these receptors produce cellular responses that ultimately increase drowsiness. When caffeine is consumed, it antagonizes the adenosine receptor; in other words, caffeine prevents adenosine from activating the receptor by blocking the location at the receptor where adenosine binds to it. As a result, caffeine temporarily prevents or alleviates drowsiness, and thus maintains or restores vigilance.
Target prescription and ion channels
Caffeine is the antagonist of the four subtypes of the adenosine receptor (A 1 , A 2A , A 2B , and A 3 ) , albeit with various potentials. The affinity value (K D ) caffeine for human adenosine receptor is 12Ã,? M on A 1 , 2,4Ã,? M on A 2A , 13Ã,? M at A 2B , and 80Ã,? M in A 3 . The mouse knockout research specifically involves the receptor antagonism of A 2A as being responsible for the caffeine promoting effects that increase awareness. The antagonism of the adenosine receptor by caffeine stimulates the vagal, vasomotor, and medullary respiratory centers, which increases respiratory rates, reduces heart rate, and constricts blood vessels. Adenosine receptor antagonism also promotes the release of neurotransmitters (eg, Monoamines and acetylcholine), which provide caffeine with its stimulant effects; adenosine acts as a neurotransmitter inhibitor that suppresses activity in the central nervous system. Heart palpitations are caused by a receptor blockade A 1 .
Because caffeine is soluble in water and fat, it easily crosses the blood-brain barrier that separates blood flow from the inside of the brain. Once in the brain, the main mode of action is as a non-selective antagonist of the adenosine receptor (in other words, an agent that reduces the effects of adenosine). Caffeine molecules are structurally similar to adenosine, and are able to bind adenosine receptors on the cell surface without activating them, thus acting as competitive antagonists.
In addition to its activity on adenosine receptors, caffeine is a trisphosphate 1 inositol receptor antagonist and an independent activator of ryanodine receptors (RYR1, RYR2, and RYR3). It is also a competitive antagonist of ionotropic glycine receptors.
Effects on striatal dopamine
While caffeine does not directly bind to dopamine receptors, it affects the activity of binding of dopamine to its receptor in striatum by binding to adenosine receptors that have formed GPCR heteromers with dopamine receptors, in particular A 1 - D 1 receptor heterodimer (this is a receptor complex with 1 adenosine receptor A 1 and 1 dopamine receptor D 1 ) and A 2A -D 2 receptor heterotetramer (this is a receptor complex with 2 adenosine receptors A 2A and 2 dopamine D 2 receptors). A 2A -D 2 heterotetramer receptors have been identified as major caffeine pharmacological targets, primarily due to mediate some psychostimulan effects and pharmacodynamic interactions with dopaminergic psychostimulants.
Caffeine also causes dopamine release in the dorsal striatum and nucleus accumbens nucleus, but not the nucleus accumbens shell, hostile to the A 1 receptor at the dopamine neuron axle terminal. and A 1 -A 2A heterodimer (receptor complex consisting of 1 adenosine A 1 receptor and 1 adenosine A 2A receptor) in the axon terminal of glutamate neuron. During chronic caffeine use, the release of caffeine-induced dopamine in nucleus accumbens is markedly reduced due to drug tolerance. Enzyme Target
Caffeine, like other xanthines, also acts as a phosphodiesterase inhibitor. As a competitive nonselective phosphodiesterase inhibitor, caffeine increases intracellular cAMP, activates protein kinase A, inhibits TNF-alpha synthesis and leukotriene, and reduces innate inflammation and immunity. Caffeine also affects the cholinergic system in which it inhibits the enzyme acetylcholinesterase.
Non-target effects
Caffeine antagonizes the A2A adenosine receptor in the ventrolateral preoptic area (VLPO), thereby reducing GABA neurotransmission inhibition to the tuberomammillary nucleus, the activation-dependent histaminergic projection nucleus promoting arousal. Disinhibition of the tuberomammary core is the main mechanism by which caffeine produces a promotional effect that raises awareness.
Pharmacokinetics
Caffeine from coffee or other beverages is absorbed by the small intestine within 45 minutes after being absorbed and distributed throughout the body tissues. Peak blood concentration is achieved in 1-2 hours. It was eliminated by first-order kinetics. Caffeine can also be absorbed rectally, as evidenced by the suppository ergotamine tartrate and caffeine (to relieve migraines) and chlorobutanol and caffeine (for the treatment of hyperemesis). However, rectal absorption is less efficient than oral: the maximum concentration (C max ) and the total amount absorbed (AUC) are both about 30% (ie, 1/3) of the oral amount.
Biological half-time caffeine - the time it takes the body to eliminate half the dose - varies widely among individuals according to factors such as pregnancy, other drugs, liver enzyme function levels (required for caffeine metabolism) and age. In healthy adults, the half-life of caffeine is between 3-7 hours. Smoking reduces half-life to 30-50%, while oral contraceptives can double it and pregnancy can increase it by up to 15 hours during the last trimester. In newborns, half-life can be 80 hours or more, declining very quickly with age, may be less than the adult value at 6 months of age. The fluvoxamine antidepressant (Luvox) reduces caffeine clearance by more than 90%, and increases the elimination of the beak by more than tenfold; from 4.9 hours to 56 hours.
Caffeine is metabolized in the liver by the P450 cytochrome oxide enzyme system, in particular, by CYP1A2 isozyme, into three dimethylxanthines, each having its own effects on the body:
- Paraxanthine (84%): Increases lipolysis, causes increased glycerol and free fatty acid levels in blood plasma.
- Theobromine (12%): Dilates the blood vessels and increases the volume of urine. Theobromine is also a major alkaloid in cocoa (brown).
- Theophylline (4%): Stretches the smooth muscles of the bronchus, and is used to treat asthma. Theophylline therapeutic dose, however, is many times greater than the level achieved from caffeine metabolism.
1,3,7-Trimethyluric acid is a minor caffeine metabolite. Each of these metabolites is further metabolized and then excreted in the urine. Caffeine can accumulate in individuals with severe liver disease, increasing half-life.
A 2011 review found that increased caffeine intake was associated with variation in the two genes that increased the rate of caffeine catabolism. The subjects who experienced this mutation on both chromosomes consumed 40 mg more caffeine per day than others. This may be due to the need for higher intake to achieve a comparable desirable effect, not that the gene causes disposition for greater habituation incentives.
Chemistry
Pure anhydrous caffeine is a powder with no bitter white odor with a melting point of 235-238 Â ° C. Caffeine is sufficiently soluble in water at room temperature (2 g/100 mL), but is very soluble in boiling water (66 g/100 mL). It is also quite soluble in ethanol (1.5 g/100 mL). This is a weak base (pK a of the conjugate base = ~ 0.6) which requires a strong acid to protect it. Caffeine does not contain a stereogenic center and is therefore classified as an akiral molecule.
The xanthine core of caffeine contains two fused rings, a pyrimidinedione and imidazole. The pyrimidine in turn contains two amide functional groups which are predominantly in the zwitterion resonance, the place from which the nitrogen atom is attached to the adjacent amide carbonide atom. Therefore all six atoms in the pyrididine ring system are sp 2 hybridization and planar. Therefore, the integral 5.6 ring core of caffeine contains a total of ten electrons pi and hence according to the rules of HÃÆ'¼ckel is aromatic.
Synthesis
Caffeine biosynthesis is an example of convergent evolution among different species.
Caffeine can be synthesized in the laboratory starting with dimethylurea and malonic acid.
Commercial caffeine is not usually produced synthetically because these chemicals are already available as a by-product of decaffeination.
Decaffeination
Extraction of caffeine from coffee, to produce caffeine and decaffeinated coffee, can be done using a number of solvents. Benzene, chloroform, trichlorethylene and dichloromethane have all been used for years but for reasons of safety, environmental impact, cost, and taste, they have been replaced by the following main methods:
- Water extraction: Coffee beans are soaked in water. Water, which contains many other compounds other than caffeine and contributes to the taste of coffee, is then passed through activated charcoal, which removes caffeine. The water can then be reintroduced with the beans and dries dry, leaving the decaf coffee with the original flavor. Coffee producers recover caffeine and resell it for use in soft drinks and over-the-counter caffeine tablets.
- Supercritical Carbon Dioxide Extraction: Supercritical carbon dioxide is an excellent nonpolar solvent for caffeine, and safer than the organic solvents used. A simple extraction process: CO 2 is forced through green coffee beans at temperatures above 31.1 ° C and pressures above 73 atm. In this condition, CO 2 is in a state of "supercritical": It has a gas-like property that allows it to penetrate deep into the seed but also the liquid-like properties that dissolve 97-99% caffeine. CO containing caffeine 2 then sprayed with high pressure water to remove caffeine. Caffeine can then be isolated by charcoal adsorption (as above) or by distillation, recrystallization, or reverse osmosis.
- Extraction by organic solvents: Certain organic solvents such as ethyl acetate present far less health and environmental hazards than previously chlorinated and aromatic organic solvents. Another method is to use triglyceride oil obtained from the spent coffee powder.
"Decaffeinated" coffee actually contains caffeine in many cases - some commercially available decaffeinated coffee products contain high levels. One study found that decaffeinated coffee contains 10 mg of caffeine per cup, compared with about 85 mg of caffeine per cup for regular coffee.
Detection in body fluids
Caffeine can be quantified in blood, plasma, or serum to monitor therapy in neonates, confirm the diagnosis of poisoning, or facilitate investigation of medicolegal death. Plasma caffeine levels are usually in the range of 2-10 mg/L in coffee drinkers, 12-36 mg/L in neonates receiving treatment for apnea, and 40-400 mg/L in acute overdose victims. The concentration of urinary caffeine is often measured in competitive sports programs, where rates over 15 mg/L are usually considered to represent abuse.
Analog
Several analogue substances have been created that mimic the nature of caffeine by function or structure or both. Of the last group are xanthines DMPX and 8-chlorotheophylline, which are the ingredients in dramamine. Members of the nitrogen substituted xanthines class are often proposed as potential alternatives to caffeine. Many other xanthine analogues that are of the adenosine receptor antagonist class have also been described.
Some other caffeine analogues:
- Dipropylcyclopentylxanthine
- 8-Cyclopentyl-1,3-dimethylxanthine
- 8-Phenyltheophylline
Tannin Precipitation
Caffeine, like other alcaloids such as cinchonine, quinine or strychnine, precipitates polyphenols and tannins. This property can be used in quantization methods.
Natural events
About sixty plant species are known to contain caffeine. Common sources are "beans" (seeds) of two cultivated coffee plants, Coffea arabica and Coffea canephora (quantity varies, but 1.3% is a typical value); in tea plant leaves; and in cola nuts. Other sources include holly yaupon leaves, yellow mated leaves of South American mate, seeds from Amazonle maple guarana berry, and holly guayusa leaf Amazon. A moderate climate around the world has produced plants containing unrelated caffeine.
Caffeine in the plant acts as a natural pesticide: it can paralyze and kill the predatory insects that feed on the plant. High levels of caffeine are found in coffee seedlings when they develop leaves and have no mechanical protection. In addition, high levels of caffeine are found in the surrounding soil of coffee seedlings, which inhibits the germination of the seeds of nearby coffee seeds, thus providing the seeds with the highest caffeine levels fewer competitors for the existing resources to survive. Caffeine is stored in tea leaves in two places. First, in the cell vacuoles where it is complexed with polyphenols. This caffeine may be released into the insect's mouth, to prevent herbivores. Secondly, around the vascular bundle, which may inhibit the pathogenic fungus from entering and colonizing the vascular collection. Caffeine in the nectar can increase the reproductive success of pollen-producing crops by enhancing the memory of pollinating gifts such as honey bees.
Different perceptions in the swallowing effect of beverages made from various caffeine-containing plants can be explained by the fact that they also contain various other methylxanthine alkaloid mixtures, including theophyline and theobromine cardiac stimulants, and polyphenols that can form soluble complexes with caffeine..
Products
Products containing caffeine are coffee, tea, soft drinks ("colas"), energy drinks, other beverages, chocolate, caffeine tablets, other oral products, and inhalation.
Beverage
Coffee
The main source of caffeine in the world is the "seed" of coffee (coffee plant seed), from which coffee is brewed. The content of caffeine in coffee varies greatly depending on the type of coffee bean and the preparation method used; even beans in certain shrubs can show variations in concentrations. In general, one serving of coffee ranges from 80 to 100 milligrams, for one shot (30 milliliters) of arabica espresso, up to about 100-125 milligrams for one cup (120 milliliters) of coffee drops. Arabica coffee typically contains half the caffeine of the robusta variety . In general, dark roasted coffee has slightly less caffeine than lighter roasted meats because the roasting process reduces the amount of caffeine content in nuts. Tea
Tea contains more caffeine than coffee with dry weight. However, the typical presentation, contains much less, because fewer products are used than equivalent coffee. Also contributing to caffeine content are growth conditions, processing techniques, and other variables. Thus, tea contains varying amounts of caffeine.
Tea contains a little teobromin and a little theophylline than coffee. Preparation and many other factors have a significant impact on tea, and color is a very bad caffeine indicator. Tea like pale Japanese green tea, gyokuro , for example, contains much more caffeine than darker teas like lapsang souchong , which has very little.
Soft drinks and energy drinks
Caffeine is also a common ingredient of soft drinks, such as cola, originally made from kola nuts. Soft drinks usually contain 0 to 55 milligrams of caffeine per serving of 12 ounces. In contrast, energy drinks, such as Red Bull, can start at 80 milligrams of caffeine per serving. Caffeine in this beverage derives from the ingredients used or additives derived from decaffeinated products or from chemical synthesis. Guarana, the main ingredient of energy drinks, contains large amounts of caffeine with a small amount of theobromine and theophylline in a slow release excipient that occurs naturally.
Other drinks
- Mate is a popular drink in many parts of South America. The preparation consists of filling the pumpkin with South American yellow mate leaves, pouring hot water but not boiling on the leaves, and drinking with a straw, bombilla, which acts as a filter so that only the liquid draws and not the yerba leaves.
- GuaranÃÆ'¡ seed ("bean") is used to make commercially sold drinks GuaranÃÆ'¡ Antarctica, originally from Brazil and is currently the fifth most popular soft drink in the world.
- Leaves of Ilex guayusa , Ecuadorian hollywood trees, are placed in boiling water to make guayusa tea, locally brewed and sold commercially throughout the world.
Chocolate
Chocolate derived from cocoa beans contains less caffeine. The weak stimulant effect of chocolate may be due to a combination of theobromine and theophylline, as well as caffeine. A serving of 28 grams of milk chocolate has a portion of caffeine as much as a cup of decaffeinated coffee. Severe, dark chocolate has one to two times the amount of caffeine as coffee: 80-160 mg per 100 g. Higher percentages of cocoa such as the amount of 90% to 200 mg per 100 g approximately and thus, 100-gram of 85% chocolate bars contain about 195 mg of caffeine.
Tablet
Tablets offer several advantages over coffee, tea and other caffeinated beverages, including comfort, known dosage, and avoiding intake of sugars, acids, and liquids simultaneously. Manufacturers of caffeine tablets claim that using quality pharmaceutical caffeine increases mental alertness. These tablets are typically used by students who study for their exams and by people who work or drive for hours on end.
Other spoken products
One US company is marketing a reconstituted oral caffeine strip. Another intake route is SpazzStick, caffeinated lip balm. Warning Energy Caffeine Gum was introduced in the United States in 2013, but was voluntarily withdrawn following the FDA's inquiry into the health effects of caffeine added in food.
Inhalants
There are several products that are marketed that offer inhalers that provide an exclusive supplement mix, with caffeine as the main ingredient. In 2012, the FDA sent a warning letter to one of the companies that marketed this inhaler, expressing concerns about the lack of available security information about caffeine being inhaled.
Combination with other drugs
- Some drinks combine alcohol with caffeine to make caffeinated beverages. The effects of caffeine stimulants can mask the effects of alcohol depressants, potentially reducing the awareness of the user to their poisoning level. Such drinks have been subjected to a ban due to security concerns. In particular, the US Food and Drug Administration has classified caffeine added to malt liquor as an "unsafe food additive".
- Yes ba contains a combination of methamphetamine and caffeine.
- Painkillers like propyphenazone/paracetamol/caffeine combine caffeine with analgesics.
History
Discovery and deployment of usage
According to Chinese legend, Chinese emperor Shennong, famous for ruling around 3000 BC, accidentally discovered tea when he noted that when certain leaves fall into boiling water, fragrant and refreshing beverages are produced. Shennong is also mentioned in Lu Yu Cha Jing , a famous early work on tea.
The earliest credible evidence of coffee or coffee plant knowledge emerged in the mid-fifteenth century, in Sufi monasteries in southern Yemen. From Mocha, coffee spread to Egypt and North Africa, and by the 16th century it had reached the whole of the Middle East, Persia and Turkey. From the Middle East, drinking coffee spread to Italy, then throughout Europe, and coffee plants transported by the Dutch to the Indies and to America.
The use of kola nuts seems to have ancient origins. It is chewed in many West African cultures, both in private and social settings, to restore vitality and reduce hunger.
The earliest evidence of the use of cocoa beans comes from residues found in ancient Mayan pots dated 600 BC. Also, chocolate is consumed in a bitter and spicy drink called xocolatl , often flavored with vanilla, cayenne, and achiote. Xocolatl is believed to fight fatigue, a belief that may be caused by theobromine and caffeine content. Chocolate is an important luxury item throughout Mesoamerica pre-Columbian, and chocolate seeds are often used as currency.
Xocolatl was introduced to Europe by the Spaniards, and became a popular drink in 1700. The Spaniards also introduced cocoa trees to the West Indies and the Philippines. It is used in the alchemical process, where it is known as "black bean".
Leaves and stems from holly yaupon ( Ilex vomitoria ) are used by Native Americans to make tea called asi or "black drinks". Archaeologists have found evidence of this usage far into antiquity, perhaps dating to the time of the Archaic End.
Chemical identification, isolation, and synthesis
In 1819, German chemist Friedlieb Ferdinand Runge isolated pure caffeine for the first time; he calls it "Kaffebase" (that is, the base in coffee). According to Runge, he did this on the orders of Johann Wolfgang von Goethe. In 1821, caffeine was isolated by both French chemist Pierre Jean Robiquet and by a pair of other French chemists, Pierre-Joseph Pelletier and Joseph Bienaimà ©  © Caventou, according to the Swedish chemist JÃÆ'¶ns Jacob Berzelius in his annual journal. Furthermore, Berzelius states that French chemists have made their discovery independently of knowledge of Runge or their respective occupations. However, Berzelius later acknowledged Runge's priority in extracting caffeine, stating: "However, at this point, it should not remain unspecified that Runge (in his Phytochemical Discovery, 1820, pages 146-147) determined the method and explains caffeine under the name Caffeebase a year earlier than Robiquet, to whom the discovery of this substance is usually attributed, after making the first oral announcement of it at a Pharmaceutical Society meeting in Paris. "
The Pelletier article on caffeine is the first to use the term in print (in French form CafÃÆ'Â © ine from the French word for coffee: cafÃÆ'Â © ). This corroborates Berzelius's account:
Caffeine, noun (feminine). The crystallized substances found in coffee in 1821 by Mr. Robiquet. During the same period - when they were looking for quinine in coffee because coffee was considered by some doctors as a drug that reduced the fever and because of the family-owned coffee that is similar to the quinine tree [quinine] - on their part, Mr. Pelletier. and Caventou received caffeine; but because their research has a different purpose and because their research is not done yet, they leave a priority on this subject to Mr. Robiquet. We do not know why Mr. Robiquet has not published the coffee analysis he read at the Pharmacy Society. This publication will allow us to make caffeine better known and give us accurate ideas about coffee composition...
Robiquet was one of the first to isolate and explain the properties of pure caffeine, while Pelletier was the first to perform elemental analysis.
In 1827, M. Oudry isolated the "thÃÆ' Ã… © ine" from tea, but later proved by Mulder and by Carl Jobst that theine is actually the same as caffeine.
In 1895, German chemist Hermann Emil Fischer (1852-1919) first synthesized caffeine from its chemical components (ie "total synthesis"), and two years later, it also obtained the structural formula of the compound. This is part of the work that Fischer was awarded the Nobel Prize in 1902.
Historical rules
Because it is recognized that coffee contains some compounds that act as stimulants, coffee first and then also caffeine is sometimes subject to regulation. For example, in the 16th century Islamists in Mecca and in the Ottoman Empire made illegal coffee for some classes. Charles II of England tried to ban it in 1676, Frederick II of Prussia banned it in 1777, and coffee was banned in Sweden at various times between 1756 and 1823.
In 1911, caffeine became the focus of one of the earliest documented health threats, when the US government seized 40 barrels and 20 Coca-Cola syrup syrup in Chattanooga, Tennessee, accusing caffeine in its drink "harmful to health". Although the judge ruled in favor of Coca-Cola, two draft laws were introduced to the US House of Representatives in 1912 to amend the Food and Pure Drug Act, adding caffeine to the list of "habitual" and "destructive" substances, which should be listed on product labels.
Society and culture
Rule
The Food and Drug Administration (FDA) in the United States currently allows only drinks containing less than 0.02% caffeine; but caffeine powder, which is sold as a dietary supplement, is not regulated. It is a regulatory requirement that most packaged food labels should state the list of ingredients, including food additives such as caffeine, in descending order of proportion. However, there are no regulatory requirements for quantitative labeling of caffeine, (eg, milligrams of caffeine per portion of the stated size). There are a number of foods that naturally contain caffeine. These ingredients should appear in the list of groceries. However, as for "food additive caffeine", there is no requirement to identify quantitative quantities of caffeine in composite foods containing natural ingredients that are sources of caffeine. While coffee or chocolate is widely recognized as a source of caffeine, some ingredients (eg, guarana, yerba matà ©  ©) tend to be less recognized as a source of caffeine. For the natural sources of caffeine, there is no regulatory requirement that requires food labels to identify the presence of caffeine or to declare the amount of caffeine present in the diet.
Consumption
Global consumption of caffeine is estimated at 120,000 tons per year, making it the most popular psychoactive substance in the world. This amounts to one serving of caffeinated beverages for each person every day.
Religion
Some Seventh Day Adventists, Lord's Church Officials (Recovery), and Christian Scientists do not consume caffeine. Some of these religions believe that one should not consume non-medical, psychoactive substances, or believe that one should not consume an addictive substance. The Church of Jesus Christ of Latter-day Saints has said the following in relation to caffeinated beverages: "... the revelation of the Church that spelled out health practice (Doctrine and Covenants 89) does not mention the use of caffeine.Christmas Guidelines prohibit alcoholic beverages, smoking or chewing tobacco, and 'hot drinks' - are taught by Church leaders to refer specifically to tea and coffee. "
Gaudiya Vaishnavas generally also abstain from caffeine, because they believe it obscures the mind and stimulates feelings in excess. To be initiated under a teacher, one must not have caffeine, alcohol, nicotine or other drugs, at least for a year.
Caffeinated drinks are widely consumed by Muslims today. In the 16th century, some Muslim rulers made an unsuccessful attempt to ban them as "intoxicating drinks" that were banned under Islamic dietary laws.
Other organisms
Newly discovered bacteria Pseudomonas putida CBB5 can live with pure caffeine and can break down caffeine into carbon dioxide and ammonia.
Caffeine is poisonous to birds and dogs and cats, and has adverse effects on mollusks, insects, and spiders. This is at least in part due to poor ability to metabolize compounds, leading to higher rates for specific doses per unit of weight. Caffeine has also been found to enhance the memory of honeybee prizes.
Research
Caffeine has been used to multiply chromosomes in haploid grain.
See also
- Promotional agents active
- Nootropic
References
Bibliography
- Bersen I (1999). Coffee, Sex & amp; Health: History of anti-coffee crusaders and sexual hysteria . Sydney: Helian Books. ISBN 978-0-9577581-0-0.
- Pendergrast M (2001) [1999]. Uncommon Land: The History of Coffee and How It Changes Our World . London: Texere. ISBNÃ, 1-58799-088-1.
External links
- GMD MS Spectrum
- Consumer Union Report on Drugs and Dark, Caffeine-Part 1 Part 2
- Caffeine: ChemSub Online
- Caffeine in the Periodic Video Table (University of Nottingham)
- International Caffeine Chemical Security Card
- Mayo Clinic staff (October 3, 2009). "Caffeine content for coffee, tea, soda, and more". Mayo Clinic . Retrieved November 8 2010 .
Source of the article : Wikipedia
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