Healthy Energy (Part 3 – Facts about Fatigue)

“Fatigue may be defined as a subjective state in which one feels tired or exhausted, and in which the capacity for normal work or activity is reduced.”

Everyone experiences fatigue occasionally. It is the body’s way of signaling its need for rest and sleep. But when fatigue becomes a persistent feeling of tiredness or exhaustion that goes beyond normal sleepiness, it is usually a sign that something more serious is amiss.

Physically, fatigue is characterized by a profound lack of energy, feelings of muscle weakness, and slowed movements or central nervous system reactions. Fatigue can also trigger serious mental exhaustion. Persistent fatigue can cause a lack of mental clarity (or feeling of mental “fuzziness”), difficulty concentrating, and in some cases, memory loss.

There is, however, no commonly accepted definition of fatigue when it is considered in the context of health and illness. This lack of definition results from the fact that a person’s experience of fatigue depends on a variety of factors. These factors include culture, personality, the physical environment (light, noise, and vibration), availability of social support through networks of family members and friends, the nature of a particular fatiguing disease or disorder, and the type and duration of work or exercise. The experience of fatigue associated with disease will be different for someone who is clinically depressed, is socially isolated, and is out of shape, as compared to another person who is not depressed, has many friends, and is aerobically fit.

Some researchers regard fatigue as a defense mechanism that promotes the effective regulation of energy expenditures. According to this theory, when people feel tired they take steps to avoid further stress (physical or emotional) by resting or by avoiding the stressor. They are then conserving energy. Since chronic fatigue is not normal, however, it is a common symptom of some mental disorders, a variety of physical diseases with known etiologies (causes), and medical conditions that have no biological markers although they have recognizable syndromes (patterns of symptoms and signs).

Fatigue is sometimes described as being primary or secondary. Primary fatigue is a symptom of a disease or mental disorder, and may be part of a cluster of such symptoms as pain, fever, or nausea. As the disease or disorder progresses, however, the fatigue may be intensified by the patient’s worsening condition, by the other disease symptoms, or by the surgical or medical treatment given to the patient. This subsequent fatigue is called secondary.

Fatigue is a common experience. It is one of the top ten symptoms that people mention when they visit the doctor. Some people, however, are at higher risk for developing fatigue. The risk for women is about 1.5 times the risk for men, and the risk for people who do not exercise is twice that of active people. Some researchers question whether women really are at higher risk, since women are more likely than men to go to the doctor with health problems; also, men are less likely to admit they feel fatigued. Other risk factors include obesity, smoking, use of alcohol, high stress levels, depression, anxiety, and low blood pressure. Having low blood pressure is usually considered desirable in the United States, but is regarded as a treatable condition in other countries. Low blood pressure or postural hypotension (sudden lowering of blood pressure caused by standing up) may cause fatigue, dizziness, or fainting.

The management of fatigue depends in large measure on its causes and the person’s experience of it. For example, if fatigue is acute and normal, the person will recover from feeling tired after exertion by resting. In cases of fatigue associated with influenza or other infectious illnesses, the person will feel energy return as they recover from the illness. When fatigue is chronic and abnormal, however, the doctor will tailor a treatment program to the patient’s needs. There are a variety of approaches that include:

· Aerobic exercise. Physical activity increases fitness and counteracts depression.

· Hydration (adding water). Water improves muscle turgor, or tension, and helps to carry electrolytes.

· Improving sleep patterns. The patient’s sleep may be more restful when its timing and duration are controlled.

· Pharmacotherapy (treatment with medications). The patient may be given various medications to treat physical diseases or mental disorders, to control pain, or to manage sleeping patterns.

· Psychotherapy. There are several different treatment approaches that help patients manage stress, understand the motives that govern their behavior, or change maladaptive ideas and negative thinking patterns.

· Physical therapy. This form of treatment helps patients improve or manage functional impairments or disabilities.

Source: http://www.answers.com/fatigue?cat=health

“A stimulant is any substance that causes an increase in activity in various parts of the nervous system or directly increases muscle activity.”

Cerebral, or psychic, stimulants act on the central nervous system and provide a temporary sense of alertness and well-being as well as relief from fatigue. Drugs such as caffeine and the amphetamines belong in this category, and several groups of drugs chemically similar to antihistamines and phenothiazines also act as mild psychic stimulants (see psychopharmacology). Cocaine, besides its effect as a local anesthetic, also stimulates the central nervous system, producing excitement and erratic behavior. The hallucinogenic drugs are also central nervous system stimulants.

A second class of stimulants that affect the medulla and spinal cord includes derivatives of niacinamide (nicotinic acid amide) and other chemically diverse compounds; they are sometimes used to speed the return to wakefulness after anesthesia or to counteract barbiturate poisoning. Ammonia, in smelling salts, is also a medullary stimulant; the alkaloid strychnine is a spinal-cord stimulant.

Other substances act mainly on the autonomic nervous system. Drugs that stimulate the parasympathetic portion of the autonomic nervous system, such as pilocarpine, physostigmine, and neostigmine, cause contracted pupils, salivation and sweating, slowed heartbeat, and lowered blood pressure. Drugs such as norepinephrine, epinephrine, and other catecholamines and synthetic analogs stimulate the sympathetic portion of the autonomic nervous system, resulting in dilated pupils, rapid heartbeat, and increased blood pressure. Because the sympathetic and parasympathetic systems have opposing physiological effects, stimulation of one system amounts to depression of the other. Some of the alkaloids from the ergot fungus act by direct stimulation of smooth muscle, inducing contractions in uterine and intestinal muscle.

Source: http://www.answers.com/topic/stimulant?nr=1&lsc=true&cat=health

“Adrenaline increases heart rate, the depth and rate of breathing, and metabolic rate.”

Also known as epinephrine. The so-called ‘fight or flight’ hormone secreted by the inner part of the adrenal gland. It prepares the body for action by its stimulatory effects on muscles, circulation, and carbohydrate and fat metabolism. Adrenaline increases heart rate, the depth and rate of breathing, and metabolic rate. It also improves the force of muscular contractions and delays the onset of fatigue. Its actions oppose those of insulin. Adrenaline accelerates fat mobilization and encourages the conversion of glycogen to glucose.

Adrenaline and adrenaline-related drugs are sometimes used in sport as stimulants. Although these drugs can improve performance, they may produce harmful side-effects such as heart beat irregularities. Consequently, they are on the International Olympic Committee’s list of banned substances.

Source: http://www.answers.com/topic/adrenaline?cat=health

“Foods and drinks (and other substances) that stimulate the consumer to enhanced mental alertness, increased or prolonged physical activity, uninhibited conviviality, or fierce fighting are called “stimulants.””

This definition is intentionally a narrow one. It excludes the great majority of nourishing foods, for example, because a nourishing meal in itself produces, alongside a feeling of well-being, somnolence (sleepiness) rather than alertness and activity. It also excludes substances such as cannabis and opium (both occasionally taken as foods) that depress mental and physical activity: these are sedatives, not stimulants.

We must distinguish enhanced mental alertness from hallucination, the tendency to see what isn’t there; hallucinogens are, therefore, also excluded. Other exclusions include appetizers, which stimulate the appetite for food, and aphrodisiacs, which (to the extent that such foods really exist) stimulate sexual appetites and energies.

Using foods that have a stimulant effect provides ways of intentionally adjusting the body’s metabolism, which carries risks. There is a good reason why a nourishing meal produces sleepiness: after such a meal, the body is occupied with digestion. Postponing or interrupting that activity may produce digestive disturbance. In any case, increased alertness and physical activity will eventually be paid for in greater-than-usual exhaustion, and there may be other undesirable aftereffects. For example, it may be necessary to compensate for the aftereffects of stimulants by using them again. If the desired effect lessens after frequent use, increased quantities might be needed. In this way, regular use turns into dependence and addiction.

It is even more true of stimulants than of foods in general that their use is not independent of its social context, but no simple generalization is possible. Some of the foods discussed here are nearly always taken in company, as part of a social ritual. Some are nearly always taken as part of, or immediately before or after, a meal. Some, however, are customarily taken when one is not in company and not eating a meal; such habits may vary from one culture to another. External observers focusing on individual psychology may see the solitary use of stimulant foods as posing a personal, social, or criminal problem, while social use might be perceived as no problem or as a different kind of problem. Furthermore, observers focusing on social groups will find users of these stimulant foods to be unexpectedly protective, even nationalistic, about the preferred means of preparing them, which may vary widely.

Stimulant foods have been identified, like nearly all other foods and like many thousands of medicinal plants, in the course of very long-term unrecorded experiments: each human community explores its environment, notes animals and plants that may be of use, finds ways to use them, sometimes begins to farm them, and to trade in them. The stimulant effects of these foods were discovered empirically, as were their associated side-effects and dangers. In the last two centuries, chemists and nutrition scientists have identified their active constituents, making possible for the first time a scientific explanation of their effects.

In general, stimulant foods and drinks are either taken in a neutral vehicle, such as hot water, or they are slowly extracted by chewing. Nonfood stimulants are often taken as smoke or snuff. These various methods all ensure gradual absorption with relatively little interference from other foods. Alcoholic drinks are unusual because they are frequently taken without admixture and often contain strong flavorings: however, water is the principal constituent of most alcoholic drinks, and more water is often added.

Most traditional cultures had one, or at the most two, familiar stimulants. Globalization has changed this, producing such effects as the worldwide fashion for coffee; the worldwide marketing of chocolate, instant coffee, and the “cola” drinks; and the complex social interplay between alternative stimulants of almost equal status, neatly symbolized by the ritual question at breakfast in a French hotel, “Café? Thé? Chocolat?” (Coffee? Tea? Hot chocolate?)

Caffeine

Caffeine is among the commonest of stimulants worldwide. It is the chief active constituent in coffee and tea, which are familiar in practically every country, and in maté, guaraná, and cola nut, which are popular in South America and West Africa. It is present in smaller quantities in some other stimulant foods, including chocolate.

Coffee. Coffee consists of the roasted, ground beans of Coffea arabica. Native to Ethiopia, its use spread in late medieval times to Yemen; from there it rapidly became popular around the Mediterranean. Both Arabs and Europeans encouraged its further spread. Details of its use vary. Boiling water is added; commonly sugar is used as a flavoring, and sometimes milk or cream. Often coffee is drunk after meals, but it is also often taken between meals, both by groups as a social drink and by workers as a stimulant. Several substances have been used as coffee substitutes. Most of them had the advantages of being cheap and of tasting somewhat like coffee but the disadvantage of containing little or no caffeine. These substitutes have now been overtaken in popularity by instant coffee, a soluble product manufactured from the beans of Coffea robusta, which does contain caffeine.

Tea. Tea is made from the dried leaves of Camellia sinensis, native to southern China. The use of tea was already spreading beyond China in the ninth century; like coffee, it became popular in Europe in the seventeenth century and its use then spread worldwide. Again, like coffee, details of its use vary. Boiling water is usually poured onto the leaves, which are then allowed to steep for a few minutes. The resulting liquid is much lighter in flavor and color than coffee. Some add sugar to it: fewer, notably the British, add milk; some drink it iced. Tea is more often taken between meals than during meals; like coffee, it is used both as a social drink and by workers as a stimulant.

Caffeine beverages in South America. Maté, also called Paraguayan tea, is made by pouring boiling water onto the dried and roasted leaves of yerba maté (Ilex paraguariensis). Most of the leaves that are used come from wild trees gathered from the forests of southern South America. Maté is traditionally a social drink, made in a gourd or a silver pot and sucked through a shared straw or silver tube. It is drunk while still extremely hot, so added pleasure is provided by watching the reactions of unskillful foreigners who burn their lips and mouths while trying to drink it. It is usually taken without sugar, but sometimes orange zest is added as a flavoring. Maté is the national beverage of Argentina and Paraguay but has never spread beyond the region. The plant is a relative of European holly (Ilex aquifolium), whose leaves have occasionally been used to make a narcotic drink; more importantly, it is related to yaupon or Carolina tea (Ilex vomitoria) and other species that have been used to make stimulating and narcotic drinks by North Americans both before and after European settlement.

Guaraná (Paullinia cupana) is a tropical plant native to Brazil. Its seeds are traditionally roasted, pounded, and made into cakes called “Brazilian chocolate.” They have this name not because they can be eaten solid, like modern chocolate bars, but because in pre-Columbian Mexico travelers used to carry similar cakes of powdered cacao for use in making an instant chocolate drink. Like those, cakes of guaraná are traditionally crumbled into water by tired travelers in Brazil, making a stimulating drink particularly rich in caffeine. Guaraná is now also used as a flavoring for soda, candy, and liqueurs.

Caffeine in Africa. The cola nut, a rich source of caffeine, is the usual native stimulant of West and Central Africa. It might rather be called a seed, since eight or ten of them are found in each fruit of the trees Cola nitida and C. acuminata. These seeds are white, pink, or red: the white ones are said to be the best. They are customarily chewed before meals: they have a bitter flavor but, perhaps as a result of this, foods and drinks taken afterwards seem sweet (water, taken after cola, tastes “like white wine and sugar,” according to one observer). Apart from this effect as an appetizer, cola nuts have a high reputation among their traditional users, as stimulant, digestive, and aphrodisiac. Alongside caffeine, they contain theobromine (as does chocolate) and kolanin, a heart stimulant. Cola nuts can also be ground into powder and mixed with water as a drink, and cola extract is used to flavor sodas and candies: the names of Coca-Cola and Pepsi-Cola allude to cola nuts, which may well be an ingredient in these products.

Theobromine

Theobromine is the chief active ingredient in cacao beans, the seeds of the tropical tree Theobroma cacao. These beans, fermented, roasted, and ground, are the raw material for chocolate, the traditional stimulant of Mexico, familiar worldwide. In pre-Columbian civilizations, chocolate was used as a drink: the ground cacao was mixed into hot water, which was then poured from a height into the serving cup to produce the much-desired foam. Flavors (chili, vanilla, or others) and color (notably annatto) might be added. Popularized in Europe by the Spanish, chocolate became successively a sugary drink and a milky drink; many other flavorings were tried, including the cinnamon now favored in Mexico. Eventually (in the nineteenth century) chocolate was made into bars to be eaten solid, and in many countries this is now its most familiar form. In the Maya and Aztec civilizations, chocolate was a social drink, taken after dinner, serving as a stimulant (and, according to some, an aphrodisiac). Whole chocolate contains caffeine as well as theobromine, and it is also rich in cocoa butter, making it an extremely nourishing food and, therefore, unlikely to produce aftereffects such as exhaustion.

Nicotine

Tobacco, the fermented leaf of Nicotiana tabacum, is usually smoked; in that form it cannot be classified as a food. It can be chewed, however. In Western cultures, chewed tobacco has been typical of sailors and other manual workers subjected to extreme weather conditions that make smoking difficult. Tobacco’s active ingredient, nicotine, a deadly poison in the pure state, acts as a stimulant when slowly absorbed.

In Australia, another plant, Duboisia hopwoodii, has leaves and flowers very rich in nicotine. Aborigines dry and grind the leaves, mix them with the ash of certain other plants, and roll them into balls, called “pituri,” for chewing. These are used by solitary workers and travelers as a stimulant to stave off tiredness and hunger; they are also exchanged as a sign of friendship. They are, or were, used by warrior groups in preparation for a battle. There is a definite advantage in chewing ash in pituri (and also with coca and betel nut), because alkalis in the ash detach the active stimulant substance, in this case nicotine, from the plant acids, allowing it to be more rapidly absorbed. The use of ash in this way has developed, apparently independently, in Australia, southeastern Asia, and South America.

Cocaine

Coca is the dried leaf of a plant species native to western South America, Erythroxylum coca, and of a second species, E. novogranatense, which developed under cultivation. Coca leaves were known as a stimulant to the pre-Columbian peoples of the Andean region, and continued to be used by them and their Spanish conquerors. Their use is extremely widespread in South America. As with the nicotine plants, the principal use of coca leaves has been as a stimulant for workers and travelers. The usual way is to take some leaves, mix them with the ash of burnt coca or another wood, roll the mixture into a ball, and chew it. Coca leaves, like chocolate, are really nourishing, a property that tends to reduce the severity of the exhaustion that usually follows the use of stimulants. The active constituent of coca leaves was isolated (and named cocaine) in 1860. When taken in the pure form, cocaine was found to be a useful medicinal drug but also highly addictive. It was among the first stimulants to arouse strong medical and governmental disapproval. In the early twentieth century, many countries made it illegal. The name of Coca-Cola alludes to coca, and the early recipe for the product contained cocaine, like other soft drinks of the period.

Some other species of genus Erythroxylum contain cocaine or similar compounds and are used as stimulants by various South American peoples: E. cataractum by the Cubeo of Colombia; E. fimbriatum and E. macrophyllum by the Bora and Huitoto of Peru.

Other Stimulants

Betel. The commonest traditional stimulant of southern and southeastern Asia is betel. Like pituri and coca, betel is customarily made up as a chewing packet that includes ash. The active ingredient, arecoline, is contained in the areca nut or betel nut (the nut of the palm Areca catechu), which is cut into long narrow pieces and placed inside the packet along with a “lime” made from burnt coral and oyster shells. The packet is formed from a leaf of the betel pepper vine (Piper betle). In traditional households, the betel chews are made up each day from fresh supplies; as with pituri, it is a sign of friendship and hospitality to offer a chew to any visitor. The habitual chewing of betel eventually stains the mouth red and the teeth black. When it is first tried, betel can produce feelings of anxiety, excitement, and vertigo; to those who use it regularly, it is a mild stimulant.

Khat. Coffee, when it was introduced to Yemen from across the Red Sea, was not the country’s first stimulant. That position belongs to khat (or qat), the leaf of Catha edulis. Khat is used in Yemen, Saudi Arabia, and a large area of East Africa from Ethiopia and Somalia to Mozambique and South Africa. It had not spread outside the region until some Americans acquired the taste for it while they were in Somalia with United Nations troops during the early 1990s. Khat is often taken as a tea, made by pouring boiling water onto the dried or fresh leaves. Fresh leaves can also be chewed; in this form its effect is said to be stronger than coffee but not as strong as alcohol. When chewed, khat is often used socially because it enlivens conversation. The principal active constituent in khat is cathinone, now classified as an illegal drug in the United States; however, cathinone is only present in fresh leaves. The second active constituent, cathine, which is still present in the dried leaves, is an appetite suppressant.

A milder stimulant of the same general type is Mormon tea, the leaf of Ephedra nevadensis. These leaves contain the active ingredient pseudoephedrine, and are made into a tea with boiling water.

Kava. The root of the plant kava-kava, Piper methysticum, is the source of kava, a familiar stimulant used in Hawaii and other Pacific islands. The fresh root is chopped or ground and then soaked and squeezed in water to produce a milky, spicy liquid, which is traditionally served in half coconut shells. Kava is a social drink whose effect is to produce a condition physically resembling drunkenness, though with apparent clarity of mind. The principal active constituents are known as kavalactones.

Kratom. Kratom, a stimulant indigenous to Thailand and little known elsewhere, consists of the leaves of Mitragyna speciosa. These leaves can be smoked or made into a tea. The active constituent is mitragynine, which, like cocaine, is a stimulant at low doses but a narcotic at higher doses.

Alcohol

Alcohol is an atypical stimulant because it is not naturally present in any fresh plant. It is produced from the fermentation by yeast of plant sugars. One starting point is a fruit juice. Grape juice makes wine; apple juice makes (hard) cider; pear juice makes perry. Several other fruits are used in various parts of the world. A second starting point is malted cereal: barley is the commonest choice, and the result is beer. Plant saps can be used if they contain sufficient sugar: liquid cane sugar is so used in India, while pulque, a Mexican alcoholic drink, is made from the sap of the maguey (Agave atrovirens). Finally, honey, mixed with water, can be used, and the result is mead (a beverage that figures importantly in the Old English epic Beowulf ). There are two common adjustments to the process: adding cane or beet sugar to the original juice gives the yeast more raw material to work with, producing more alcohol; distilling the final product achieves much greater concentrations of alcohol, resulting in “hard liquor.”

Wine and beer are both ancient inventions, going back to southwestern Asia several thousand years B.C.E. But yeasts are naturally present in the air; therefore, alcoholic drinks might have been invented or discovered many times in human history; certainly, the origin of pulque is independent of those of wine and beer.

Alcoholic drinks have most generally, in traditional societies, been used as social drinks, and they have commonly been used in a ritualistic way as well. Their production is linked with the seasons (in general the required juices are available only when fruit is ripe, and the fermentation process takes time); therefore, by contrast with most other stimulants, the discovery of alcoholic drinks and the annual vintage (especially of wine) tend to be celebrated in major festivals. In many cultures, the ordinary, everyday consumption of alcohol follows precise rules, tending to ensure, for example, that everyone drinks equally. Both in the major festivals and in everyday social drinking, it is commonly the case that drunkenness is aimed at, at least to the extent of the loss of inhibitions, but sometimes going all the way to unconsciousness.

Like kava—and unlike many stimulants—alcohol tends to produce enhanced mental activity accompanied by physical incapacity. In traditional societies, travelers used coca, maté, guaraná, pituri, and other stimulants to keep them going; they would not use alcohol or kava till they had arrived. Likewise, coffee, tea, and some similar stimulants may enhance one’s ability to drive safely, for a certain period, while kava and alcohol impair it.

Source: http://www.answers.com/topic/stimulant?nr=1&lsc=true&cat=health

“Alcohol is no great friend to the athlete, nor is it to those on a weight-loss diet. Each gram of pure alcohol provides 7 Calories (7000 calories) of energy.”

In medicine, it is used as a tincture and antiseptic but its greatest use is in drinks. It is quickly absorbed into the bloodstream from the mouth cavity and stomach. After absorption, it acts as a depressant on the central nervous system. This may have the beneficial effect of reducing feelings of fatigue but it also reduces judgement, self-control, and concentration. Reactions are slowed by alcohol and muscular coordination is impaired. Alcohol also acts as a diuretic, stimulating the kidneys to eliminate more urine which can result in dehydration.

In addition, alcoholic beverages often contain sugar and other nutrients, increasing their calorific value. A single measure of spirits contains about 50 Calories, and one pint of lager contains about 170 Calories. Drinking too much alcohol can lead to obesity because some is converted to fat. Despite its relatively high energy content, alcohol is a poor energy source compared with carbohydrate because it cannot be used directly by muscles, and because of its adverse effects. Before it can be used by heart muscle and skeletal muscle, alcohol has to be broken down in the liver to acetate or acetaldehydes. The breakdown is relatively slow which is why alcohol can remain in the bloodstream for several hours. Alcohol can also inhibit the conversion of glycogen to glucose in the liver. If it is ingested during prolonged exercise it can increase the likelihood of hypoglycaemia (abnormally low blood sugar).

Moderate drinking has not been linked to any significant health problems. On the contrary, several studies have shown that it can be beneficial and may reduce the risk of coronary heart disease by preventing platelets in the blood from sticking together. However, chronic, heavy drinking is a significant health risk: it can shrink the brain; it irritates the stomach and small intestine, resulting in malabsorption and deficiencies of vitamins and minerals; it can damage the liver and cause cirrhosis; and it can adversely affect the cardiovascular system, increasing the risk of heart attacks. Heavy drinking is not compatible with a healthy, active lifestyle.

Alcoholism is a major cause of malnutrition. The reasons are threefold. First, alcohol interferes with central mechanisms that regulate food intake and causes food intake decreases. Second, alcohol is rich in energy (7.1 kcal/g), and like pure sugar most alcoholic beverages are relatively empty of nutrients. Increasing amounts of alcohol ingested lead to the consumption of decreasing amounts of other foods, making the nutrient content of the diet inadequate, even if total energy intake is sufficient. Thus chronic alcohol abuse causes primary malnutrition by displacing other dietary nutrients. Third, gastrointestinal and liver complications associated with alcoholism also interfere with digestion, absorption, metabolism, and activation of nutrients, and thereby cause secondary malnutrition.

It is important to note that although ethanol is rich in energy, its chronic consumption does not produce the expected gain in body weight. This may be attributed, in part, to damaged mitochondria and the resulting poor coupling of oxidation of fat metabolically utilizable with energy production. The microsomal pathways that oxidize ethanol may be partially responsible. These pathways produce heat rather than adenosine triphosphate (ATP) and thereby fail to couple ethanol oxidation to useful energy-rich intermediates such as ATP. Thus, perhaps because of these energy considerations, alcoholics with higher total caloric intake do not experience expected weight gain despite physical activity levels similar to those of the non-alcohol-consuming overweight population.

Source: http://www.answers.com/Alcohol?nr=1&lsc=true&cat=health

“Despite its presence in many energy drinks, taurine has not been shown to be energy-giving, however the results of the studies into taurine usage have shown that taurine might help to reduce muscle fatigue.”

In recent years, taurine has become a common ingredient in energy drinks. Taurine is often used in combination with bodybuilding supplements such as creatine and anabolic steroids, partly due to recent findings in mice that taurine alleviates muscle fatigue in strenuous workouts and raises exercise capacity. Taurine is also used in some contact lens solutions.

Taurine has also been shown in diabetic rats to decrease weight and decrease blood sugar.

Taurine is conjugated via its amino terminal group with the bile acids chenodeoxycholic acid and cholic acid to form the bile salts sodium taurochenodeoxycholate and sodium taurocholate (see bile). The low pKa (1.5) of taurine’s sulfonic acid group ensures that this moiety is negatively charged in the pH ranges normally found in the intestinal tract and thus improves the surfactant properties of the cholic acid conjugate. Taurine is the only known naturally occurring sulfonic acid.

Taurine has also been implicated in a wide array of other physiological phenomena including inhibitory neurotransmission, long-term potentiation in the striatum/hippocampus, membrane stabilization, feedback inhibition of neutrophil/macrophage respiratory bursts, adipose tissue regulation, and calcium homeostasis.

Recent studies show that taurine supplements taken by mice on a high-fat diet prevented them from becoming overweight. Studies have yet to be done on the effect of taurine on obesity in humans. Currently taurine is being tested as an anti-manic treatment for bipolar depression. Recent studies have also shown that taurine can influence (and possibly reverse) defects in nerve blood flow, motor nerve conduction velocity, and nerve sensory thresholds in experimental diabetic neuropathic rats. Taurine levels were found to be significantly lower in vegans than in a control group on a standard American diet. Plasma taurine was 78% of control values, and urinary taurine 29%.

Taurine is named after the Latin taurus, which means bull, as it was first isolated from ox bile in 1827 by Austrian scientists Friedrich Tiedemann and Leopold Gmelin. It is often called an amino acid, even in scientific literature, but as it lacks a carboxyl group it is not strictly an amino acid. It does contain a sulfonate group and may be called an amino sulfonic acid. Small polypeptides have been identified which contain taurine but to date no aminoacyl tRNA synthetase has been identified as specifically recognizing taurine and capable of incorporating it onto a tRNA. Also, while taurine is present in both bull semen and urine, the taurine used in energy drinks such as Red Bull is not taken from these sources.

Source: http://www.answers.com/Taurine