'''Choline'''isa[[nutrient]], essential for [[cardiovascular]] and [[brain]] function, and for [[cellular membrane]] composition and repair.
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| Section1 = {{Chembox Identifiers
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| CASNo = 62-49-7
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| PubChem = 305
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| MeSHName = Choline
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| Section2 = {{Chembox Properties
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| Formula = C5H14NO+
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| MolarMass = 104.171
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| Section3 = {{Chembox Hazards
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'''Choline''' is an [[organic compound]], classified as an [[essential nutrient]]<ref>{{pauling|id=othernuts/choline/|title=Choline|author=Jane Higdon}}</ref><ref>"[http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/cho_0283.shtml Choline], ''PDRHealth''</ref><ref>"[http://www.abc.net.au/rn/talks/8.30/helthrpt/stories/s119524.htm Choline]" (An interview with Steven Zeisel, Editor-in-Chief of the Journal of Nutritional Biochemistry), ''Radio National Health Report with Norman Swan'', Monday 17 April 2000</ref> and usually grouped within the [[Vitamin B]] complex. This natural [[amine]] is found in the lipids that make up cell membranes and in the [[neurotransmitter]] [[acetylcholine]]. Adequate intakes (AI) for this [[micronutrient]] of between 425 to 550 milligrams daily, for adults, have been established by the Food and Nutrition Board of the [[Institute of Medicine]] of the [[United States National Academy of Sciences|National Academy of Sciences]].
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==History==
==History==
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Choline was discovered by Andreas Strecker in [[1862]] and [[chemical synthesis|chemically synthesized]] in [[1866]]. In [[1998]] choline was classified as an [[essential nutrient]] by the [[Food and Nutrition Board]] of the [[Institute of Medicine]] (U.S.A.) and [[Dietary Reference Intake|Adequate Intakes]] (AI) have been established.
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Choline was discovered by Andreas Strecker in [[1864]] and [[chemical synthesis|chemically synthesized]] in [[1866]]. In [[1998]] choline was classified as an [[essential nutrient]] by the [[Food and Nutrition Board]] of the [[Institute of Medicine]] ([[United States|U.S.A.]]).
==Chemistry==
==Chemistry==
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'''Choline''' is a [[quaternary ammonium cation|quaternary]] [[saturation (chemistry)|saturated]] [[amine]] with the [[chemical formula]]
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'''Choline''' is a [[quaternary ammonium cation|quaternary]] [[saturation (chemistry)|saturated]] [[amine]] with the [[chemical formula]]: ([[methyl|CH<sub>3</sub>]])<sub>3</sub>[[Nitrogen|N]]<sup>+</sup>[[methylene|CH<sub>2</sub>]][[methylene|CH<sub>2</sub>]][[hydroxyl|OH]]X<sup>−</sup>.
where X<sup>−</sup> is a [[counterion]] such as [[chloride]] (see [[choline chloride]]), [[hydroxyl|hydroxide]] or [[Tartaric acid|tartrate]].
where X<sup>−</sup> is a [[counterion]] such as [[chloride]] (see [[choline chloride]]), [[hydroxyl|hydroxide]] or [[Tartaric acid|tartrate]].
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[[Choline chloride]], in mixture with [[urea]] is used as a solvent ( [[deep eutectic solvent|DES]] ) .
==Physiology==
==Physiology==
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Choline and its [[metabolites]] are needed for 3 main physiological purposes: structural integrity and signaling roles for cell membranes, cholinergic [[neurotransmission]] ([[acetylcholine]][[proteinbiosynthesis|synthesis]]),andasa major source for [[methyl groups]] via its metabolite, [[trimethylglycine]](betaine) that participates in the [[S-adenosylmethionine]] synthesis [[metabolic pathway|pathways]].
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[[Image:Choline_metabolism.png|thumb|300px|right|Cholinemetabolism. (Cholineisgreenboxatleft, secondfrom the bottom.)]]
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Choline and its [[metabolites]] are needed for three main [[physiology|physiological]] purposes: structural integrity and [[cell signaling|signaling]] roles for cell membranes, cholinergic [[neurotransmission]] ([[acetylcholine]] [[protein biosynthesis|synthesis]]), and as a major source for [[methyl group]]s via its metabolite, [[trimethylglycine]] (betaine) that participates in the [[S-adenosylmethionine]] synthesis [[metabolic pathway|pathways]].
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When choline is metabolized by the body, it may form [[trimethylamine]], a compound with a fishy odor. Hence, when large amounts of choline are taken (such as 10-16 grams/day as a [[dietary supplement]]), the person may suffer from a fishy [[body odor]].
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When choline is [[metabolism|metabolized]] by the [[body]], it may form [[trimethylamine]], a compound with a fishy odor. Hence, when large amounts of choline are taken the person may suffer from a fishy [[body odor]].
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==Choline as a Supplement==
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==Choline as a supplement==
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The [[FoodandDrugAdministration]] (FDA)requires[http://www.fda.gov/fdac/features/596_baby.html] thatinfantformulabemadefromcow'smilkcontaining choline.
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It is well established that supplements of methyl group transfer vitamins [[vitaminB6|B6]],[[vitaminB12|B12]],[[folic acid]] reduce the [[blood]] [[titer]] of [[homocysteine]] and prevent [[cardiovascular disease|heart disease]]. Choline is a necessary source of methyl groups for methyl group transfer. Supplements of [[lecithin]]/choline by Central Soya scientists reduced heart disease in [[clinical trial|laboratory studies]]. The reduction in heart disease with lecithin supplements may however relate more to the [[cholesterol]] carryingcapacityoflecithinthantothemethylgroup transfer role of choline.{{Specify|date=December 2006}}
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Choline hasalsofounditswayintonutritionalsupplementswhichclaim to reduce [[adiposetissue|bodyfat]];butthere is little or noevidence to prove that it hasanyeffectonbodyfatwhatsoever.
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Choline supplementsareoftentakenasaformof'smartdrug' or [[nootropic]], due to the role that the neurotransmitter [[acetylcholine]]playsin various [[cognition]] systemswithin the brain. Choline is a chemical precursor or "buildingblock" needed to produce the neurotransmitter acetylcholine, and research suggests that memory, intelligence and mood are mediated at least in part by acetylcholine metabolism in the brain. The compound's [[quaternary amine]] renders it lipidinsoluble and theoretically unable to cross the [[blood-brain barrier]]. However, despite choline's lipid insolubility, a choline transporter exists that allows transport across the blood-brain barrier. The efficacy of these supplements in enhancing cognitive abilities isatopicofcontinuingdebate.
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Some people who practice lucid dreaming use Galantamine with Choline to increase their odds of having a Lucid dream.
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The [[Food and Drug Administration]] (FDA) requires that [[infant formula]] be made from cow's [[milk]] containing choline.<ref>Isadora B. Stehlin, "[http://www.fda.gov/fdac/features/596_baby.html Infant Formula: Second Best but Good Enough]", ''U.S. Food and Drug Administration''.</ref>
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Due to its role in [[lipid metabolism]], choline has also found its way into nutritional supplements which claim to reduce [[adipose tissue|body fat]]; but there is little or no [[scientific evidence|evidence]] to prove that it has any effect on reducing excess body fat or that taking high amounts of choline will increase the rate at which fat is metabolised.
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==Fish Odor Syndrome==
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:''Main article: [[Trimethylaminuria]]''
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Choline is a precurser to [[trimethylamine]], which some persons are not able to break down due to a genetic disorder. Persons suffering from this disorder, called [[Trimethylaminuria]], may suffer from a strong fishy or otherwise unpleasant body odor due to the body's release of odorous trimethylamine. A body odor will occur even on a normal diet - ''i.e.'', one that is not particularly high in choline. Persons with Trimethylaminuria are advised to restrict the intake of foods high in choline; this may help to reduce the sufferer's body odor.
==Sources==
==Sources==
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The foods richest in [[lecithin|phosphatidylcholine]] -- the major delivery form of choline -- are beef liver, egg yolks and [[soybean|soy]]. Beefliver, iceberg lettuce,peanutbutter,peanuts,sunflowerseeds, andcauliflower are somefoodsthatcontainfreecholine. In 2004 USDAhas released its first database of the choline content in common foods[http://www.nal.usda.gov/fnic/foodcomp/Data/Choline/Choline.html].
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The foods richest in [[phosphatidylcholine]] — the major delivery form of choline — are [[egg yolks]], [[soybean|soy]] and cooked [[beef]], [[chicken]], [[veal]] and [[turkey]] livers. Manyfoods contain trace amounts of free choline, even iceberg [[lettuce]].Towhatextentthesetraceforms are usableby[[absorption(digestive)|humandigestion]]is still debated. In [[2004]],the[[United States Department of Agriculture|USDA]] released its first database of the choline content in common foods.<ref>"[http://www.nal.usda.gov/fnic/foodcomp/Data/Choline/Choline.html USDA Database for the Choline Content of Common Foods - 2004]", ''USDA Nutrient Data Laboratory''</ref>
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The bestabsorbed choline supplement is lecithin from soy or egg yolk.WhenscientistsatCentralSoyaCorporationaddedlecithin/cholinesupplementtoratchowduringthefirsttrimesterofpregnancythesupplementedoffspringhadgeniusmemorycomparedtoratswhodidnotreceivethecholine supplement. Theeffectwaslifelong. Theeffectwastracedtoenhancement of a partofthebraincalledthehippocampus.
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The mostoften available choline [[dietary supplement]] is [[lecithin]], derived from soy or egg yolks,oftenusedasa[[foodadditive]].[[Phosphatidylcholine]]isalsoavailableasasupplement,inpillorpowderform.SupplementaryCholineisalsoavailableasCholineChloride,whichcomesasaliquidduetoitshydrophilicproperties. Cholinechlorideissometimespreferredas a supplement because[[phosphatidylcholine]]canhavegastrointestinalsideeffects.
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Itis well established that supplements of methyl group transfer vitamins B6, B12, folic acid reduce the blood titer of homocystine and prevent heart disease. Choline is a necessary source of methyl groups for methyl group transfer. Supplements of lecithin/choline by Central Soya scientists reduced heart disease in laboratory studies. The reduction in heart disease with lecithin supplements may however relate more to the cholesterol carrying capacity of lecithin than to the methyl group transfer role of choline.
*[http://www.abc.net.au/rn/talks/8.30/helthrpt/stories/s119524.htm An interview about Choline with Steven Zeisel, Editor-in-Chief of the Journal of Nutritional Biochemistry]
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*[[Succinylcholine]]
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*[http://www.nal.usda.gov/fnic/foodcomp/Data/Choline/Choline.html USDA Database for the Choline Content of Common Foods]
When choline is metabolized by the body, it may form trimethylamine, a compound with a fishy odor. Hence, when large amounts of choline are taken the person may suffer from a fishy body odor.
Choline as a supplement
It is well established that supplements of methyl group transfer vitamins B6, B12, folic acid reduce the bloodtiter of homocysteine and prevent heart disease. Choline is a necessary source of methyl groups for methyl group transfer. Supplements of lecithin/choline by Central Soya scientists reduced heart disease in laboratory studies. The reduction in heart disease with lecithin supplements may however relate more to the cholesterol carrying capacity of lecithin than to the methyl group transfer role of choline.[specify]
Choline supplements are often taken as a form of 'smart drug' or nootropic, due to the role that the neurotransmitter acetylcholine plays in various cognition systems within the brain. Choline is a chemical precursor or "building block" needed to produce the neurotransmitter acetylcholine, and research suggests that memory, intelligence and mood are mediated at least in part by acetylcholine metabolism in the brain. The compound's quaternary amine renders it lipid insoluble and theoretically unable to cross the blood-brain barrier. However, despite choline's lipid insolubility, a choline transporter exists that allows transport across the blood-brain barrier. The efficacy of these supplements in enhancing cognitive abilities is a topic of continuing debate.
Some people who practice lucid dreaming use Galantamine with Choline to increase their odds of having a Lucid dream.
Due to its role in lipid metabolism, choline has also found its way into nutritional supplements which claim to reduce body fat; but there is little or no evidence to prove that it has any effect on reducing excess body fat or that taking high amounts of choline will increase the rate at which fat is metabolised.
Choline is a precurser to trimethylamine, which some persons are not able to break down due to a genetic disorder. Persons suffering from this disorder, called Trimethylaminuria, may suffer from a strong fishy or otherwise unpleasant body odor due to the body's release of odorous trimethylamine. A body odor will occur even on a normal diet - i.e., one that is not particularly high in choline. Persons with Trimethylaminuria are advised to restrict the intake of foods high in choline; this may help to reduce the sufferer's body odor.
Sources
The foods richest in phosphatidylcholine — the major delivery form of choline — are egg yolks, soy and cooked beef, chicken, veal and turkey livers. Many foods contain trace amounts of free choline, even iceberg lettuce. To what extent these trace forms are usable by human digestion is still debated. In 2004, the USDA released its first database of the choline content in common foods.[5]
The most often available choline dietary supplement is lecithin, derived from soy or egg yolks, often used as a food additive. Phosphatidylcholine is also available as a supplement, in pill or powder form. Supplementary Choline is also available as Choline Chloride, which comes as a liquid due to its hydrophilic properties. Choline chloride is sometimes preferred as a supplement because phosphatidylcholine can have gastrointestinal side effects.
↑"Choline" (An interview with Steven Zeisel, Editor-in-Chief of the Journal of Nutritional Biochemistry), Radio National Health Report with Norman Swan, Monday 17 April 2000
