Everything about Choline totally explained
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Choline is an
organic compound, classified as a water-soluble
essential nutrient 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
National Academy of Sciences.
History
Choline was discovered by Andreas Strecker in
1864 and
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.).
Chemistry
Choline is a
quaternary saturated amine with the
chemical formula: (
CH3)
3N+CH2CH2OHX
−.
where X
− is a
counterion such as
chloride (see
choline chloride),
hydroxide or
tartrate.
Choline chloride, in mixture with
urea is used as a solvent (
DES ) and the
salicylate salt is used topically for pain relief of
aphthous ulcers.
Physiology
Choline and its
metabolites are needed for three main
physiological purposes: structural integrity and
signaling roles for cell membranes, cholinergic
neurotransmission (
acetylcholine synthesis), and as a major source for
methyl groups via its metabolite,
trimethylglycine (betaine) that participates in the
S-adenosylmethionine synthesis
pathways.
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
blood titer 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.
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 which might suggest it would be 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.
Lakhan & Vieira (2008) link choline deficiency to bipolar disorder and report efficacy in lecithin supplementation based on a double-blind, placebo controlled trial.
Some people who practice
lucid dreaming use
Galantamine with Choline to increase their odds of having a lucid dream. In most scientific circles, however, the use of Choline to increase the effects of dreaming is considered a modern myth.
The
Food and Drug Administration (FDA) requires that
infant formula be made from cow's
milk containing choline.
Due to its role in
lipid metabolism, choline has also found its way into nutritional supplements which claim to reduce
body fat; but there's 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.
Fish odor syndrome
Choline is a precursor 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 -
for example, one that isn't 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.
Choline hydroxide
Choline hydroxide is one of the class of
phase transfer catalysts which are used to carry the
hydroxide ion into organic systems. It is far and away the least costly phase transfer catalyst, and gets a lot of use in stripping photoresists in printed circuit board production. Choline hydroxide isn't completely stable and it spontaneously, slowly breaks down to release
trimethylamine. It is a strong base.
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.
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.
Additional images
Image:Choline_Molecule.png|Choline (C5H14NO+)
Image:Choline chloride.png|Choline chloride
Image:Choline hydroxide.png|Choline hydroxide
Image:Cholina.png|Synthesis
Further Information
Get more info on 'Choline'.
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