A nutrient that is used by the vast majority of the cells in the body to synthesize structural membranes.
It's especially useful to our brains in synthesis and release process of the neurotransmitter acetylcholine by neurons.
Choline, a water-soluble nutrient, usually grouped with B vitamins is essentially one step removed from the real nootropic, Acetylcholine, for which it is a chemical precursor. Choline itself cannot travel across the blood-brain barrier to become Acetylcholine, bitrate Choline is somewhat more effective in crossing it and Alpha-GPC freely moves from the bloodstream into the brain.
In a population study done in Hordaland, Norway of 46-74 year olds choline blood levels were found to be inversely correlated with anxiety symptoms. Choline is used as treatment for bipolar disorder, alcoholism and Alzheimer's disease. Choline is very important during pregnancy, rat experiments support the theory that healthy levels of Choline during pregnancy are essential long term memory capacity of the baby.
Rat testing has also demonstrated that alcohol lowers Choline levels, obviously this isn't good for your long term brain health so it's probably a good idea to supplement a Choline nootropic if you drink socially.
It's a good idea to supplement Choline if you are taking Piracetam or other racetam nootropics which increases the rate at which your brain uses Acetylcholine. Otherwise the racetams can cause headaches. In nature we find Choline in high amounts in raw beef liver, wheat germ, cod fish and milk. It can also be supplement in pill form.
Phosphatidylcholine is a substance synthesized by Choline that some researchers believe may affect the aging process on the brain including fighting dementia.