L-α-Glycerophosphorylcholine (alpha-GPC, choline alfoscerate, ''sn''-glycero-3-phosphocholine) is a natural
choline
Choline is a cation with the chemical formula . Choline forms various Salt (chemistry), salts, such as choline chloride and choline bitartrate. An essential nutrient for animals, it is a structural component of phospholipids and cell membrane ...
compound found in the brain. It is also a
parasympathomimetic
A parasympathomimetic drug, sometimes called a cholinomimetic drug or cholinergic receptor stimulating agent, is a substance that stimulates the parasympathetic nervous system (PSNS). These chemicals are also called cholinergic drugs becaus ...
acetylcholine
Acetylcholine (ACh) is an organic compound that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Par ...
precursor
which has been investigated for its potential for the treatment of
Alzheimer's disease
Alzheimer's disease (AD) is a neurodegenerative disease and the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems wit ...
[
] and other
dementia
Dementia is a syndrome associated with many neurodegenerative diseases, characterized by a general decline in cognitive abilities that affects a person's ability to perform activities of daily living, everyday activities. This typically invo ...
s.
Alpha-GPC rapidly delivers
choline
Choline is a cation with the chemical formula . Choline forms various Salt (chemistry), salts, such as choline chloride and choline bitartrate. An essential nutrient for animals, it is a structural component of phospholipids and cell membrane ...
to the brain across the
blood–brain barrier
The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system ...
and is a biosynthetic precursor of
acetylcholine
Acetylcholine (ACh) is an organic compound that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Par ...
.
It is a non-prescription drug in most countries. The
FDA
The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...
determined that intake of no more than 196.2 mg/person/day is considered
generally recognized as safe
Generally recognized as safe (GRAS) is a United States Food and Drug Administration (FDA) designation that a chemical or substance added to food is considered safe by experts under the conditions of its intended use. An ingredient with a GRAS d ...
(GRAS).
Production
Industrially, alpha-GPC is produced by the chemical or enzymatic deacylation of
phosphatidylcholine
Phosphatidylcholines (PC) are a class of phospholipids that incorporate choline as a headgroup.
They are a major component of biological membranes and can easily be obtained from a variety of readily available sources, such as egg yolk or soyb ...
enriched soya
phospholipids
Phospholipids are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule). Marine phospholipids typi ...
followed by
chromatographic purification. Alpha-GPC may also be derived in small amounts from highly purified soy
lecithin
Lecithin ( ; from the Ancient Greek "yolk") is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues which are amphiphilic – they attract both water and fatty substances (and so ar ...
as well as from purified sunflower lecithin.
Safety
A
retrospective cohort study
A retrospective cohort study, also called a historic cohort study, is a longitudinal cohort study used in medical and psychological research. A cohort of individuals that share a common exposure factor is compared with another group of equivale ...
involving 12 million participants in
South Korea
South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...
found that α-GPC users had a higher risk of stroke ( + 46 % ). The authors suggested that one possible explanation is that
dysbiosis
Dysbiosis (also called dysbacteriosis) is characterized by a disruption to the microbiome resulting in an imbalance in the microbiota, changes in their functional composition and metabolic activities, or a shift in their local distribution. For e ...
may lead to α-GPC being metabolized into
trimethylamine
Trimethylamine (TMA) is an organic compound with the formula N(CH3)3. It is a trimethylated derivative of ammonia. TMA is widely used in industry. At higher concentrations it has an ammonia-like odor, and can cause necrosis of mucous membranes ...
(TMA) in the gastrointestinal tract, and then to
trimethylamine N-oxide
Trimethylamine ''N''-oxide (TMAO) is an organic compound with the formula . It is in the class of amine oxides. Although the anhydrous compound is known, trimethylamine ''N''-oxide is usually encountered as the dihydrate. Both the anhydrous and ...
(TMAO) in the liver, which has implications for cardiovascular health. However, they also noted that the study could be influenced by
confounding
In causal inference, a confounder is a variable that influences both the dependent variable and independent variable, causing a spurious association. Confounding is a causal concept, and as such, cannot be described in terms of correlatio ...
variables, as α-GPC is often prescribed to individuals with preexisting health risks.
A later
systematic review
A systematic review is a scholarly synthesis of the evidence on a clearly presented topic using critical methods to identify, define and assess research on the topic. A systematic review extracts and interprets data from published studies on ...
and
meta-analysis
Meta-analysis is a method of synthesis of quantitative data from multiple independent studies addressing a common research question. An important part of this method involves computing a combined effect size across all of the studies. As such, th ...
criticized the statistical analysis of the South Korean cohort study, describing it as questionable and imprecise. The review concluded that α-GPC has a favorable safety and tolerability profile and is effective in improving cognitive function and daily living in patients with
dementia
Dementia is a syndrome associated with many neurodegenerative diseases, characterized by a general decline in cognitive abilities that affects a person's ability to perform activities of daily living, everyday activities. This typically invo ...
disorders of neurological origin, adult-onset
vascular dementia
Vascular dementia is dementia caused by a series of strokes. Restricted blood flow due to strokes reduces oxygen and glucose delivery to the brain, causing cell injury and neurological deficits in the affected region. Subtypes of vascular dement ...
, and
Alzheimer’s disease
Alzheimer's disease (AD) is a neurodegenerative disease and the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems wit ...
.
References
External links
Alpha-GPC on PsychonautWiki
{{DEFAULTSORT:Alpha-Gpc
Cholinergics
Dietary supplements
Neurotransmitter precursors
Nutrition
Vitamins
Neuropharmacology
Glycerol esters