Serine: benefits, dosage, contraindications

Serine is a non-essential amino acid, naturally present in the body and abundantly found in various protein-rich foods, such as meat, eggs, dairy products, soy, and peanuts. Synthesized in the body from glycine and 3-phosphoglycerate, a metabolic intermediate, it plays a key role in several biological processes. Historically, its importance was recognized because of its involvement in protein and lipid metabolism. More recently, its role as a precursor of essential molecules such as phosphatidylserine and sphingomyelin, components of cell membranes, has been highlighted. Serine exists in two active forms: L-serine and D-serine, which differ in their molecular orientation and their roles in the body. L-serine is the predominant form in the diet and human metabolism, where it contributes to many essential biological functions. D-serine is produced in small amounts from L-serine by an enzyme, and plays a key role in the central nervous system. These two forms, although similar, have distinct properties. L-serine is essential for the synthesis of nucleotides and nucleic acids, which are involved in cell division and DNA repair. Furthermore, it contributes to the production of essential neurotransmitters, such as serotonin, often called the "happiness hormone". The latter plays an important role in the regulation of mood, stress, and sleep, positioning L-serine as a potential agent in improving circadian rhythms and sleep quality. Finally, D-serine, its derived form, is particularly active in the central nervous system. It acts in concert with glutamate to stimulate certain brain receptors, called NMDA receptors, which are necessary for strengthening neuronal connections and for memory. These properties make it a promising avenue for the prevention and treatment of neurological disorders such as schizophrenia, cognitive disorders, and neurodegenerative diseases.