SAMe (S-adenosyl-methionine) is an amino acid derivative normally synthesized in the body. SAMe is used by the body in three important pathways:
- Methylation (contributing methyl groups to activate certain molecules)47,48
- The synthesis of polyamines (for cell growth, gene expression, neuronal regeneration, etc.)49-51
- Trans-sulfuration (synthesis of cysteine, glutathione, and other sulfate chemicals)52-54
SAMe occurs naturally in the body. It is concentrated in the liver and brain and is a major methyl donor in the synthesis of hormones, nucleic acids, proteins, and phospholipids, catecholamines, and other neurotransmitters, such as dopamine and serotonin. SAMe is required for the synthesis of norepinephrine, dopamine, and serotonin, and also plays a role in other intracellular metabolic pathways.55,56 SAMe facilitates glutathione57,58 usage and maintains acetylcholine levels,59,60 which help enhance or maintain cognitive function and attenuate or prevent aggression of aging and neurodegeneration.
SAMe levels may become depleted from sickness and age. Supplementation with the co-factors — folate, trimethylglycine (TMG or betaine), vitamins B6 and B12, together with SAMe — appears to be an effective method to overcome this deficiency. There is evidence that SAMe helps to synthesize phosphatidylcholine, which keeps cell membranes fluid, and is used in the brain to make the neurotransmitter acetylcholine.47,50,61
In 2002, an agency of the U.S. Department of Health and Human Services conducted a meticulous evaluation of SAMe. Its findings show the efficacy of SAMe in helping to maintain stable mood and joint function without any side effects.62 Since aging people often suffer joint discomfort and immobilization, SAMe addresses multiple problems people face as they grow older.49,60,63-66 In addition, SAMe has multiple mechanisms of action that are used throughout the body, especially in the liver, which help maintain liver health. SAMe facilitates healthy methylation enzymatic processes and boosts hepatic levels of the critical antioxidant glutathione.57,58,67 When liver function is compromised, glutathione is depleted, which leads to free radical damage.