Reprinted with the kind permission of Life Extension.
March 15 2019. A report published on March 7, 2019 in the journal PLoS Genetics documents a life-extending benefit for the amino acids glycine and serine in the roundworm Caenorhabditis elegans (C. elegans).
“To date the role of glycine has not been systematically defined in animal models of longevity,” write Yasmine J. Liu and her colleagues at the University of Amsterdam. “In this study, we build upon our previous observations that suggest glycine accumulation in aging animals may play a unique and as-of-yet unexplored role in the regulation of eukaryote lifespan.”
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While concentrations of most amino acids decline during aging in C. elegans, the exception is glycine, which continues to accumulate. It was discovered that the expression of genes involved in glycine degradation was reduced during the worms’ late adulthood while gene expression involved in glycine synthesis remained unchanged during aging. In long-lived C. elegans strains, glycine levels were significantly higher during aging in comparison to levels measured during larval stages.
When the worms were given low amounts of glycine, an increase in median lifespan of 7.7% to 19.2% occurred in comparison with untreated controls. A similar effect was observed when C. elegans were supplemented throughout their lives or during adulthood with serine, an amino acid that is a precursor of glycine. “Taken together, we suggest a model whereby both glycine and serine supplementation stimulate longevity in a methionine cycle-dependent fashion and through common signaling pathways,” the authors write.
Although some glycine is made in the body from the amino acid serine, evidence exists that the amount synthesized combined with the small quantity provided by the diet may be insufficient for the body’s metabolic needs. It has been suggested that glycine should be classified as a semi-essential amino acid and that supplementation may be of benefit.