Glycine AKG a longevity supplement?
We recently wrote about a Japanese in-vitro study in which the amino acid glycine rejuvenated older cells. So apparently glycine along is suitable for inclusion in an anti-aging supplement. In 2014 biochemists at the University of California Los Angeles published a study in Nature which could lead you to speculate that glycine AKG might work even better.
AKG is an abbreviation for alpha-ketoglutarate [structural formula shown on the right]. Cells produce this substance when they convert amino acids into energy. The supplements industry sells amino acids that are attached to AKG in the hope that these work better than amino acids on their own.
In their Nature study, the researchers exposed nematodes, Caenorhabditis elegans, to AKG and observed that they lived longer as a result. Each line on the graph represents an individual, but identical experiment.
The optimal concentration was 4-10 millimoles, as the figure above shows.
AKG reduced the concentration of ATP in the nematodes.
When the researchers modified the nematodes genetically so that their cells produced less ATP [atp-2 RNAi], they saw that the nematodes lived longer as a result – and that AKG supplementation no longer had a life-extending effect.
AKG is released during caloric restriction, the researchers write, so supplementation probably imitates the effects of caloric restriction.
"Longevity molecules that delay ageing and extend lifespan have profound implications and have long been a dream of humanity", the researchers wrote. "Endogenous metabolites such as AKG that can alter Caenorhabditis elegans lifespan suggest that an internal mechanism may exist that is accessible to a myriad of regulations and interventions."
Wild speculation on our part
It may just be the case that AKG and glycine reinforce each other's life-extending effects. They are both linked to energy processes in the cell, but not in the same way. In addition, AKG inhibits the breakdown of glycine in the liver, so AKG boosts the bioavailability of glycine. [Arch Biochem Biophys. 1986 Sep;249(2):263-72.]
Nature. 2014 Jun 19;510(7505):397-401.
Glycine rejuvenates old cells 24.08.2015