Alpha-Ketoglutarate

What is alpha-ketoglutarate?

Alpha-ketoglutarate, often abbreviated as AKG or written as α-ketoglutarate, is a naturally occurring molecule in human metabolism. It is a key intermediate in the citric-acid cycle, also known as the Krebs cycle.

The citric-acid cycle takes place mainly in mitochondria and is central to cellular energy production.

Where does AKG occur?

AKG is produced by the body and is present in virtually every cell. Unlike many nutrients, it is not obtained in meaningful quantities directly from food. Its concentration changes according to metabolism, exercise, fasting and age.

What functions does AKG have?

• Cellular energy production
• Amino-acid metabolism
• Nitrogen transport
• Ammonia detoxification
• Collagen synthesis
• Epigenetic enzyme reactions
• Oxygen-sensing pathways

It connects carbohydrate, fat and protein metabolism and can be converted into the amino acid glutamate.

AKG and ammonia metabolism

AKG can bind nitrogen through transamination reactions. This contributes to the safe transport and processing of ammonia, a toxic by-product of amino-acid metabolism.

AKG and epigenetics

Several enzymes that regulate DNA and histone methylation require AKG as a cofactor. These include TET enzymes and Jumonji-domain demethylases.

This makes AKG relevant to cell differentiation, gene regulation and aging research.

AKG and aging

Animal studies have reported that AKG supplementation may influence lifespan, inflammation, bone health and frailty. One widely discussed mouse study found that calcium alpha-ketoglutarate extended healthy lifespan and reduced age-related decline.

These results are scientifically interesting but cannot be transferred directly to humans.

Calcium alpha-ketoglutarate

CaAKG is the calcium salt of alpha-ketoglutarate. It provides both AKG and calcium and is commonly used in supplements. The amount of elemental calcium depends on the exact compound and formulation.

Safety

AKG salts are generally considered well tolerated at moderate doses. Possible adverse effects include digestive discomfort.

People with kidney disease, disturbances of calcium metabolism, pregnancy or regular medication use should seek medical advice before supplementation.

Conclusion

Alpha-ketoglutarate is a central metabolic molecule involved in energy production, nitrogen metabolism and epigenetic regulation. Animal research has made it an important longevity candidate, but robust human evidence for anti-aging effects is still limited.