ARGININE ALPHA-KETOGLUTARATE (AAKG):
Arginine alpha-ketoglutarate (AAKG) is a salt formed by combining two molecules of the amino acid Arginine and one molecule of alpha-ketoglutarate. Because AKG seems to be involved in amino acid synthesis and protein availability, many athletes supplement with AKG as a way to increase muscle mass and strength – although the evidence for its effectiveness is this regard is quite limited.
Increases muscle size and strength
Reduces body fat
Stimulates the immune system
AAKG has been used to treat patients suffering from burns, surgery, malnutrition and other trauma. Although the precise mechanism is unknown, AKG treatment decreases muscle protein catabolism (breakdown) and/or increases protein synthesis, in addition to promoting wound healing. AKG may promote the secretion of anabolic hormones such as insulin and growth hormone and increase amino acid metabolism (glutamine & arginine), which may help explain some of the clinical findings.
Arginine ia a precursor of nitric oxide and polyamines, respectively -metabolites which participate in a number of metabolic functions. AKG supplements have been shown to promote growth hormone and insulin secretion with anabolic effects in postoperative patients. Their intermediary metabolites (glutamine & proline) may also have beneficial effects in promoting recovery from trauma. In animal studies, AKG supplementation increases levels of arginine and glutamine in skeletal muscles and stimulates immune system function compared to animals not receiving AKG. The immunomodulatory properties found with AKG suggest that it may enhance host-defense mechanisms, particularly during injury and acute stress
AAKG supplements (15 grams per day for 5 months) have been shown to improve growth rates in small children. The AAKG supplements resulted in elevated concentrations of anabolic (growth) hormones and amino acid metabolites, including insulin-like growth factor 1 (IGF1), glutamine and glutamate. In another study of healthy men, AAKG given at 10 grams per day resulted in a 20-30% elevation in insulin (another anabolic hormone), which were not observed with supplementation of either Arginine or alpha-ketoglutarate alone.
A test tube study found that AAKG induces a significant increase in growth of human fibroblasts – cells with similarities to muscle fiber cells. This effect was dose-dependent, meaning that a more pronounced growth effect was noted with increasing levels of AAKG (but not with increasing levels of Arginine or alpha-ketoglutarate alone).
In one study, the anti-catabolic effects of AAKG were investigated in 14 multiple trauma patients who were highly catabolic and hyper-metabolic. One group of subjects received 20 grams of AAKG per day and showed a significant increase in protein turnover as well as a an increase in blood levels of insulin, growth hormone, and free amino acids (glutamine, proline and Arginine) compared to subjects not receiving AAKG supplements.