Arginine as a Fatburner: Recent Evidence

Last week Tan, et al. (Tan. 8 July 2010) published the results of a study on the effect of arginine supplementation on porcine adipose tissue and skeletal muscle. The results shed some light on the purported fatloss effects of an amino acid many of you may know exclusively as a nitric oxide (NO) precursor in various preworkout products. The scientists found that ...

"Arg supplementation up-regulates expression of lipogenic genes in skeletal muscle. In contrast, the Arg treatment down-regulates expression of lipogenic genes and increases expression of lipolytic genes in white adipose tissue. Such changes in expression of lipid-metabolic genes favor the storage of lipids in skeletalmuscle but the loss of fat from subcutaneous adipose tissue in growing-finishing pigs."

Also of interest is the marked increase in oleic acid concentration in skeletal muscle:

"Such a physiological effect of Arg is beneficial for humans, because oleic acid stimulates glucose uptake by skeletal muscle for oxidation, thereby potentially reducing the availability of circulating glucose for fatty acid synthesis in other tissues. Additionally, palmitoleate (C16:1n7) has recently been identified as a lipokine to enhance muscle insulin action and suppress hepatosteatosis in mice."

Bottom line, do not follow the supplement industry's advice to give up on your favorite arginine powered "1st generation"-preworkout product (e.g. NO Xplode, White Flood, Super Pump 250, VPX Shotgun). While its NO-boosting effects are indeed debatable, arginine could eventually help you to shed the last pounds of body fat that covers yours abs, thighs or whatever you consider your particular problem areas.

As a side note: Swine as omnivores provide a much better model for the human metabolism than rats or mice, so the authors' conclusion that the results of this study offer additional insight into human physiology, as well, appears justified.