If it's essential role in health is any indication, alpha-lipoic acid may very well join the ranks of vitamins C and E as part of your first-line of defense against free radicals. Discovered in 1951, it serves as a coenzyme in the Krebs cycle and in the production of cellular energy. In the late 1980s, researchers realized that alpha-lipoic acid had been overlooked as a powerful antioxidant.
The body routinely converts some alpha-lipoic acid to dihydrolipoic acid, which appears to be an even more powerful antioxidant. Both forms of lipoic acid quench peroxynitrite radicals, an especially dangerous type consisting of both oxygen and nitrogen, according to a recent paper in FEBS Letters (Whiteman M, et al., FEBS Letters, 1996; 379:74-6). Peroxynitrite radicals play a role in the development of atherosclerosis, lung disease, chronic inflammation, and neurological disorders.
Alpha-lipoic acid also plays an important role in the synergism of antioxidants, what Packer prefers to call the body's "antioxidant network." It directly recycles and extends the metabolic lifespans of vitamin C, glutathione, and coenzyme Q10, and it indirectly renews vitamin E.
