Although alpha lipoic acid is involved in cellular energy production, its chief role as a dietary supplement may be as a powerful antioxidant. The body appears to be able to manufacture enough alpha-lipoic acid for its metabolic functions (as a co-factor for a number of enzymes involved in converting fat and sugar to energy), but the excess levels provided by supplements allow alpha-lipoic acid to circulate in a "free" state. In this state, alpha-lipoic acid has functions as both a water- and fat-soluble antioxidant. This unique ability of alpha-lipoic acid to be active in water and lipid compartments of the body is important because most antioxidants, such as vitamins C and E, are effective in only one area or the other. For instance vitamin C is usually restricted to the interior compartment of cells and the watery portion of blood, while vitamin E embeds itself in the fatty portion of cell membranes. Adding to the potential importance of alpha-lipoic acid is its role in the production of glutathione, one of the chief antioxidants produced directly by the body.
In animal studies, alpha-lipoic acid supplementation has been shown to improve several indices of metabolic activity and lower the degree of oxidative stress. Alpha-lipoic acid supplementation reversed the declines in oxygen consumption and mitochondrial energy production that are commonly observed with aging. Activity levels were increased by approximately 3-fold in animals fed the supplement, suggesting that energy levels were enhanced. Levels of other antioxidants, such as glutathione and ascorbic acid, were also elevated in animals consuming alpha-lipoic acid, suggesting that the supplement may help protect and/or recycle these antioxidants and contribute to the overall capacity of the body to neutralize free radical damage
In conjunction with other antioxidants, such as vitamin E, alpha-lipoic acid may be doubly helpful in patients with diabetes. By promoting the production of energy from fat and sugar in the mitochondria, glucose removal from the bloodstream may be enhanced and insulin function improved. Indeed, alpha-lipoic acid has been shown to decrease insulin resistance and is prescribed frequently in Europe as a treatment for peripheral neuropathy (nerve damage) associated with diabetes. In the U.S., the American Diabetes Association has suggested that alpha-lipoic acid plus vitamin E may be helpful in combating some of the health complications associated with diabetes, including heart disease, vision problems, nerve damage and kidney disease. Alpha-lipoic acid has also been implicated in helping to protect the brain from damage following a stroke.
Although there have been relatively few studies conducted with alpha-lipoic acid in humans, it appears to be safe as a dietary supplement. Intakes of as much as 600 mg per day have been used for treatment of diabetic neuropathy, with no serious side effects.
If alpha-lipoic acid were just another antioxidant, then its value would be far less. After all, there are dozens of ingredients on the market that have powerful antioxidant functions. The unique qualities possessed by alpha-lipoic acid, functioning as both a water- and fat-soluble antioxidant make it an intriguing ingredient and a supplement worthy of serious consideration.
50 – 100 mg per day as a general antioxidant