Facts on Lipoic Acid

Lipoic acid, better known as alpha-lipoic acid, or ALA, is a sulfur-containing molecule that is classified as an antioxidant. Antioxidants are compounds that are capable of removing harmful free radicals, which are byproducts of metabolism or toxic exposures, from living tissues. According to Dr. Elson Haas, author of "Staying Healthy with Nutrition," ALA is somewhat unique in its ability to scavenge free radicals from both fat-soluble and water-soluble environments. Because your body contains both aqueous and lipid components, ALA is a particularly beneficial antioxidant.

Mirror-Image Molecule

ALA exists in two molecular forms, which are mirror images of each other. One form, R-ALA, occurs in nature while the other form, S-ALA, is manufactured in the laboratory. R-ALA is synthesized within your cells and is essential for normal metabolism. S-ALA cannot be used by living cells. Most ALA supplements contain both R- and S-forms -- probably to provide a cheaper, diluted version -- but pure R-ALA is commercially available.

Lipoic Acid Functions

While ALA is an effective antioxidant in its own right, it also helps to regenerate other antioxidants that are consumed by metabolic processes within your body. For example, vitamin C, a potent antioxidant vitamin, is oxidized to dehydroascorbic acid when it removes a free radical from your tissues. ALA converts this oxidized molecule back into the active form of vitamin C. In a similar fashion, ALA "repairs" other inactivated antioxidants or enhances their synthesis. Glutathione, a key cellular antioxidant that cannot be absorbed from supplements, is preserved when ALA is also present.

Anti-Aging

Some scientists have proposed that ALA might prove useful in slowing the effects of aging, including the cognitive decline associated with Alzheimer's disease. A 2007 review in "Journal of Neural Transmission" suggested that high doses of ALA slowed Alzheimer's progression to a greater degree than standard medical therapy. Similarly, ALA has been touted as a means to retard the degeneration of collagen and other proteins that occurs with aging, and a study in "Investigative Ophthalmology and Visual Science" demonstrated that ALA reduced oxidative damage in retinal cells, perhaps indicating a use for ALA in treating age-related eye diseases. However, ALA has not been scientifically proven to slow the aging process.

Diabetes

Decreased insulin sensitivity and oxidative injury to small vessels and nerves are hallmarks of diabetes. ALA has been shown to reduce oxidative stress in diabetics, and a 2006 study published in the journal "Hormones" revealed that high-dose ALA supplementation improved insulin sensitivity and the rate of glucose metabolism in type 2 diabetics. ALA is not intended to treat or cure diabetes. If you are diabetic and would like to try ALA, consult your physician.

Other Conditions

ALA has been studied for its potential benefits in other conditions, including erectile dysfunction, glaucoma, multiple sclerosis, thyroid disorders and obesity, to name a few. Lipoic acid is a common ingredient in cosmetics, presumably because it reduces the impact of environmental toxins and solar radiation on the skin. While ALA is known to be an effective antioxidant with beneficial physiologic effects, it is not approved in the U.S. for treating or preventing any disease. If you feel ALA would be useful to you, check with your doctor.