Alpha-lipoic acid or thioctic acid is an antioxidant used to help fight medical conditions such as nerve problems you might experience from diabetes, damaged livers, degenerative diseases and even aging. It is considered a super-antioxidant, and in the oxidized or reduced state, it is known as R-alpha-lipoic acid. The R- form is fat- and water-soluble and can be transported across cell membranes, including in the brain. Researchers from the Linus Pauling Institute and University of Maryland indicate that the pure form or R- form of alpha-lipoic acid is more effective than the synthetic form.
Alpha-lipoic acid occurs in three forms: R-lipoic acid (RLA), a naturally occurring compound produced in your body, S-lipoic acid, a byproduct from chemical synthesis, and alpha-lipoic acid, a 50/50 mix of R and S. Alpha-lipoic acid is synthetic and is the original form used as vitamins and supplements, and in most research.
Alpha-lipoic acid was discovered in the 1930s and was considered a vitamin. By 1988, research revealed that alpha-lipoic acid is the only antioxidant known to work in both fat- and water-soluble tissues, and in the late 1990s, it was classified as a supplement.
According to LE Magazine, only the R portion of alpha-lipoic acid is biologically active and you don’t need as much to get the antioxidant and neuroprotective benefits. The Linus Pauling Institute found that “taking R-lipoic acid was more effective than racemic alpha-lipoic acid and S-alpha-lipoic acid in preventing cataracts in rats.”
The major functions of alpha-lipoic acid are to act as a powerful antioxidant, destroying free radicals in your body, and to regenerate other antioxidants, such as vitamins C and E. Alpha-lipoic acid also increases the formation of glutatione (GHS), another important antioxidant that usually decreases with age and is vital to your white blood cells and your liver, where it assists with detoxification and elimination of free radicals.
Sources of alpha-linoic acid include supplements, foods such as broccoli, spinach, tomatoes, peas, brussels sprouts, rice bran, egg yolk, beef liver, beef heart and beef kidney.
Large amounts of alpha-lipoic acid should be taken under a physician's direction. If you choose to take an alpha-lipoic acid supplement, it is sold in the synthetic form or the R-alpha-lipoic. Check your health stores. For generally healthy people, the Linus Pauling Institute recommends a daily dose of 200mg to 400mg per day of racemic lipoic acid. If you are taking the R-form, you may only need half the dosage.