Vitamins, Minerals and Dietary Supplements
What is alpha-lipoic acid? Why do we need it?
Alpha-lipoic acid (ALA) is an antioxidant manufactured in the body. It is sometimes referred to as the ?universal? antioxidant because, unlike most antioxidants, it is soluble in both fat and water. In addition to being manufactured by the body, it can be found in some foods and supplements (see below).
ALA has several benefits, particularly for people with diabetes. It enhances glucose uptake in people with type-2 diabetes, inhibits the process of glybosylation (in which sugar molecules attach themselves to proteins), and can reduce nerve damage and pain caused by diabetes. Preliminary evidence suggests that ALA can improve visual function in people with glaucoma. Test-tube studies show that ALA can stop the HIV virus from replicating, but whether ALA supplements can help people infected with HIV remains unclear at this point.
How much alpha-lipoic acid should I take?
As of this writing, there is no clear evidence that any particular dose of ALA provides a benefit for any particular condition. In the abovementioned glaucoma study, researchers provided subjects with 150 mg of ALA per day. Other studies typically use between 750 and 800 mg per day. Some practitioners recommend 20-50 mg of alpha-lipoic acid daily to provide general antioxidant protection.
What are some good sources of alpha-lipoic acid? What forms are available?
Small amounts of alpha-lipoic acid are produced naturally by the body. Some red meats ? particularly liver ? are believed to be good sources of ALA; supplements are also available.
What can happen if I don't get enough alpha-lipoic acid? What can happen if I take too much? Are there any side-effects I should be aware of?
Because alpha-lipoic acid is produced naturally in the body, deficiencies are not known to occur in humans. However, for people who take large doses of ALA supplements, some side-effects may occur, including skin rash, and diabetics run the risk of suffering hypoglycemia. Long-term use of alpha-lipoic acid in animals has been shown to interfere with the actions of the vitamin biotin, but research on humans has yet to be conducted.
As always, make sure to consult with a licensed health care provider before you begin taking alpha-lipoic acid or any other herbal remedy or dietary supplement.
References
- Busse E, Zimmer G, Schorpohl B, et al. Influence of alpha-lipoic acid on intracellular glutathione in vitro and in vivo. Arzneimittelforschung 1992;42:829-31.
- Filina AA, Davydova NG, Endrikhovskii SN, et al. Lipoic acid as a means of metabolic therapy of open-angle glaucoma. Vestn Oftalmol 1995;111:6-8.
- Lykkesfeldt J, Hagen TM, Vinarsky V, et al. Age-associated decline in ascorbic acid concentration, recycling, and biosynthesis in rat hepatocytes - reversal with (R)-alpha-lipoic acid supplementation. FASEB J 1998;12:1183-9.
- Nichols TW Jr. Alpha-lipoic acid: biological effects and clinical implications. Altern Med Rev 1997;2:177-83.
- Packer L, Witt EH, Tritschler HJ. Alpha-lipoic acid as a biological antioxidant. Free Radic Biol Med 1995;19:227-50.
