Alpha Lipoic Acid
Also indexed as: ALA, Lipoic Acid, Thioctic Acid
Alpha lipoic acid (ALA) is a vitamin-like antioxidant, sometimes referred to as the “universal antioxidant” because it is soluble in both fat and water.1 ALA is manufactured in the body and is found in some foods, particularly liver and yeast.
ALA is capable of regenerating several other antioxidants back to their active states, including vitamin C,2 vitamin E,3 glutathione,4 and coenzyme Q10.5
ALA has several potential benefits for people with diabetes. It enhances glucose uptake in type 2 (adult onset or non-insulin-dependent) diabetes, inhibits glycosylation (the abnormal attachment of sugar to protein), and has been used to improve diabetic nerve damage and reduce pain associated with that nerve damage.6 Most studies have used intravenous alpha lipoic acid, but oral supplementation has nonetheless proved partially helpful in treating at least one form of diabetic neuropathy, using 800 mg per day.7
Preliminary evidence indicates that 150 mg of alpha lipoic acid, taken daily for one month, improves visual function in people with glaucoma.8
ALA has been shown to inhibit the replication of the HIV virus in the test tube; however, it is not known whether supplementing with ALA would benefit HIV-infected people.9
Intravenous administration of ALA has significantly increased the survival rate of people who have eaten poisonous mushrooms.10 Such a treatment should be prescribed by a doctor and should not be attempted on one’s own.
The body makes small amounts of alpha lipoic acid. There is only limited knowledge about the food sources of this nutrient. However, foods that contain mitochondria (a specialized component of cells), such as red meats, are believed to provide the most alpha lipoic acid. Supplements are also available.
Alpha lipoic acid has been used in connection with the following conditions (refer to the individual health concern for complete information):
Although alpha lipoic acid was thought to be a vitamin when it was first discovered, subsequent research determined that it is created in the human body—and thus is not an essential nutrient. For this reason, deficiencies of alpha lipoic acid are not known to occur in humans.
The amount of alpha lipoic acid used in research to improve diabetic neuropathies is 800 mg per day and 150 mg per day for glaucoma. However, much lower amounts, such as 20–50 mg per day, are recommended by some doctors for general antioxidant protection, although there is no clear evidence that such general use has any benefit.
Side effects with alpha lipoic acid are rare but can include skin rash and the potential of hypoglycemia in diabetic patients. People who may be deficient in vitamin B1 (such as alcoholics) should take vitamin B1 along with alpha lipoic acid supplements. Chronic administration of alpha lipoic acid in animals has interfered with the actions of the vitamin, biotin. Whether this has significance for humans remains unknown.11
At the time of writing, there were no well-known drug interactions with alpha lipoic acid.
1. Kagan V, Khan S, Swanson C, et al. Antioxidant action of thioctic acid and dihydrolipoic acid. Free Radic Biol Med 1990;9S:15.
2. Lykkesfeldt J, Hagen TM, Vinarsky V, Ames BN. 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.
3. Scholich H, Murphy ME, Sies H. Antioxidant activity of dihydrolipoate against microsomal lipid peroxidation and its dependence on alpha-tocopherol. Biochem Biophys Acta 1989;1001:256-61.
4. Busse E, Zimmer G, Schorpohl B, et al. Influence of alpha-lipoic acid on intracellular glutathione in vitro and in vivo. Arzneimittelforschung1992;42:829-31.
5. Kagan V, Serbinova E, Packer L. Antioxidant effects of ubiquinones in microsomes and mitochondria are mediated by tocopherol recycling. Biochem Biophys Res Commun 1990;169:851-7.
6. Packer L, Witt EH, Tritschler HJ. Alpha-lipoic acid as a biological antioxidant. Free Radic Biol Med 1995;19:227-50 [review].
7. Ziegler D, Ulrich H, Schatz H, et al. Effects of treatment with the antioxidant alpha-lipoic acid on cardiac autonomic neuropathy in NIDDM patients. Diabetes Care 1997;20:369-73.
8. 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.
9. Baur A, Harrer T, Peukert M, et al. Alpha-lipoic acid is an effective inhibitor of human immuno-deficiency virus (HIV-1) replication. Klin Wochenschr 1991;69:722-4.
10. Nichols TW Jr. Alpha-lipoic acid: biological effects and clinical implications. Altern Med Rev 1997;2:177-83 [review].
11. Zempleni J, Trusty TA, Mock DM. Lipoic acid reduces the activities of biotin-dependent carboxylases in rat liver. J Nutr 1997;127:1776–81.