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.
Where is it found?
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):
| Science Ratings | Health Concerns |
|---|---|
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 |
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Reliable
and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary studies
suggesting a health benefit or minimal health benefit. For an herb, supported by traditional use but minimal
or no scientific evidence. For a supplement, little scientific support and/or minimal health
benefit. |
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Who is likely to be deficient?
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.
How much is usually taken?
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.
Are there any side effects or interactions?
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.2
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. Zempleni J, Trusty TA, Mock DM. Lipoic acid reduces the activities of biotin-dependent carboxylases in rat liver. J Nutr 1997;127:1776–81.
