Alpha Lipoic Acid

. . . .Promotes healthy nerve function by preventing oxidative damage*

Features & Benefits

• Water and lipid-soluble antioxidant*

• Promotes normal nerve function*

• Promotes healthy pancreatic function*

• Helps maintain healthy eyes*

Facts About Alpha Lipoic Acid

        Free Radicals: Alpha lipoic acid (ALA) is an antioxidant co-enzyme found in foods and the body.1  It acts both as a water- and fat-soluble antioxidant, and therefore benefiting different body tissues.*2  Part of how it accomplishes this task is by chelating metal ions, such as copper, that tend to promote oxidation.1  Lipoic acid also regenerates other antioxidants, including vitamins C and E 2,3 and coenzyme CoQ10.*4 It accomplishes this by donating electrons to replace those given up by other antioxidants during free-radical scavenging activity.2

        Nerves: Protection of neurons (nerve cells) appears to be a major role of lipoic acid.*  In humans, amounts of 400-800 mg of ALA daily have been shown to promote healthy nerve function.*5,6  The first study (known by its German initials DEKAN) involved 39 people given 800 mg lipoic acid orally and 34 people given placebo for four months.5 The people taking lipoic acid showed a significant improvement in heart rate variability, an objective measure of the autonomic nerves serving the heart. This improvement was significant compared to the control group. There were no notable changes in adverse symptoms between the two groups. Oral doses under 600 mg daily have not been effective for nerve health in several studies.6

     Eyes: Lipoic acid may also help maintain normal pressure of the fluid in the eye, according to one human study.*7 A group of 19 people given 150 mg of lipoic acid orally for one month were shown to have a significant improvement in visual function compared to a control group treated with placebo.7 A dose of 75 mg daily was not effective in this study. Oxidation within the lens of the eye may contribute to declining clarity of vision with age.  Lipoic acid has been shown to protect animal lenses from such damage.*8 Human studies have not yet been performed confirming this benefit.

        Glucose: Lipoic acid inhibits the enzyme aldose reductase.9  This enzyme produces sugars that can damage the lens and nerves, particularly in patients with diabetes mellitus.  The ability of lipoic acid to limit aldose reductase activity may prove to offer protection for good eye health.* Lipoic acid promotes normal insulin sensitivity and glucose metabolism in the body.*2,10  Actual insulin and glucose levels in the blood may not change while taking lipoic acid.

                Energy: Preliminary evidence suggests lipoic acid promotes energy formation in the body.*11 Lipoic acid is a necessary cofactor in the enzyme complex central to the function of the citric acid cycle.* This cycle starts the process of energy production; one study suggests that oral lipoic acid therapy could improve energy formation by improving function of the mitochondria.*11 Further studies are necessary to validate and determine the importance of this possible lipoic acid benefit.

Safety and Toxicity

                At a level of intake of 200-800 mg daily, no significant adverse effects have been reported.  Thiamin deficiency may be aggravated by lipoic acid, so anyone at risk of this condition (particularly alcoholics) should supplement the two nutrients together.  Diabetic patients should only take lipoic acid above 200 mg daily if under the supervision of a nutritionally-oriented practitioner to prevent possible episodes of hypoglycemia.*2 There is no information regarding safety in pregnancy or lactation.

Ingredient Highlights

Lipoic acid was first isolated from potatoes.  It is also found in other foods including animal products.  It is well absorbed when taken orally.

References

1. Ou P, Tritschler HJ, Wolff SP. Thioctic (lipoic) acid: A therapeutic metal-chelating antioxidant? Biochem Pharmacol 1995;50:123-6.

2. Nichols TW Jr. Alpha-lipoic acid: Biological effects and clinical implications. Alt Med Review 1997;2(3):177-82 [review].

3. Kagan VE, Serbinova EA, Forte T, et al. Recycling of vitamin E in human low density lipoproteins. J Lipid Res 1992;33:385-97.

4. Kagan V, Serbinova E, and Packer L. Antioxidant effects of ubiquinones in microsomes and mitochondria are mediated by tocopherol recycling. Biochem Biophys Res Comm 1990;169:851-7.

5. Ziegler D, Schatz H, Conrad F, et al. Effects of treatment with the antioxidant alpha-lipoic acid on cardiac autonomic neuropathy in NIDDM patients. Diabetes Care 1997;20:369-73.

6. Ziegler D, Gries FA. Alpha-lipoic acid in the treatment of diabetic peripheral and cardiac autonomic neuropathy. Diabetes 1997;46(suppl 2):S62-6 [review].

7. Filina AA, Davydova NG, Endrihovskii SN, et al. Lipoic acid as a  means of metabolic therapy of open-angle glaucoma. Vestnik  Oftalmol 1995;111:6-8 [in Russian].

8. Maitra I, Serbinova E, Tritschler H, Packer L. Alpha-lipoic acid prevents buthionine sulfoximine-induced cataract formation in  newborn rats. Free Rad Biol Med 1995;18:823-9.

9. Ou P, Nourooz-Zadeh J, Tritschler HJ, Wolff SP. Activation of aldose reductase in rat lens and metal-ion chelation by aldose reductase inhibitors and lipoic acid. Free Rad Res 1996;25:337-46.

10. Jacob S, Henriksen EJ, Schiemann AL, et al. Enhancement of glucose disposal in patients with type 2 diabetes by alpha-lipoic acid. Arzneim Forsch 1995;45:872-4.

11. Barbiroli B, et al. Lipoic (thioctic) acid increases brain energy availability and skeletal muscle performance as shown by in vivo 31P-MRS in a patient with mitochondrial cytopathy. J Neurol  1995;242:472-7.