Lipoic Acid (Thioctic Acid)

James Meschino DC, MS, ROHP

General Features

Lipoic Acid is a sulfur-containing, vitamin like substance.  Although the body manufactures Lipoic Acid, under certain circumstances, supplementation has been shown to be beneficial.

Lipoic Acid functions as a co-enzyme (with vitamin B₁ and niacin) in the conversion of pyruvate to acetyl co-enzyme A, thus it is essential for aerobic energy metabolism.¹

Lipoic Acid is also a water soluble and fat soluble antioxidant.²  With coenzyme Q₁₀ and vitamin E, it appears to protect mitochondrial DNA from the damaging effects of oxygen-free radicals; providing a potential anti-aging effect in preserving mitochondrial DNA structure and function.³

Supplementation Studies

1. Diabetic Neuropathy

In Germany Lipoic Acid is approved as a drug for the treatment of diabetic neuropathy.  Its therapeutic effects appear to be mediated through its antioxidant effects.  However, it has also been shown to improve blood glucose metabolism, reduce glycosylation of amino acids (i.e. hemoglobin glycosylation), improve blood flow to peripheral nerves and stimulate regeneration of nerve fibers in diabetic subjects.  Lipoic Acid enhances insulin sensitivity in diabetics, which explains its beneficial effects on blood glucose regulation and reduced blood amino acid glycosylation.

For diabetic neuropathy studies reveal that combining 600 mg of Lipoic Acid daily, with 100 mcg of selenium, or 1,200 I.U. of vitamin E, produced significant results over the placebo.^4-9

2. AIDS

Lipoic Acid supplementation in AIDS patients has been shown to increase plasma ascorbic acid, glutathione, and T-helper lymphocytes and T-helper/suppressor cell ratio in a significant number of patients.  All of these factors are important biomarkers in AIDS progression, suggesting that Lipoic Acid supplementation may help slow the progression of HIV and AIDS.  The daily dosage was 1,500 mg, three times daily.

Studies indicate that Lipoic Acid inhibits HIV replication by reducing the activity of reverse transcriptase (the enzyme responsible for manufacturing the virus from the DNA of lymphocytes) and inhibits the activation in HIV that leads to viral replication.^10,11,12

3. Other Applications

Lipoic Acid supplementation may be considered in liver cirrhosis and other liver damage, heart disease, cataracts, heavy metal toxicity and support for detoxification and antioxidant functions.

Dosage

1. Diabetic Neuropathy: 300-600 mg daily^1,3
2. AIDS (HIV): 1,500 mg three times daily
3. General Support: 20 – 50 mg daily

Toxicity and Contraindications

Lipoic Acid is a very safe supplement with no significant adverse effects reported in over three decades of use in diabetics.  Animal studies demonstrate low toxicity.

Drug-Nutrient Interactions

As Lipoic Acid supplementation increases insulin sensitivity, insulin-dependent diabetics will need to adjust their insulin dosage with Lipoic Acid supplementation.  Therefore, these patients should not use Lipoic Acid supplementation without consulting their physician or diabetic specialist.

In non-insulin dependent diabetics, the dosage of oral hypoglycemic drugs may also need to be adjusted with Lipoic Acid supplementation.¹

1. Murray M. Encyclopedia of Nutritional Supplements. Rocklin, CA: Prima Publishing; 1996.  343-6.
2. Kagan VE, Shvedova A, Serbinova E, Khan S, Swanson C, Powell R, et al. Dihydrolipoic acid-A universal antioxidant both in the membrane and in the aqueous phase.  Reduction of peroxyl, ascorbyl and chromanoxyl radicals.  Biochem Pharmacol 1992;44:1637-49.
3. Barbiroli B, Medori R, Tritschler HJ, Klopstock T, Seibel P, Reichmann H, 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.
4. Packer L. Antioxidant properties of lipoic acid and its therapeutic effects in prevention of diabetes complications and cataracts.  Annals NY Acad Sci 1994;738:257-64.
5. Kahler W, Kuklinski B, Ruhlmann C, Plotz C. Diabetes mellitus: a free radical-associated disease.  Results of adjuvant antioxidant supplementation.  Z Gesamte Inn Med 1993;48(5):223-32.
6. Nagamatsu M, Nickander KK, Schmelzer JD. Lipoic acid improves nerve blood flow, reduces oxidative stress, and improves distal nerve conduction in experimental diabetic neuropathy.  Diabetic Care 1995;18:1160-7.
7. Jacob S, Henriksen EJ, Schiemann AL, Simon I, Clancy DE, Tritschler HJ, et al. Enhancement of glucose disposal in patients with type 2 diabetes by alpha-lipoic acid.  Arzneim Forsch 1995;45(8):872-4.
8. Kawabata T, Packer L. Alpha-lipoate can protect against glycation of serum albumin, but not low density lipoprotein. Biochem Biophys Res Comm 1994;203,99-104.
9. Suzuki YJ, Tsuchiya M, Packer L. Lipoate prevents glucose-induced protein modifications.  Free Rad Res Comms 1992;17:211-7.
10. Fuchs J, Schofer H, Milbradt R, et al. Studies on lipoate effect on blood redox state in human immunodeficiency virus infected patients.  Arzneim Forsch 1993;43:1359-1362.
11. Baur A, Harrer T, Peukert M. Alpha-lipoic acid is an effective inhibitor of human immuno-deficiency virus (HIV-1) replication  Klin Wochenschr 1991;69:722-4.
12. Suzuki YJ, Aggarwal BB, Packer L. Alpha-lipoic acid is a potent inhibitor of NF-kB activation in human T cells.  Biochem Biophys Res Comm 1992;189:1709-15.