Alpha Lipoic Acid (ALA)

(Our thanks to excerpts from David Wolfson, N.D. Nutrition Science News)

Most of us are aware of anti-oxidants like vitamins C and E.  However, there is another antioxidant with a wider range of benefits.  Lipoic acid (also known as alpha-lipoic acid, ALA) was first discovered in 1951 – and things have been getting better ever since.

Our bodies need the help of lipoic acid:

• To be efficient in producing energy from carbohydrates or fats.
• As an antioxidant, protecting our cells from oxygen damage.
• Recycling several different antioxidants, including vitamins E and C.

Antioxidant

Antioxidants typically come in two varieties: water soluble and fat soluble.  A few, such as lipoic acid, are both. This is why lipoic acid is often termed an “universal antioxidant.”

Vitamin E is associated with fat-based areas of the cell, vitamin C is found primarily in water-based areas.  Because lipoic acid can function equally well in both areas, it can support the activity of both types of vitamins.

Like other antioxidants, lipoic acid has the ability to scavenge the body for disease-causing free radicals.  Free radicals cause damage by “stealing” electrons from other molecules such as DNA, fats and proteins.  Antioxidants prevent this damage by neutralizing the radical’s reactivity.

However, that appears to only scratch the surface of this supplement’s benefits.

Four Main Functions

Several decades of research on lipoic acid have enabled researchers to identify four main areas of this supplement’s abilities:

Free radical scavenging: Lipoic acid is capable of neutralizing a wide variety of free radicals. [2] These types of radicals are believed to play a significant role in disease processes such as hardening of the arteries (atherosclerosis), cancer, cataract formation and diabetes.

Metal chelation: Lipoic acid can effectively prevent intoxication with toxic metals such as arsenic, cadmium, lead and mercury.

Antioxidant regeneration: Antioxidants can often be regenerated with the help of other antioxidants.  Glutathione, for example, can regenerate vitamin C.  Vitamin C can, in turn, regenerate vitamin E.  Lipoic acid regenerates a variety of antioxidants including glutathione, vitamins C and E, and the mitochondrial antioxidant coenzyme Q10. [4]

Damaged molecule repair: Studies show that lipoic acid plays a role in the repair of oxidative damaged molecules. [5]

Specific Applications

Cataract protection: Additional studies have demonstrated that lipoic acid might also be protective against cataract formation.  Cataracts are associated with reduced antioxidant activity in the lens of the eye, and lipoic acid is known to regenerate several important lens antioxidants, including glutathione.

Maintaining supplies of other antioxidants:  Lipoic acid has been shown to prevent deficiency of both vitamins C and E.  It appears to recycle these antioxidants!  Other antioxidants, also benefit, including coenzyme Q, and glutathione.  Lipoic acid is required for the maintenance of vitamin C supplies.

Protection against irradiation: In one very interesting Russian study (Korkina, below) involving Chernobyl radiation victims, lipoic acid was shown to reduce free radical damage caused by radiation exposure.

HIV treatment: Based in its antioxidant regenerative properties, lipoic acid has been shown to improve the antioxidant status in a group of 11 HIV-infected patients. (Fuchs, below).

Diabetes therapy: Perhaps the most widely noted clinical application of lipoic acid is in the treatment of diabetes and its complications. Diabetics frequently suffer from peripheral neuropathy, a degenerative nerve condition that involves numbness, tingling and sometimes burning pain in the extremities. Studies indicate lipoic acid can help reduce these nerve dysfunction symptoms.

Besides relieving neuropathy, lipoic acid offers diabetics the additional benefit of reducing insulin resistance, the inability of insulin receptors to effectively uptake glucose at the cellular level.

Lipoic acid sits at the end of a process called glycolysis, which our cells use to create energy from sugars and starches. This helps explain its clinical use with conditions like diabetes, where processing of sugar is disrupted.  Studies indicate that lipoic acid can reduce hyperglycemia and may be a safer alternative to oral hypoglycemic agents.

What Factors Might Contribute to a Deficiency of this Nutrient?

Individuals who eat no animal products may be at higher risk for lipoic acid deficiency than individuals who do. Vegetarians who eat no green leafy vegetables may also be at special risk, since the chloroplasts in these leaves house most of the lipoic acid.

Since lipoic acid protects proteins during aging, older individuals may be at greater risk of deficiency.
Similarly, because lipoic acid is used to help regulate blood sugar, individuals with diabetes may be at special risk of deficiency.

Individuals with poor protein intake, and particularly those with poor intake of the sulfur-containing amino acids (the building blocks of protein that contain sulfur, namely, methionine, cysteine, and taurine) may also be at higher risk of lipoic acid deficiency. The reason for this connection is simple: lipoic acid gets its sulfur atoms from these sulfur-containing amino acids.

Because lipoic acid is absorbed primarily through the stomach, individuals with stomach disorders (for example, hypochlorhydria, or low stomach acid) may also be at increased risk of deficiency.

A mere 1 g of lipoic acid has been shown to exert numerous therapeutic applications, and it has proven to be virtually free of side effects. Furthermore lipoic acid is capable of chelating heavy metals, regenerating other antioxidants, repairing damaged molecules and mitigating the oxidative damage caused by free radicals.

In his book on lipoic acid, The Antioxidant Miracle (John Wiley & Sons, 1999), Lester Packer, Ph.D., one of the foremost experts on antioxidants, recommends regular daily supplementation with 100 mg of lipoic acid.  People with established health problems may wish to increase their daily dose to the 400 to 600 mg range, or work with their health care practitioner to achieve the optimal dose for their particular condition.

References:

1. Fuchs J, et al., editors. Lipoic acid in health and disease. New York: Marcel Dekker Inc.; 1997.

2. Biewanga G, et al. The pharmacology of the antioxidant lipoic acid. Gen Pharmac 1997;29(3):315-31.

3. Sumathi R, et al. Relationship between glutathione and DL alpha-lipoic acid against cadmium-induced hepatotoxicity. Jpn J Med Sci Biol 1996;49(2):39-48.

4. Packer L, et al. Alpha-lipoic acid as a biological antioxidant. Free Rad Biol Med 1995;19(2):227-50.

5. Spector A, et al.Thioredoxin fragment 31-36 is reduced by dihydrolipoamide and reduces oxidized protein. Biochem Biophys Res Commun 1988;150:156-62.

6. Shih JCH. Atherosclerosis in Japanese quail and the effect of lipoic acid. Fed Proc 1983;42:2494-7.

7. Maitra I, et al. Alpha-lipoic acid prevents buthionine sulfoximine-induced cataract formation in newborn rats. Free Rad Biol Med 1995;18:823-9.

8. Korkina L, et al.Antioxidant therapy in children affected by irradiation from the Chernobyl nuclear accident. Biochem Soc Trans 1993;21:314S.

9. Fuchs J, et al.Studies on lipoate effects on blood redox state in human immunodeficiency virus infected patients. Arzneim-Forsh 1993;43(2):1359-62.

10. Ziegler D, et al. Treatment of symptomatic diabetic peripheral neuropathy with the antioxidant alpha-lipoic acid: a 3-week multicentre randomized controlled trial (ALADIN study). Diabetologia 1995;38:1425-33.

11. Jacob S, et al. Improvement of insulin-stimulated glucose disposal in type 2 diabetes after repeated parenteral administration of thioctic acid. Exp Clin Endocrinol Diabetes, 1996;104:284-8.

12. Konrad T, et al. Alpha lipoic acid treatment decreases serum lactate and pyruvate concentrations and improves glucose effectiveness in lean and obese patients with type 2 diabetes. Diab Care 1999;22:280-7.

13. Jacob S, et al. Oral administration of RAC-alpha-lipoic acid modulates insulin sensitivity in patients with type-2 diabetes mellitus: aplacebo-controlled pilot trial. Free Rad Biol Med 1999;27(3/4):309-14.

14. Packer L, Colman R. The antioxidant miracle. New York (NY): John Wiley & Sons Inc.; 1999. p 32