Alpha-lipoic acid (also known as lipoic acid, thioctic acid, or ALA) is a vitamin-like chemical called an antioxidant. Researchers discovered the importance of alpha-lipoic acid in the 1950s, and recognized it as an antioxidant in 1988. In humans, Alpha lipoic acid is synthetized by the liver and other tissues with high metabolic activity; heart, kidney. ALA is absorbed from the small intestine and distributed to the liver via the portal circulation and to other tissues in the body via the systemic circulation. Alpha Lipoic Acid is not to be confused with the alpha-linolenic acid (called ALA) found in flax and canola oil.
Yeast, beef, and organ meats, broccoli, spinach, and potatoes are good sources of alpha-lipoic acid.
Alpha Lipoic Acid Therapeutic Benefits
ALA has 2 important functions in body. First, it serves as a coenzyme in several metabolic pathways. Second, it is an powerful antioxidant.Alpha Lipoic acid is a coenzyme for a group of enzymes responsible for the eventual conversion of fats, carbohydrates and proteins in to biological energy. The body needs ALA to produce energy. It plays a very important role in the energy-producing structures in cells. Alpha lipoic acid is essential for the production of cellular energy in the form of ATP, therefore delivers a boost of energy. ALA increases the formation of glutathione. Glutathione is an important antioxidant that helps the body eliminating deleterious substances. ALA was effectively used to treat children exposed to radiation from the Chernobyl accident in the former Soviet Union.
Alpha-lipoic acid is a naturally occurring dithiol compound that functions as a cofactor for many mitochondrial enzymes involved in energy metabolism. ALA is part of 2 enzyme systems; alpha-ketoglutarate dehydrogenase and pyruvate dehydrogenase. Functions as a co-enzyme cofactor in the alpha-ketoglutarate dehydrogenase and pyruvate dehydrogenase mitochondrial enzyme complexes in the production of energy.
Alpha-Lipoic acid possesses strong antioxidant activity. The reduced form dihydrolipoic acid (DHLA) is more potent than lipoic acid. ALA protects mitochondria by removing free radicals and improves the recycling of other antioxidants. Unlike other antioxidants which are either fat soluble or water soluble, Alpha-lipoic acid simultaneously acts as both a fat and a water-soluble antioxidant in the body. Because of its two-fold interactions with both water-soluble (vitamin C) and fat-soluble (vitamin E) substances, Alpha-lipoic acid has been shown to avoid lack of both vitamins in both human and animal studies. ALA administration has been shown to be useful in a number of oxidative stress models such as diabetes, ischemia-reperfusion injury, cataract formation, HIV activation, neurodegeneration, and radiation injury.
Diabetes is a condition characterized by high levels of sugar in the blood. ALA has the potential to prevent diabetes, influence glucose control, and avoid chronic hyperglycemia-associated complications such as neuropathy. A placebo-controlled study of 72 patients with type 2 diabetes mellitus found that oral administration of Alpha-lipoic acid at doses of 600 mg/day, 1,200 mg/day or 1,800 mg/day improved insulin sensitivity by 25% after 4 weeks of therapy.
In a study of a controlled-release form of oral Alpha lipoic acid, 15 patients with type 2 diabetes mellitus took 900 mg/day for 6 weeks and 1,200 mg/day for another 6 weeks, in addition to their current drugs. At the end of 12 weeks, plasma fructosamine concentrations decreased by approximately 10% from baseline. A clinical trial in 13 people with type 2 diabetes mellitus found that a single intravenous infusion of 1000 mg of Alpha-lipoic acid improved insulin-stimulated insulin sensitivity by 50% compared to a placebo infusion. In a study of 20 patients with type 2 diabetes mellitus, intravenous infusion of 500 mg/day of Alpha lipoic acid for 10 days also improved insulin sensitivity when measured 24 hours after the last infusion.
Peripheral neuropathy is a condition characterized by pain and numbness in the hands and feet that occurs in people with diabetes, nerve pressure, vitamin deficiency, kidney or liver disease and alcoholism. More than 20% of diabetic patients develop peripheral neuropathy. Oral and Intravenous (IV) alpha-lipoic acid has been used for years to treat peripheral neuropathy in Germany. The current studies, suggests therapy with 600 mg/day of intravenous Alpha-lipoic acid for 3 weeks significantly reduces the symptoms of diabetic peripheral neuropathy.
In a study diabetic individuals suffering from peripheral neuropathy who were given 200 mg of Alpha-lipoic acid intravenously for 21 days reported a decrease in pain. A study in Austria found that more than half of the cancer patients who took Alpha-lipoic acid after getting the chemotherapy drug oxaliplatin reported an reduction in neuropathy symptoms. In a study, oral with 1,200 mg/day of Alpha-lipoic acid for 6 weeks improved a measure of capillary perfusion in the fingers of eight diabetic patients with peripheral neuropathy.
A randomized, double-blind, placebo-controlled study in 181 patients with diabetic neuropathy found that oral with 600 mg/day, 1,200 mg/day, or 1,800 mg/day of Alpha-lipoic acid for 5 weeks significantly improved neuropathic symptoms. In this study, the 600 mg/day dose was as effective as the higher doses. A meta-analysis that combined the results of 4 randomized controlled trials, including 1,258 diabetic patients, found that therapy with 600 mg/day of intravenous Alpha-lipoic acid for 3 weeks significantly reduced the symptoms of diabetic neuropathy to a clinically meaningful degree.
Alpha lipoic acid was used in the 1970s as a therapy for various forms of hepatitis. The scientists administered ALA intravenously to 79 people with acute and serious liver damage at medical centers across the United States, and 75 recovered full liver function. According to a study ALA inhibits the expression of matrix metalloproteinase in cancer cells, which may play a role in liver cancer invasion and metastasis. In a study, published in a 2008 issue of “Hepatology”, determined that Alpha-lipoic acid prevented fatty liver disease and may be used to prevent nonalcoholic fatty liver disease in insulin-resistant patients. Amanita is a extremely poisonous mushroom that causes liver damage. ALA infusions were used in the therapy of amanita mushroom poisoning in 75 patients between 1974 and 1978. Normally, up to 50% of patients recover without intervention; but, 89 % recovered after ALA infusion.
This combination of Alpha lipoic acid, silymarin, and selenium replenishes glutathione stores, promotes liver cell regeneration, and puts the brakes on viral replication. Dr. Berkson has utilized an antioxidant protocol consisting of alpha-lipoic acid 300mg, twice a day; oral selenium, 200 mcg, twice a day; and oral silymarin, 300 mg per day. Dr. Berkson reported his triple-antioxidant protocol in 1999, in the content of a pilot study involving 3 patients with cirrhosis, portal hypertension, and esophageal varies related to HCV. All 3 were candidates for liver transplant. After a year on Alpha lipoic acid, silymarin, and selenium, all were healthy, demonstrated improved hepatic function. (Also to the Alpha-lipoic acid, selenium and silymarin, Dr. Berkson recommends a B vitamin complex because high dose Alpha-lipoic acid will deplete thiamine, niacin and riboflavin.)
Animal-based study shows that animals treated with ALA suffered less brain damage and had 4-times greater survival rate after a stroke than animals who didn’t receive Alpha-lipoic acid.
Alpha-lipoic acid is one of the antioxidants that can pass the blood brain-barrier, which enables it to protect brain tissue and prevent free-radical damage. ALA may have a favorable effect on patients with Alzheimer’s disease and other types of memory dysfunction secondary to trauma or cerebral vascular accident. By decreasing oxidative damage in the central nervous system, Alpha-lipoic acid may reduce the severity of central nervous system disorders. ALA reduces amyloid-beta-induced inflammation and improves brain cells production of the chemical signaling molecules called neurotransmitters.
Researchers believe that Alpha-lipoic acid may increase the production of acetylcholine, an essential nervous system messenger that is deficient in the brains of Alzheimer’s disease patients. A 2007 research in Journal of Neural Transmission showed that high doses of Alpha-lipoic acid slowed Alzheimer’s progression to a greater degree than standard therapy. A small study involving 9 patients showed that there might be a positive effect in using Alpha-lipoic acid in Alzheimer’s disease. Six-hundred milligrams per day of Alpha-lipoic acid for as many as 14 months has reportedly allowed Alzheimer’s patients to maintain scores on neuropsychological tests commonly used to assess Alzheimer’s disease patients.
According to Dr. Lester Packer at the University of California in Berkeley, ALA may have a role in amyotrophic lateral sclerosis, multiple sclerosis, head injuries, and spinal cord damage. Multiple sclerosis is a neurodegenerative and demyelinating disease of central nervous system. Alpha-lipoic acid has been examined as an effective treatment in a rat model of multiple sclerosis and experimental autoimmune encephalomyelitis. Alpha-lipoic acid dose dependently prevented the development of clinical signs in this model.
Alpha-lipoic acid may support healthy vision and help prevent and treat glaucoma and cataracts. The efficacy of ALA was analyzed in a study involving patients with open-angle glaucoma. Notable improvements were observed with respect to both the biochemical measures and visual function as compared with the control group receiving only local hypotensive treatment.
A study revealed that the combination of Alpha-lipoic acid and vitamin E helped prevent retinal cell death in animals with retinitis pigmentosa. The enzyme aldose reductase plays an substantial role in the development of cataracts in diabetes. ALA inhibited aldose reductase activity in the rat lens. In other animal study, Alpha lipoic acid inhibited cataract formation experimentally induced by buthionine sulfoximine, an inhibitor of glutathione synthesis. ALA was administered to 75 participant with open-angle glaucoma at dosages of either 75 mg daily for 2 months or 150 mg daily for one month. The important improvements in the biochemical parameters of glaucoma and visual function were observed in the group receiving 150 mg ALA.
Alpha-lipoic acid inhibits replication of HIV by reducing the activity of reverse transcriptase, the enzyme responsible for manufacturing the virus from the DNA of lymphocytes. Experimental results show that lipoic acid is an effective inhibitor of human immuno-deficiency virus (HIV-1) replication. In one study, it was found that therapy of immune system cells called the T cells with ALA significantly increased their glutathione levels. HIV patients are known to have low tissue levels of glutathione.
ALA blocks the activation of a substance called NF-kappa B, which is essential for the transcription of the HIV virus. ALA may play an important therapeutic role for HIV-infected people. In a study with HIV-infected participants, with ALA provided a variety of advantages related to antioxidant status, T-helper lymphocytes, and the T-helper/ suppressor cell ratio .One small study demonstrated a combination of effects from supplementation with ALA including increases in CD4 cells, increases in blood levels of vitamin C and glutathione, and reduction in the body compounds that result from oxidative stress. Other a study was carried out in 33 HIV-infected individuals with a history of highly active antiretroviral treatment (HAART) unresponsiveness to test the hypothesis of whether supplement with Alpha-lipoic acid would increase blood total glutathione and improve immune T-cell function. After six months of therapy, the mean whole blood total glutathione level in the ALA-treated group increased significantly compared with placebo. In response to the CD3 monoclonal antibody, lymphocyte proliferation decreased 66% in the placebo group over 6 months, compared with a 3.7-fold enhancement in the anti-CD3 response in the ALA-therapy group.
ALA appears capable of chelating certain metals. In vitro and animal studies suggest ALA might be a useful component in the therapy of heavy metal toxicity, particularly toxicity involving cadmium, lead, copper, or mercury. In animal-based studies, Alpha lipoic acid has been shown to provide protection against arsenic poisoning and to safeguard the liver against the effects of cadmium exposure. Other study demonstrated that ALA helped protect the delicate nervous system against the deleterious effects of mercury poisoning.
A study on mercury intoxication revealed an injection of 10 mg/kg/day Alpha-lipoic acid in rats inoculated with 1 mg/kg/day mercuric chloride prevented damage to nerve tissue caused by lipid peroxidation. In one study an intraperitoneal injection of 25 mg/kg Alpha-lipoic acid given to rats for 7 days was able to significantly alter the oxidative stress induced by lead toxicity.
Recommended oral therapeutic dosages of ALA range from 600 mg-1800 mg daily. Since taking Alpha-lipoic acid with a meal decreases its bioavailability, it is usually recommended that ALA be taken on an empty stomach.