| Dietary sources | |
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Alpha-lipoic acid is a sulphur-containing fatty acid, which in food primarily comes from enzymes containing lipoamide and is bound to the amino acid lysine. |
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| Physiological effects | |
| Energy metabolism |
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| Nerve system |
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| Glucose metabolism |
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| Antioxidant |
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| Liver metabolism |
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| Endothelium |
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| Requirements | |||
| Alpha-lipoic acid is a conditionally essential nutrient. Under normal circumstances it can be sufficiently synthesized by the body, but in case of illness or under special physiological conditions the synthesis may be inadequate. | |||
| Increased need | Increased oxidative stress (e.g. from smoking, sports), alcohol abuse, diabetes mellitus, free radical associated diseases such as multiple sclerosis, Alzheimer's disease, liver regeneration and heavy metal excretion; | ||
| Groups at risk of deficiency | Diabetes mellitus, heavy metal exposure | ||
| A universal antioxidant |
| Alpha lipoic acid (thioctic acid) is a sulphur-containing universal antioxidant which is involved in many metabolic processes in lipophilic and hydrophilic environments. It is now assumed that alpha lipoic acid is one of the conditionally essential nutrients that are sufficiently synthesized by the body under normal circumstances, but whose biosynthesis appears to be inadequate in the case of disease or under special physiological conditions (1). |
| Alpha lipoic acid and diabetic complications |
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Recently, it has been established that oxidative stress is the main cause for the development of diabetic polyneuropathy. This is supported by the fact that the occurrence of free radicals in diabetics correlates with the severity of neuropathy (2). Polyneuropathies are sensory disorders, especially in the hands and feet, motor impairments such as muscle weakness and paralysis and disorders of the autonomic nervous system, which can manifest themselves in reduced intestinal peristalsis, diarrhea, vomiting or impotence. Together with microangiopathic changes in the blood vessels that supply the nerves, they lead to complex symptoms that significantly affect the overall prognosis of the diabetic. Alpha lipoic acid inhibits these processes and can prevent the development of complications or improve existing symptoms. In controlled clinical studies, oral administration of 800 mg/day of ALA over 4 months significantly alleviated neuropathic disorders (3). Nerve conduction velocity was increased (4) and cardiac autonomic myocardial ischemia was improved by an increase in heart rate variability (5). Peripheral insulin sensitivity and glucose uptake are also enhanced by alpha lipoic acid (6). |
| Alpha Lipoic Acid and Chronic Metal Intoxication |
| Another indication is chronic metal intoxication, in which alpha lipoic acid is used to remove heavy metals and strengthen liver function. It is also an integral part of detoxification therapies for "multiple chemical sensitivity"(7). |
| Alpha-lipoic acid for liver cell protection |
| Alpha lipoic acid not only seems to play an important role in detoxification, but also in the regenerative capacity of liver cells. This ability is based on its role as an antioxidant and on its function in the synthesis of glutathione. In an animal study, rats fed with polyunsaturated omega-6 fatty acids (n-6 PUFA) experienced fatty liver, apoptosis, fibrosis and general inflammation. All negative effects of n-6 PUFAs feeding could be significantly reduced by the administration of alpha lipoic acid (8). |
| Impact on | Symptoms |
| Energy metabolisml | Mitochondrial dysfunction with an increase in lactate and pyruvate |
| Oxidative stress | Increased risk of radical-associated diseases Oxidation of LDL particles in the blood and PUFAs in the cell membranes |
| Diabetic metabolism | Hyperglycemic polyneuropathies, angiopathies and nephropathies |
| Effect | Indication | Dosage |
| Physiological effects at a low intake |
Adjuvant therapy for diabetic complications such as polyneuropathy, diabetic foot and cataracts | 200 - 600 mg/d |
| Supports detoxification and heavy metal elimination as well as liver protection | 200 - 600 mg/d | |
| General mode of administration | |
| When |
Alpha lipoic acid should be taken 30 - 45 minutes before a meal as food reduces the bioavailability. |
| Side Effects | |
| In rare cases, gastrointestinal complaints (nausea, diarrhea) may occur. Due to the improvement of glucose utilization, a drop in blood sugar levels with accompanying dizziness and headaches may occur under certain circumstances. | |
| Contraindications | |
| The use of this supplement during pregnancy should be discouraged or only carried out under medical supervision due to lack of research. | |
| Drug interactions | |
| Antidiabetics (e.g. metformin, glimepiride) | The blood sugar-lowering effect of insulin and oral antidiabetics can be enhanced by alpha-lipoic acid. |
| Cholinesterase inhibitors (e.g. Donopezil, Rivatsigmin) | Alpha-lipoic acid extends the anti-dementia effect of cholinesterase inhibitors. |
| Nutrient interactions | |
| Trace elements | Calcium, iron, magnesium, manganese, zinc and copper form complexes when taken simultaneously and lead to a reduction in the oral bioavailability of alpha-lipoic acid. This effect is used to eliminate heavy metal poisoning. |
| Vitamins | Alpha-lipoic acid regenerates vitamin C and vitamin E and supports their antioxidant effects. |
| Vitaminoids | Coenzyme Q10 and alpha-lipoic acid support each other in their antioxidative effects. |
| Description |
| Vitaminoid |
| Description and related substances |
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| References |
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1) Kendler, B. S. 2006. Supplemental Conditionally Essential Nutrients in Cardiovascular Disease Therapy. The Journal of Cardiovascular Nursing 21(1):9–16. doi:10.1097/00005082-200601000-00004. 2) Ziegler, D. 2004. Thioctic Acid for Patients with Symptomatic Diabetic Polyneuropathy. Treatments in Endocrinology 3(3):173–189. doi:10.2165/00024677-200403030-00005. 3) Bonnefont-Rousselot, D. 2004. The Role of Antioxidant Micronutrients in the Prevention of Diabetic Complications. Treatments in Endocrinology 3(1):41–52. doi:10.2165/00024677-200403010-00005. 4) Negrisanu, G. et al. 2000. Effect of thioctic acid on diabetic somatic neuropathy. Diabetes Research and Clinical Practice 50: 268. doi:10.1016/s0168-8227(00)80912-2. 5) Gröber, U. 2002. Orthomolekulare Medizin. ein Leitfaden für Apotheker und Ärzte. Stuttgart (Wiss. Verlag-Ges.). 6) Hahn, A. et al. 2005. Ernährung. Physiologische Grundlagen, Prävention und Therapie. 7) Fuchs, N. 2001. Mit Nährstoffen heilen. Eine Einführung in die komplexe orthomolekulare Nährstoff-Therapie. (Reglin). 8) Kaya-Dagistanli, F. et al. 2013. The effects of alpha lipoic acid on liver cells damages and apoptosis induced by polyunsaturated fatty acids. Food and Chemical Toxicology 53:84–93. doi:10.1016/j.fct.2012.11.026.
Stargrove, M. B. et al. Herb, Nutrient and Drug Interactions: Clinical Implications and Therapeutic Strategies, 1. Auflage. St. Louis, Missouri: Elsevier Health Sciences, 2008. Gröber, U. Mikronährstoffe: Metabolic Tuning –Prävention –Therapie, 3. Auflage. Stuttgart: WVG Wissenschaftliche Verlagsgesellschaft Stuttgart, 2011. Gröber, U. Arzneimittel und Mikronährstoffe: Medikationsorientierte Supplementierung, 3. aktualisierte und erweiterte Auflage. Stuttgart: WVG Wissenschaftliche Verlagsgesellschaft Stuttgart, 2014.
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