Alpha-lipoic acid is a naturally occurring substance and can be found in most types of prokaryotic and eukaryotic cells. In humans, alpha-lipoic acid is a cofactor in several multienzyme complexes involved in energy formation, and as alpha-lipoic acid is both water- and fat-soluble, it is present in virtually all parts of the body. As a result, it is often referred to as the "universal antioxidant." In human metabolism, the pyruvate dehydrogenase multienzyme complex lies at the core of the Krebs Cycle, the main energy cycle in the body. As it is a cofactor for the decarboxylation of pyruvate within this particular multienzyme complex, alpha-lipoic acid instantaneously participates in the process of energy production from food. The human body is capable of producing alpha-lipoic acid itself in small amounts. Furthermore the body resorbs this antioxidant from ingested food, like potatoes and meat.

Yet an individual's level of alpha-lipoic acid is actually very low and there is evidence that this level declines further with age. To overcome this issue, supplementation of alpha-lipoic acid is reasonable under any conditions that lead to a decline of the body's antioxidant status, like sports, stress, intake of unbalanced nutrition and during illnesses. The daily dose is about 300 milligrams. According to a number of human studies, this dose is effective as well as safe, provided that a supplement of good quality is used.

Due to its unique chemical structure, alpha-lipoic acid is capable of attaching to so-called free radicals or reactive oxygen species (ROS). Free radicals are highly reactive molecules from numerous origins such as pollution, radiation, alcohol, cigarette smoke or certain drugs. Free radicals can interfere with cell membranes, enzymes or DNA, may cause severe damage to tissues and increase the effects of cell aging and diseases. Alpha-lipoic acid and its reduced endogeneous counterpart, dihydrolipoic acid, are highly potent inhibitors and scavengers of free radicals. Like other antioxidants, e.g. vitamins A, C and E, alpha-lipoic acid interacts with free radicals and converts them to entities, which can no longer harm cell structures. Alpha-lipoic acid is also capable-via its reduced form, dihydrolipoic acid-of recycling other antioxidants like vitamin E, vitamin C, glutathione and coenzyme Q10 and reducing protein glycation, a degenerative process that causes problems like high blood pressure or vascular diseases.

As part of this antioxidant network, alpha-lipoic acid may help alleviate the effects of oxidative stress for the human body. Oxidative stress plays a major role in the development of diabetes and nerve diseases. Thus alpha-lipoic acid is also presumed to be effective in reducing complications associated with type II diabetes as well as protecting nerve cells from damage. Diabetic cells are characterized by high blood glucose contents. The consumption of glucose is carried out by certain enzyme complexes, which employ alpha-lipoic acid as an essential cofactor. Alpha-lipoic acid stimulates the uptake of blood glucose into muscle tissue, increases glycolysis and augments glucose utilization. Furthermore, alpha-lipoic acid inhibits gluconeogenesis. There has also been evidence that it also has a positive influence on insulin action by stimulating insulin sensitivity. As high blood pressure, weight problems or atherosclerosis often accompanies diabetic complications, alpha-lipoic acid supplementation may help to alleviate symptoms associated with these conditions.

In general, alpha-lipoic acid improves the overall cellular function of the human body. As many diseases share an inability of proper cellular function due to cell damage, alpha-lipoic acid might also be beneficial in various complications such as neurological disorders, heart disease or immune malfunction.

Given its unique features, it is not surprising that this universal antioxidant has found widespread use as a dietary supplement, particularly in anti-aging appliances. Especially for the U.S. market, significant growth for alpha-lipoic acid is expected over the next few years. Contributing to this growth are intensive efforts in the R&D departments of the most well recognized nutraceutical companies all over the world. Recent research interests include the improvement of the stability, bioavailability and duration of its efficacy by developing sustained release formulations.

About the authors:
Dr. Schuhbauer and Dr. Pischel are involved in research and development at SKW-Traco Labs, Champaign, IL, which is the result of the union of Traco Labs, Lucas Meyer and SKW Chemicals. Dr. Schuhbauer is based in Trostberg, Germany and has done significant work in the manufacturing process for alpha-lipoic acid and is currently working on chiral building blocks. Dr. Pischel oversees research and development and the technical facilities for Traco Labs, Inc., the North American platform for SKW Nature Products Business Unit BioActives. For more information, contact Dr. Pischel at Ivo.Pischel@tracolabs.com.