<body><h1>Alpha-Lipoic Acid (ALA)</h1><p><br></p><p> syn. Thioctic acid </p><p> syn. 2-dithiolane-3 penatanoic acid</p><p> </p><p> </p><p> </p><h2> Description: </h2><div id=’imgblock’><img data-pointer=’9087’/></div><p> Alpha-lipoic acid (ALA) is a sulfur containing vitamin-like antioxidant. It is obtained in the diet from a number of sources, including yeast, spinach, broccoli, potatoes, and meat.80 The body can readily synthesize ALA as well, which means that it is not considered an essential nutrient. This also excludes any classification as a vitamin, even though it possesses some similarity to the B-complex family. Alpha-lipoic exerts a number of key biological activities that can support optimal metabolism. Its supplementation is commonly used for the support of numerous medical conditions including type-2 diabetes, metabolic syndrome, reduced cognitive function, heavy metal toxicity, and liver poisoning. Alpha-lipoic acid supplements are also used to support exercise, particularly energy and nutrient partitioning.</p><div id=’imgblock’><img data-pointer=’9088’/></div><p> The mechanism of action for alpha-lipoic acid begins with its powerful antioxidant properties.81 ALA is both a water- and fat-soluble substance. This allows it to act as a universal antioxidant, neutralizing free radical products of metabolism in both watery and fatty areas of cells (such as cell fluids and membranes). In contrast, the antioxidant vitamins C & E are only water and oil soluble (respectively), which limits their regions of activity. ALA may also protect these two antioxidant vitamins from metabolism, enhancing their activates. The antioxidant properties of alphalipoic acid may be additionally strengthened due to its own resistance to deactivation, as a primary metabolite of ALA (dyhydrolipoic acid, DHLA) also appears to have strong antioxidant activity. </p><p> Alpha-lipoic acid also exerts a strong influence over blood glucose management, although its exact mode of action in this process is not fully understood. Studies show that this nutrient can increase the sensitivity of skeletal muscle cells to the hormone insulin, responsible for stimulating the uptake of glucose into cells.82 This occurs, at least in part, via an increase in insulin receptor protein content.83 By increasing insulin sensitivity, the body is better able to drive nutrients into muscle cells, and away from storage in adipose (fat) cells, which is typically increased with insulin resistance and diabetes. Alpha-lipoic acid also appears to increase glucose uptake via insulin-independent mechanisms.84</p><p> </p><p> With regard to energy metabolism, alpha-lipoic acid has a number of key activities important to the functioning of cell mitochondria, the principle sites of cellular energy production.85 To begin with, ALA is a cofactor in several mitochondrial enzyme complexes. Among other things, it plays a key role in the citric acid (Krebs) cycle, which involves the oxidation of proteins, fats, and carbohydrates to produce adenosine triphosphate (ATP), the principle fuel for cells.86 Studies also suggest that alpha-lipoic acid is able to protect the mitochondria from lipid peroxidation damage, and enhance electron transport chain complex (ETC) activities.87 These effects, combined with an increase in glucose uptake, may result in an increase in overall energy storage in muscle cells. </p><p> It is important to note that alpha-lipoic acid exists in two enantiomer forms, an R isomer (R-ALA) and an S isomer (S-ALA). Supplement forms of ALA either come as pure R-ALA, or a mixture of both isomers, often in relatively equal quantities. Studies suggest that R-ALA is both better absorbed than S-ALA, and is also more biologically active.88,89 With regard to insulin sensitivity, the S-isomer may even induce resistance to this hormone, countering some of the beneficial effects of R-ALA. While a majority of clinical studies on alpha-lipoic acid have involved the use of a mixture of both isomers, R-ALA is generally regarded as the preferred form of this nutrient to use for supplementation purposes. </p><p> If the metabolic effects of alpha-lipoic acid are consistently carried over into healthy exercise-experienced individuals, this nutrient may offer tangible ergogenic value. Of particular interest to bodybuilders and other resistance-trained athletes may be a positive nutrient partitioning effect, which could help support lean muscle gains and reduce fat retention. This nutrient might also be of interest to a wider range of athletes for its positive effects on energy metabolism and muscle endurance. While empirical evidence does support the use of ALA for certain performance-enhancement purposes, this nutrient has not been extensively studied in a clinical setting for such use. Its potential ergogenic properties remain speculative.</p><h2> Promoted Benefits:</h2><p> Alpha-lipoic acid is promoted to increase muscle insulin sensitivity and nutrient/energy storage. </p><h2> Clinical Studies: </h2><p> This ingredient has been shown in human placebo-controlled studies to improve a metabolic marker (insulin sensitivity) often linked to positive changes in body composition or performance. It has a Clinical Support Rating of 3 (3/5).</p><p> One controlled study examined the effects of alphalipoic acid in a group of patients with type-2 (non-insulin dependent) diabetes.90 An oral dosage of 1,200 mg daily (taken in two 600 mg doses) was administered for a period of four weeks. At the end of supplementation, peripheral insulin sensitivity and glucose disposal were measured with the use of a two-hour hyperinsulinaemic euglycaemic clamp. This is a metabolic measuring technique that steadily infuses insulin along with enough glucose to maintain stable blood sugar levels. The study found that peripheral insulin sensitivity and glucose disposal were significantly increased with the supplementation ALA, and effectively matched levels of control subjects with normal blood glucose control. </p><p> Some animal studies support the potential ergogenic effect of alpha-lipoic acid with more detail. For example, one study examined the effects of a diet supplemented with R-ALA (30 mg/kg of body weight per day) in a group of obese rats.91 The study ran for a period of six weeks. The protocols involved an evaluation of exercise capacity with the use of treadmill exercise. While maximum oxygen consumption (VO2max) did not change, the supplementation of alpha-lipoic acid was shown to increase maximum run time (exercise endurance) by 18%. </p><p> While these results support potential ergogenic action, further research is needed to determine if alphalipoic acid exhibits consistent performance-enhancing properties in trained adults.</p><h2> Empirical Evidence: </h2><p> Alpha-lipoic acid is widely available as a stand-alone nutritional supplement. The feedback on its use as a sport supplement tends to be positive. To begin with, the insulin sensitizing effect of ALA is widely reported and difficult to dispute. For a wide number of users, this reportedly assists with nutrient partitioning into muscle tissue, helping to retain more lean, and less fat, body mass. Very often it is taken both before and after training, in an effort to help shuttle nutrients to skeletal muscle tissue during the important recovery window after exercise. It is unknown if this offers any advantage to regular dosing throughout the day. Some users also report increased muscle endurance and energy, though this benefit appears to be less consistently noticed. A minority of users fail to notice any benefit with regard to the supplementation of alpha-lipoic acid. Whether this is due to an individual insensitivity to the supplement is unknown. Alpha-lipoic acid has an Empirical Evidence Rating of 4 (4/5).</p><h2> Effective Dosage: </h2><p> Based on clinical studies, a dosage of 600-1,800 mg per day (mixed R-ALA/S-ALA) is recommended. A dosage of 300-900 mg is recommended for the pure R-ALA form of alpha-lipoic acid. </p><h2> Side Effects / Safety: </h2><p> Alpha-lipoic acid was well tolerated during clinical studies, with few side effects reported. A small percentage of users notice dermatological issues (rash, itch, and skin allergy) and/or gastrointestinal distress (loose stool, nausea, diarrhea, vomiting). ALA may enhance the hypoglycemic effect of insulin drugs. </p><p> </p></body>
