Alpha Lipoic Acid - How it Works

Today's post from askville.amazon.com (see link below) is a very useful one for those people considering taking Alpha Lipoic Acid to help with their neuropathy symptoms. Along with Acetyl L Carnitine, Alpha Lipoic Acid is one of the commonest supplements taken to treat neuropathic problems. It is a powerful anti-oxidant which carries a lot of ambitious claims with it. Whether these are justified remains to be seen. It is still being evaluated across the world, especially in relation to the brain and the nervous system. As with most supplements, cost is an issue (it can be very expensive) and high doses are generally recommended; so it's worthwhile knowing what you're paying for and what it might do for you.

Alpha-Lipoic Acid and Peripheral Neuropathy
Author: John A. Senneff
Source: Nutrients for Neuropathy, Volume 3 in the Numb Toes Series

There are probably more studies attesting to the benefits of alpha-lipoic acid (ALA), also known as lipoic acid or thioctic acid, for dealing with peripheral neuropathy than studies for any other nutrient. ALA is a sulfur containing fatty acid found inside every cell of the body, where it helps generate the energy that keeps us alive and functioning. This nutrient is a key part of the metabolic machinery that turns glucose (blood sugar) into energy for the body's needs.

Dr. Lester Packer, who heads the Department of Molecular & Cell Biology at the University of California, Berkley, calls ALA a "universal antioxidant." In addition to its remarkable abilities as a natural antioxidant, protecting nerves from oxidative damage and inflammation, it has great facility for raising levels of the enzyme glutathione, itself a powerful antioxidant. Some research also suggests that the nutrient may be able to do the work of other antioxidants when the body is deficient in them. As a corollary, it has been demonstrated that ALA can regenerate other antioxidants such as vitamins A and C as well as coenzyme Q10.

ALA offers dual antioxidant protection because it is both fat and water soluble. Water solubility means that it works inside the nerve cell. Its fat solubility permits it to work outside the cell, at the membrane level. This double action on both sides of nerve cell walls is said to result in a stronger defense against damaging free radicals. (As mentioned before, we encounter these harmful molecular fragments every day through exposure to the sun's rays, automobile exhaust, smoke from various sources, and air pollution in general.)

The classic early study on the efficacy of alpha-lipoic acid for peripheral neuropathy, referred to as the ALADIN study (Alpha-Lipoic Acid in Diabetic Neuropathy), was performed in Dusseldorf, Germany, in 1995. The effects of ALA were studied in a 3-week multi-center, randomized, double-blind placebo-controlled trial, in 328 non-insulin-dependent diabetic patients with symptomatic peripheral neuropathy. These patients were randomly assigned to treatment with intravenous infusion of alpha-lipoic acid at three dose levels (1200, 600, or 100 mg), or placebo. Neuropathic symptoms (pain, burning, paresthesia, and numbness) were scored at baseline and at each visit. Based on the study results the investigators said that using intravenous treatment at a dose level of 600 mg daily was effective in reducing symptoms of peripheral neuropathy without causing significant adverse reactions.

Clinical evidence from various parts of the world continues to support the use of ALA for diabetic and other peripheral neuropathies. A randomized, double-blind study at the University of Zagreb in Croatia in 1999, concluded that after the daily administration of 600 mg of ALA to one group of diabetic patients and 1200 mg to another for a period of two years (65 patients in all), ALA "appeared to have a beneficial effect on several attributes of nerve conduction." (The investigators did qualify their opinion by saying that although neuropathic symptoms seemed to have improved over the 24 month study period, the "long-term response remains to be established.")

A three-week study performed in Dusseldorf, Germany, reached a similar conclusion. The patients with diabetic neuropathy enrolled there were given 600 mg of ALA three times daily. Researchers made the point that not only were neuropathy pain symptoms lessened but the nutrient was well tolerated.

Russian investigators also found symptomatic improvement in a group of 29 patients with diabetic neuropathy after 14 days of ALA.

Similarly, American investigators at the Mayo Clinic in Rochester, Minnesota, found that after the administration of ALA, peripheral nerve function improved in rats in which diabetic neuropathy had previously been induced.

A more recent study delved into the nitty-gritty of the way ALA offers antioxidant protection. Researchers in Germany investigated the effects of the nutrient on the body's microcirculation system for carrying oxygen to nerve cells. (This system consists of blood vessels such as capillaries with a diameter of less than 300 micrometers. Peripheral neuropathy is sometimes associated with a lack of blood circulation to the nerve cells.) The investigators concluded that microcirculation was benefited by the administration of either 600 mg or 1200 mg daily over a six-week period. In technical terms they found that there was a decrease in the "time to peak capillary blood cell velocity,"--a marker in determining oxygen transport benefit.

A study performed at the University of Texas Southwestern Medical Center at Dallas also examined the manner in which ALA functions as an antioxidant, concluding it does so because "it decreases plasma- and LDL oxidation."

Finally a meta analysis in Germany (which pre-dated the Texas study) examined the results of 15 clinical trials. The conclusion, based on all 15, was that short-term (three weeks) treatment of diabetic neuropathy, using 600 mg per day of ALA, "appeared to reduce the chief symptoms" of neuropathy. Moreover, the preliminary data indicated to the investigators the "possible long-term improvement in motor and sensory nerve conduction in the lower limbs." The investigators emphasized that these 15 trials revealed a "highly favorable safety profile" for ALA.

A more recent paper, also from Germany and mentioned in the discussion of GLA, again acknowledged the benefits of ALA for the treatment of diabetic neuropathy: "Symptomatic therapy includes alpha-lipoic acid treatment, as the antioxidant seems to improve neuropathic symptoms." (It should be noted that ALA is specifically approved for the treatment of diabetic neuropathy in Germany.)

Incidentally, in addition to painful sensory neuropathies, alpha-lipoic acid is useful with autonomic neuropathies. These disorders, which affect involuntary or semi-voluntary functions such as control of inner organs, are common among people with diabetes and have been reported to be present in up to 40% of Type 2 diabetic patients. Symptoms may include gastroparesis (a condition where the stomach is not emptying properly and characterized by nausea, vomiting, and abdominal distension), sexual dysfunction, low blood pressure when standing up (postural hypotension), and inability to sweat, as well as a variety of cardiac abnormalities.

An earlier German study showed that alpha-lipoic acid caused a significant improvement in irregular heart rate in subjects with autonomic neuropathy. (Richard N. Podell, M.D., who has studied ALA extensively, maintains that this study "provides the first clear evidence that nutritional treatment alone can reverse the course of autonomic neuropathy.")

There is no daily requirement established for ALA, presumably because a healthy body makes enough of it to supply daily energy requirements. However some practitioners recommend supplementation regularly because of its superior antioxidant capabilities; Lester Packer, Ph. D., considered an expert in this area, recommends daily dietary additions of 100 mg.

Many health care professionals recommend dosage levels of 400-600 mg of ALA daily for therapeutic purposes. In fact some go as high as 1200 mg per day. There reportedly have been no serious adverse effects from the use of ALA, even in quite high dosages (up to 1800 mg daily). Minor effects have been mainly allergic skin reactions.

Sources: http://www.diabetessymptom.net/news/news_item.cfm?NewsID=263

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