Alpha Lipoic Acid
Lipoic acid, also known as alpha-lipoic acid, is a sulfur-containing fatty acid. It is found inside every cell of the body, where it helps generate the energy that keeps us alive and functioning. Lipoic acid is a key part of the metabolic machinery that turns glucose (blood sugar) into energy for the body's needs.
Lipoic acid is an antioxidant, which means that it neutralizes naturally occurring but harmful chemicals known as free radicals. Unlike other antioxidants, which work only in water or fatty tissues, lipoic acid is unusual in that it functions in both water and fat. By comparison, vitamin E works only in fat and vitamin C works only in water. This gives lipoic acid an unusually broad spectrum of antioxidant action.
Antioxidants are a bit like kamikaze pilots, sacrificing themselves to knock out free radicals. One of the more interesting findings about lipoic acid is that it may help regenerate other antioxidants that have been used up. In addition, lipoic acid may be able to do the work of other antioxidants when the body is deficient in them.
It is thought that certain nerve diseases are at least partially caused by free radical damage. Thanks to its combined fat and water solubility, lipoic acid can get into all the parts of a nerve cell and potentially protect it against such damage. This is the rationale for studies on the potential benefits of lipoic acid for diabetic neuropathy.
As an oral supplement alpha-lipoic acid seems to reduce symptoms of peripheral neuropathy in diabetes patients, reducing symptoms such as burning, pain, numbness, and prickling of the feet and legs as well as improving sensation. There is evidence that alpha-lipoic acid supplements may also help diabetic patients by lessening damage of the heart, kidneys and small blood vessels. Taking alpha-lipoic acid (300 to 1,200 mg daily) also seems to improve insulin sensitivity and blood sugar control in people with type 2 diabetes, although it may only slightly reduce levels of glycosylated hemoglobin (HbA1c) according to results of 6-month study comparing alpha-lipoic acid to placebo (Porasuphatana, Asia Pac J Clin Nutr 2012).
Alpha-lipoic acid was shown to increase weight and fat loss in a study of 77 healthy, but sedentary, overweight/obese women (ages 20 to 50) on a reduced-calorie diet. Those who took alpha-lipoic acid (300 mg per day), or a combination of alpha-lipoic acid and the omega-3 fatty acid EPA (1,300 mg per day) for 10 weeks lost significantly more weight (an average of 15 lbs. and 14 lbs., respectively), compared to those who took EPA only, or a placebo (average weight loss of 12 lbs. and 11.5 lbs., respectively) (Huerta, Obesity 2015). The women who took alpha-lipoic acid alone or with EPA also lost significantly more body fat than those who took EPA only, or a placebo. The alpha-lipoic acid was taken as a single 100 mg capsule with breakfast, lunch and dinner. The EPA, (433.3 mg EPA was also taken at those times. Larger and longer studies are needed to confirm these effects. Some preliminary evidence suggests alpha-lipoic acid may aid weight loss by promoting the breakdown of fat and inhibiting the formation of new fat cells (Fernandez-Galilea, J Lipid Res 2012; Carrier, J Human Nutr Food Sci 2013).
A placebo-controlled, 1-year pilot study of 34 adults with mild to moderate impairment from Alzheimer's disease found that alpha lipoic acid and fish oil slowed the decline in subjects' cognitive functioning. The combination also slowed the decline in subjects' ability to perform daily activities, as did fish oil alone, but not alpha-lipoic acid alone. The participants normally ate fish no more than once per week and most continued to take Alzheimer's medications. A capsule of alpha-lipoic acid (600 mg) was taken each morning along with 2 fish oil capsules (each containing 1 gram of fish oil providing 325 mg EPA and 225 mg DHA in the triglyceride form). Another fish oil capsule was taken with lunch (Shinto, J Alzheimers Dis 2014). Although earlier studies have not shown a benefit with omega-3 fatty acids in Alzheimer's disease, this study differed in that the fish oil had a high ratio of EPA to DHA.
The typical dose for treating diabetes, peripheral neuropathy associated with diabetes, and cardiac autonomic neuropathy is 200 to 400, taken 2-3 times daily (for a total daily dose ranging from 600 mg to 1,200 mg). For weight loss, 100 mg alpha-lipoic acid (taken three times per day with meals), along with a reduced-calorie diet, has shown to be beneficial. For use as a general antioxidant, a lower dose (20 to 50 mg daily) is commonly recommended
Lipoic acid appears to have no significant side effects at dosages up to 1,800 mg daily.
Safety for young children, women who are pregnant or nursing, or those with severe liver or kidney disease has not been established.