What it is
Alpha-lipoic acid (ALA), a vitaminlike compound the body produces in small amounts, possesses powerful antioxidant properties. As one of the few antioxidants soluble in both water and fat, ALA disarms free radicals almost anywhere in the body—from watery substances such as blood to fatty substances such as cholesterol. ALA bestows dramatic health benefits in preventing and treating diabetes and diabetic complications. Some evidence also supports its use in treating liver and eye diseases.

How it works
Type 2 (adult-onset) diabetes affects more than 17 million Americans. An additional 41 million have prediabetes, also called metabolic syndrome, and thus are on track for developing a full-blown case of type 2 diabetes. With type 2 diabetes, the pancreas produces the hormone insulin (which allows blood sugar to enter cells), but these cells have become insensitive to insulin and are starved for sugar. In type 1 diabetes, which manifests during childhood, the pancreas does not produce enough insulin.

ALA benefits type 2 diabetics primarily by improving insulin sensitivity and helping insulin in the blood to get sugar into cells (Biochemical and Biophysical Research Communications, 2005, vol. 332, no. 3). In addition, with both types of diabetes, the body is under higher levels of oxidative stress, with harmful free radicals wreaking havoc. Taking ALA lowers this oxidative stress, which would otherwise worsen the diabetes and contribute to complications such as heart disease and nerve damage (Cardiovascular Diabetology, 2005, vol. 4, no. 5).

More than 1 in 3 diabetics develop peripheral neuropathy, nerve damage that results in numbness and pain. The damage is caused by free radicals generated from excessively high blood sugar levels in poorly controlled diabetes. Supplementation with ALA can help counter this nerve damage (Cardiovascular Diabetology, 2005, vol. 4, no. 5). Prediabetics can also use ALA to help keep diabetes at bay (Biochemical and Biophysical Research Communications, 2005, vol. 326, no. 1).

Beyond diabetes treatment, ALA also protects the liver from free radicals. This benefits people with chronic hepatitis, cirrhosis, and even liver damage caused by eating poisonous mushrooms—although in this case, ALA is administered intravenously (Free Radical Biology & Medicine, 1998, vol. 24, no. 6).

Several eye diseases, such as cataracts and glaucoma, are worsened by free radical presence. Shoring up the antioxidant defense system with ALA supplementation may improve or prevent cataracts and glaucoma (Alternative Medicine Review, 2001, vol. 6, no. 2).

Side effects
Very few problems are reported with this supplement; mild stomach upset or allergic skin rash occur rarely. ALA can lower blood sugar levels, so diabetics should monitor levels carefully and consult a doctor about adjusting diabetes medications while taking this supplement.

How to take it
For diabetics, research shows 600 mg of ALA per day to be beneficial. To treat diabetic neuropathy, aim for 800–1,200 mg per day. For healthy people taking ALA as a general antioxidant, 50–100 mg daily is sufficient. Although ALA is found in many foods—including liver, spinach, and broccoli—amounts don’t approach those found in nutritional supplements.

Cost
Prices vary depending on which form of ALA you choose. Traditionally, ALA supplements comprise a 50/50 mixture of R-lipoic acid and S-lipoic acid. Several manufacturers now sell pure R-lipoic acid, which is the only form naturally found in humans, plants, and animals. Reaching the 600 mg daily dose will cost about $37 a month with the natural R-lipoic form, versus $15 or more with the traditional mixture.

Oregon-based freelancer Victoria Dolby Toews, MPH, is the author of User’s Guide to Sexual Satisfaction (Basic Health, 2003) and User’s Guide to Glucosamine and Chondroitin (Basic Health, 2002).