A common nutrient sold as a dietary supplement may help ease the pain caused by diabetic neuropathy (search), according to two new studies.

An analysis of the studies shows that a 1,000 milligrams three times a day of acetyl-L-carnitine (search) was effective in relieving pain caused by nerve damage associated with the condition.

Diabetic neuropathy is a common long-term complication of diabetes and results in damage to nerve fibers, which can cause pain or a tingling sensation. People with this condition also suffer from a loss of sensory perception in the affected areas.

Acetyl-L-carnitine (ALC) is a naturally occurring chemical and is often sold as a dietary supplement.

Nutrient May Treat Diabetic Neuropathy

In the analysis, which appears in the January issue of Diabetes Care, researchers evaluated the results of two studies testing two doses of acetyl-L-carnitine -- 500 milligrams and 1,000 milligrams three times a day.

The two studies involved 1,257 people with diabetic neuropathy in the U.S., Canada, and Europe and lasted for one year.

The analysis shows that people treated with the 1,000-milligram dose of acetyl-L-carnitine showed significant improvement after both six months and one year of treatment. Those who experienced the greatest pain reduction after one year with the 1,000-milligram dose were those with type 2 diabetes, those who took their medications as directed, and those who had their diabetes less than optimally controlled (HgA1c (search) was greater than 8.5 percent).

In addition the degree of pain relief was greatest among those who had diabetes for the shortest time period. Those with the shortest duration of diabetes also showed improvements in nerve structure and perception of vibration.

Researchers say those results indicate that longer studies are needed to examine the full effect of acetyl-L-carnitine in the treatment of neuropathic pain. For example, starting the therapy at an earlier stage may delay progression or reduce severity of the condition.

By Jennifer Warner, reviewed by Brunilda Nazario, MD

SOURCE: Sima, A. Diabetes Care, January 2005; vol 28: pp 96-101.