One of the serious side effects for approximately one third of diabetes sufferers is a painful condition known as diabetic neuropathy. The symptoms are due to damaged nerves, particularly in the lower extremities, which can eventually lead to amputation. The nerve damage is thought to be due to the action of free radicals, and it occurs because of poorly controlled blood sugar level over a long period of time.

A recognized treatment for this condition in Germany since the late 1960s is supplementation with ALA. The compound is thought to combat diabetic neuropathy in several different ways:

• As an antioxidant it is able to neutralize free radicals before they cause oxidative damage, and there is also some evidence that alpha lipoic acid can help repair damaged tissue.
• Type II (adult onset) diabetes is characterized by high blood sugar levels that are the result of resistance to the action of insulin, rather than a lack of insulin. As alpha lipoic acid is actually produced within our bodies in order to assist with normal glucose metabolism, it seems reasonable that the compound may be able to provide additional benefits to diabetics. Indeed, several clinical trials have shown that, when taken in relatively high doses, ALA can improve glucose metabolism (that is, lower blood sugar) in diabetics by increasing insulin sensitivity.
• ALA is thought to be able to improve blood flow in the tiny blood vessels that supply nerves.

Diabetics have a higher than normal risk of vascular disease because of changes to the inner lining of blood vessels (endothelium). Improved endothelial function has been correlated with ALA supplementation in several small clinical trials involving diabetic subjects. It is thought that alpha lipoic acid achieves this benefit through a gene-regulatory mechanism which prevents the occurrence of detrimental endothelial cell activity.

Diabetics are also prone to kidney disease due to oxidative stress. A German study showed that diabetic patients with kidney disease who were supplemented with alpha lipoic acid had a slower progression in their illness than non-treated patients over a period of eighteen months.

Based on the available evidence, it seems highly likely that the health of many diabetics may be enhanced by supplementation with alpha lipoic acid.