The lipoic acid produced in the body is closely bound to certain proteins and is essential to work in harmony with the B complex vitamins for the release of energy from food. No symptoms have ever been attributed to a deficiency of this type of lipoic acid, suggesting that the body is always able to manufacture a sufficient supply for this purpose. Research has focussed, however, on the possible benefits of high dose supplementation with what is known as "free lipoic acid", which does not bind with proteins in the body.



Lipoic acid functions as an anti-oxidant, assisting in the destruction of the free radicals which may damage cell DNA and membranes. However, lipoic acid is found in tiny quantities when compared with other anti-oxidants such as vitamins C and E, and the enzyme, glutathione. Moreover, any increase in lipoic acid activity obtained through supplementation is likely to be short lived. The real anti-oxidant importance of lipoic acid, however, lies in its capacity to recharge and renew these other anti-oxidants, consequently enhancing their potency.

Lipoic acid has also been shown to stimulate the production of glutathione in the body, a particularly important consideration in the case of the elderly who commonly have difficulty synthesising this enzyme and are consequently more vulnerable to the free radical attack which may damage cells and ultimately contribute to degenerative disease.

Research has suggested that high doses of lipoic acid may assist individuals with type 2 (non-insulin dependent) diabetes by improving glucose regulation and reducing the resistance to insulin which is characteristic of this form of the disease. Doses of 600 mg per day and more have been shown to enhance the action of insulin in type 2 diabetic individuals by as much as 25% after four weeks. It is much less clear, however, whether such courses of treatment will maintain similar benefits in the longer term.

There are also indications that lipoic acid may be effective in the alleviation of the pain and weakness commonly suffered by diabetic individuals as a result of peripheral nerve damage, particularly in the lower legs and feet. Close control of blood glucose levels has been found to be the best means of preventing this diabetic neuropathy, and although research suggests intravenous supplementation to be the most effective, both oral and intravenous supplements of lipoic acid are approved as treatments in Germany.

It has been suggested that lipoic acid's role in improving circulation and the general health of the vascular system may be responsible for its mitigation of the effects of diabetic neuropathy, but orthodox opinion is that more long term studies are required to establish this link. Supplementation in the case of diabetics should in any case only be undertaken under medical supervision.

But the possible benefits of lipoic acid don't end here. Lipoic acid is a valuable tonic for the liver, assisting its regeneration and recovery from hepatitis and toxic assaults such as drug, alcohol or fungal poisoning. A number of animal experiments have also appeared to show that supplements may restrict the activity of an enzyme associated with the progression of multiple sclerosis. As always, however, in the cautious world of orthodox medicine, it is argued that more long-term studies are needed before any definitive statements are made.

Likewise, although there have been some encouraging indications that lipoic acid may have a positive effect in slowing down memory loss, age-related cognitive decline and dementias, including Alzheimer's disease, larger long-term trials are needed before any definitive statements can be expected from the scientific community.

As always with supplementation, however, it is a question of weighing large potential benefits against the risks. As indicated above, lipoic acid is approved as a medical treatment in Germany and is freely available as a food supplement in the US and elsewhere. The few adverse reactions to oral supplements which have been recorded have been confined to relatively minor skin irritations and gastric upsets.

Moreover, good food sources are limited to the unpopular offal and dark green leafy vegetables, and even the best of these will provide only a tiny fraction of the bio-available lipoic acid that can be obtained from supplements. Indeed, because of the difficulty in absorbing lipoic acid in the presence of food, this is one of the very few cases where it's recommended that supplements should be taken on an empty stomach

It needs to be stressed again, however, that because of its potential effects on blood sugar regulation diabetics should not embark on a course of supplements without first seeking medical advice.