Lipoic Acid (or alpha-lipoic acid) is a substance that is made in the human body that primarily helps us create energy. It contains sulphur and as a result is yellow in colour. Extra quantities, in addition to what our bodies produce, can be consumed from certain foods, and as supplements. It is sometimes abbreviated as LA or ALA, which is confusing, as these are also terms for the two plant sources of essential fatty acids, namely linoleic acid and alpha-linolenic acid.
Lipoic acid in the body.
In most of the 10 trillion or so cells in our body are a number of small organelles called mitochondria. These are the power plants of our cells, that produce energy by metabolizing the breakdown products of the foods we eat. Lipoic acid is produced in the mitochondria. It's precursor, octanoic acid is normally attached to an enzyme, where it is converted into lipoic acid by addition of sulphur. Most naturally produced lipoic acid is attached to enzymes in the body, with very little floating about free in the blood. Lipoic acid in the blood is either derived from food, which is not a big source of lipoic acid, or from supplements.
Lipoic acid is soluble in both water and fat, and as such can get to most areas of our body quite easily. This is in contrast to most vitamins, which are either fat-soluble (Vitamins A, D, E and K) or water soluble (Vitamins B & C). It is also notable that lipoic acid can cross the blood-brain barrier. This gives it access to the brain and spinal cord. A fact that makes it potentially useful as a therapy for multiple sclerosis.
What does Lipoic acid do for us?
Lipoic acid is touted as a substance that can help us live longer by reducing the damage caused by oxidative stress that can lead to degenerative diseases. It is also thought to increase our energy levels. In addition lipoic acid has been used to improve symptoms in diabetes and multiple sclerosis, and with prevention of strokes.
Reduce risk of degenerative disease such as cancer.
Lipoic acid is an antioxidant that decreases oxidative damage to our cells. It is thought that by reducing the damage caused by oxidative stress the risk of chronic diseases such as cancer may be reduced. There is indeed some evidence that in combination with carnitine the damage seen in the mitochondria of older cells can be reduced1. Studies with lab rats have certainly suggested the possibility that lipoic acid could result in life extension. However the limited number of studies in humans have not had such marked effects.
Increase energy levels.
Lipoic acid is found in our mitochondria helping out at several steps of this energy production process. Although we produce lipoic acid ourselves, a recent study has found that additional mitochondria can be produced in cells if supplemental lipoic acid is taken2. There seems to be quite good evidence that for those with chronic diseases such as diabetes and MS, levels of fatigue can be reduced. For those with normal energy levels it is doubtful that they will increase their energy levels however.
Reduce symptoms of diabetes.
There is some evidence that lipoic acid can help our cells take up glucose, with one small trial showing a 50% increase in insulin stimulated glucose uptake after supplementation with 1000mg3. Lipoic acid also helps prevent the nerve related symptoms (neuropathies), that diabetics often suffer from. These are typically pain and loss of feeling in the lower legs. A large study of 1258 diabetic patients in Germany found significant improvements in symptoms, after supplementation with 600mg per day for 3 weeks. This suggests that the risk of serious complications of diabetes, such as leg amputation, could be reduced by lipoic acid supplementation4. In Germany the use of lipoic acid for treatment of these diabetic neuropathies is approved by the medical authorities.
Reduce symptoms of Multiple Sclerosis (MS).
While there are not yet any major long term clinical studies on the effect of lipoic acid supplementation on MS, there is evidence that it could work. One study showed that it reduced amounts of a protein called MMP-9, which can cause damage to the brain and spinal cord5. Another study on rats slowed the progression of a disease similar to MS. Many, but not all MS sufferers who have taken it, have experienced reduction in levels of fatigue. It is often taken with l-carnitine in this context, with typical supplemented amounts being: 400mg lipoic acid and 1000mg carnitine.
Studies have shown that lipoic acid can reduce blood pressure in diabetic patients6.
There are some other health conditions where lipoic acid may be helpful. Firstly eye degeneration due to cataracts or glaucoma. Secondly cognitive decline and dementia. If you know someone with these conditions, it may be worth investigating the possible benefits of lipoic acid supplementation.
Supplemental Lipoic Acid.
Lipoic acid is widely available in supplemental form. Most supplement companies classify it as either an anti-oxidant or energy booster. Its greatest benefit however is likely to be felt by those with conditions identified above.
There are two types of lipoic acid molecule, the"r" type and the "s" type. The "r" type is the one found naturally. Supplements may contain the "s" type. While this is not toxic it is at least half as effective as the "r" type. Another consideration is whether to get lipoic acid or purchase DHLA, the reduced form of lipoic acid. DHLA is sold by some companies, but our body is pretty effective at turning lipoic acid into DHLA, so it is probably not neccessary to get this form.
A by product of the production of supplemental lipoic acid called epilioic acid may be harmful. Some companies remove this while others do not. However, it is generally considered by most authorities that long term supplementation is likely to be safe7. Side effects that have been reported include smelly urine and nausea, however these side effects are not that common. Because lipoic acid is very similar in shape to the vitamin biotin, and therefore likely to compete with it in the body, some practitioners recommend that biotin supplements are taken along with lipoic acid.
Supplemental lipoic acid at amounts greater than 50mg, leads to significant increases in the lipoic acid levels in your blood. To maximise the effect, the lipoic acid should be consumed outside of mealtimes. The levels in your blood will peak within an hour after taking a supplement and will reduce quickly thereafter. It is typically marketed to be taken as amounts between 100-200mg. However, for those with conditions such as diabetes and MS amounts between 300-600mg would likely be more effective.
A brief look at the 3 supplement companies I deal with, has the following formulations:
- BioCare: Classified as providing extra energy - 200mg complexed with 300mg of carnitine.
- Nutri: Classified as an anti-oxidant and energy support - 300mg on its own.
- Solgar: Classified as an anti-oxidant - 60, 120 and 200mg on it own.
- Holland and Barrett: Classified as an anti-oxidant - 100mg.
Interestingly, the price charged by the the mass market company, Holland and Barrett, was quite a bit more than specialist practitioner companies such as Nutri and BioCare.
Which foods contain Lipoic Acid?
Lipoic acid can be found in organ meats, especially liver, as well as red meat and brewers yeast. There is also some to be found in green leafy vegetables8. However the amounts found in foods are many time less than the amounts found in most supplements, so it is probably not worth targeting particular foods if you want to increase the levels of lipoic in your body.
For people with diabetes or multiple sclerosis, it is certainly worth consideration. For people in good health perhaps the key question is can lipoic acid extend lifespan.
While there is some evidence that it can reduce oxidative stress and boost energy levels, it could also possibly reduce muscle mass9. There is no firm prroof that supplemental lipoic acid will extend lifespan, and I would advise any healthy person wanting to reach 100, to consider first if they could increase the range of vegetables that they eat, rather than purchase lipoic acid.
1) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2945683/ Evidence that lipoic acid in combination with carnitine decreases mitochondrial aging.
2) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2882509/ Evidence that lipoic acid can increase numbers of mitochondria and improve glucose tolerance. However it also decreased lean and fat mass.
3) http://www.ncbi.nlm.nih.gov/pubmed/7575750?dopt=Abstract Eividence for improvement in blood glucose handling.
4) http://www.ncbi.nlm.nih.gov/pubmed/14984445?dopt=Abstract Evidence of reduction in diabetic neuropathies.
5) http://www.ncbi.nlm.nih.gov/pubmed/15794388 Evidence of effect with Multiple Sclerosis.
6) http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2362.2009.02236.x/full Evidence of better arterial vasodilation using lipoic acid.
7) http://www.researchgate.net/publication/6888520_Long-term_safety_of_alpha-lipoic_acid_(ALA)_consumption_A_2-year_study Evidence that supplementation is probably safe.
8) http://lpi.oregonstate.edu/infocenter/othernuts/la/ Comprehensive information about lipoic acid.
9) http://www.ncbi.nlm.nih.gov/pubmed/20015518 Could lipoic acid cause lean mass loss?