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03.11.2010

Alpha-Lipoic acid has positive and negative effects on body composition

Alpha-lipoic acid is more suitable as a supplement for endurance athletes and people who want to lose weight than for strength athletes, according to an animal study done at China Agricultural University.

Most of the alpha-lipoic acid in our body has been made by our own cells. We only get a minimal amount from the food we eat. The best source is organ meat with a high metabolic rate, like kidneys, heart and liver. If you want to experiment with alpha-lipoic acid, you're better off taking supplements. A good supplement contains a few hundred milligrams of synthetic alpha-lipoic acid. To put this in perspective, when they isolated 30 mg of alpha-lipoic acid from meat the first time, the researchers needed ten tons of liver.

In the cells of the body, alpha-lipoic acid is involved in the conversion of nutrients – especially glucose – into energy. Research has also been done on alpha-lipoic acid for treating poisoning, radioactive radiation, and even cancer and HIV, but most research is directed at diabetes.

The Chinese study was aimed at finding out how alpha-lipoic acid works exactly, and in particular in older organisms. That's why the researchers used lab mice that were 24 months old. The geriatric mice were given drinking water containing 0.75 percent alpha-lipoic acid, for a month long.

If you convert the dose they used to human proportions, taking into account the fact that humans have slower metabolism, then this amounts to a few g per day. Supplements users take 600-1800 mg/day. The dose that the elderly mice got corresponds to what doctors use in experiments on people with cancer or HIV.

The supplements made the mice burn more calories. Their bodies slimmed down, but they also lost some lean body mass.

In the muscle cells, the supplement activated the glucose transporter GLUT4, a protein that removes glucose from the blood vessels, and PGC-1-alpha, a key molecule that induces cells to synthesize more mitochondria. This is what happened in the mice's muscle cells.

What's crucial to the way alpha-lipoic acid works is that it activates the enzyme AMPK. This enzyme is activated if cells have no fuel left, as it stimulates the muscle cells to generate energy. The downside of this is illustrated above: mTOR, p70S6K and 4E-BP1 become less active. These are signal molecules that stimulate the growth of muscle fibres.

The anti-anabolic effect of alpha-lipoic acid is not very big. If it is an issue at all at lower dosages, the effect is probably more than cancelled out by combining it with creatine. Strange but true: alpha-lipoic acid improves the muscle cells' creatine uptake. [Int J Sport Nutr Exerc Metab. 2003 Sep;13(3):294-302.]

"With beneficial metabolic actions, LA may be a promising supplement for treatment of obesity and/or insulin resistance in older patients", the researchers conclude.

Source:
Metabolism. 2010 Jul; 59(7): 967-76.