carnitine?

[shona]

A popular doctor with a website sells a supplement for people over 50 who want more energy that has alpha lipoic acid and l-carnitine. It's very pricey so I decided to take my own individually. My questions are:
What is the difference between acetyl l-carnitine and l-carnitine?
Has anyone had any experience with carnitine?
I already take r-lipoic acid so I just need to add the carnitine. Thanks!

[BroMax]

I take 500mg of l-carnetine per day at the recommendation of my doctor. She says that type II diabetes (which I have) can cause a deficiency. There were a few benefits she claimed but the only one I can remember is that I'd be less likely to experience constipation--and she is right about that. I but it at an independent health food store in South Salem for about $36 per bottle. I think that's a two month supply but I could be wrong about that. Sorry I can't help with the differences in formulation.

[RNS]

I'm not sure on the actual physiologic differences in the two, but alcar is liked by many more people and is used as a quite effective nootropic/mood enhancer/energy sustainer. I'm guessing the acetyl group just ups absorbtion, but I'm not quite sure. If the product you're looking at only has alcar and r-ala then don't spend too much on it. Online bodybuilding and supplement retailers will have it for much cheaper, neither are too expensive.

[slowandsteady]

Couldn't get the whole study since it is in russian but here is the abstract. Seems to give an okay summary of the two.

Ukr Biokhim Zh. 2005 Jul-Aug;77(4):30-50.


[Vitamine-like substances L-carnitine and acetyl-L-carnitine: from biochemical studies to medicine]

[Article in Russian]

Kopelevich VM.
Recently reported data clarify our understanding of the molecular aspects of carnitine in medicine. Carnitine is a compound necessary for the transport of acyl-CoA across the inner mitochondrial membrane for their beta-oxidation. Only L-isomer of carnitine is biologically active. The D-isomer may actually compete with L-carnitine for absorption and transport, increasing the risk of carnitine deficiency. By interaction with CoA, carnitine is involved in the intermediary metabolism by modulating free CoA pools in the cell. Detoxification properties and anabolic, antiapoptotic and neuroprotective roles of carnitine is presented. Carnitine deficiency occurs as a primary genetic defect of carnitine transport and secondary to a variety of genetic and acquired disorders. The pathophysiological states associated with carnitine deficiency have been summarized. L-Carnitine is effective for the treatment of primary and secondary carnitine deficiencies. Acetyl-L-carnitine improves cognition in the brain, significantly reversed age-associated decline in mitochondrial membrane potential and improved ambulatory activity. The therapeutic effects of carnitine and acetylcarnitine are discussed.

In a number of studies I looked at, acetyl-L-carnitine was neuro protective in a number of different models of alzheimers, diabetic neuropathy, neuro toxicity(paclitaxel) and radiation. It also protected against oxidative stress. Most of the studies, and there are a lot, demonstrated these positive effects with acetyl-L-carnitine.

There was also a study done with cyclists, but I don't have a subscription to that journal so I can't get the whole study. But if you really care, you can always order it yourself. Here is the reference

White LJ, Robergs RA, Sibbitt WL Jr, Gasparovic CM, Petropoulos H, Brooks WM.
Accumulation of acetyl groups following cycling: a 1H-MR spectroscopy study.
Int J Sports Med. 2006 Feb;27(2):100-4.
PMID: 16475054 [PubMed - in process]

[Bockman]

l-carnatine is a medium-chain triglyceride which your body 'treats' or 'reacts to' as a long chain triglyceride.