cockdezl said:
I saw alot of statements in this thread, but no research to support a supposed deleterious effect of S-ALA.
Until I can see some harder evidence than this, I will continue to save money and purchase the 50/50 racemate.
At the same time, insulin levels in animals that were supplemented with R(+)-Lipoic Acid were pushed down by 17%, proving that the vicious circle of insulin resistance was being put into reverse. By contrast, S(-) lipoic acid actually caused insulin levels to soar 15% higher.
...Looking down at these animals' cells, scientists could see what had happened. The amount of GLUT-4, the muscles' main glucose transporter, was actually reduced by 19% by S(-) lipoic acid supplementation!
Streeper RS, Henriksen EJ, Jacob S, Hokama JY, Fogt DL, Tritschler HJ. Differential effects of lipoic acid stereoisomers on glucose metabolism in insulin-resistant skeletal muscle. Am J Physiol. 1997 Jul;273(1 Pt 1):E185-91.
S(-)-lipoic acid actually interferes with the cell's ability to mobilize GLUTs.
Estrada DE, Ewart HS, Tsakiridis T, Volchuk A, Ramlal T, Tritschler H, Klip A. Stimulation of glucose uptake by the natural coenzyme alpha-lipoic acid/thioctic acid: participation of elements of the insulin signaling pathway. Diabetes. 1996 Dec;45(12):1798-804.
“The S(-)-enantiomer … part of the racemate, which is present as about a 50% impurity [our emphasis], needs to be eliminated."
Zimmer G, Mainka L, Ulrich H. ATP synthesis and ATPase activities in heart mitoplasts under influence of R(+)- and S(-)-enantiomers of lipoic acid. Methods Enzymol. 1995;251:332-40.
“We’re finding – and others are, too – that the R(+)-form – the natural form – is much more powerful than the racemic mixture ... Hopefully ... companies are going to be producing on more of a clinical scale the R(+)-form of lipoic acid, because we’re finding very significant effects using this, as opposed to the racemic mixture.”
Hagen TM. Mitochondrial decay in aging: reversal with dietary supplementation. Presentation to the 29th Annual ISOM Conference. April 6-9, 2000;Vancouver, BC.
“Lipoic acid sold in a health food store is a synthetic mixture, a racemic mixture. And R[+]- is the natural form and S[-]- is an unnatural one ... And in our hands R[+]-works and S[-]- doesn’t.”
Haramaki N, Stewart DB, Aggarwal S, Ikeda H, Reznick AZ, Packer L. Networking antioxidants in the isolated rat heart are selectively depleted by ischemia-reperfusion. Free Radic Biol Med. 1998 Aug;25(3):329-39.