Interesting, but seems to be self-contradicting at first glance.
Since ALA is 50% R-ALA by weight, then wouldn't a person who takes ALA also be taking R-ALA ??
Advertisements by vitamin distributors containing articles that recommend taking ALA therefore also advocate taking R-ALA, since ALA is 50% by weight of R-ALA.
If R-ALA, the naturally-occuring form of lipoic acid, is "bad", then it would seem that those advertisers ought be promoting only the non-naturally occurring S-form. Are there any studies on the S-ALA ??
I have seen half a dozen studies showing R-ALA is superior to S-ALA.
Seems like there is yet another controversy among people in these businesses.