Funny, our two posts essentially contradict each other. I concluded that the study was likely done with people who were only taking d-alpha b/c that is what you normally get when you buy a bottle of vit E at the drugstore. The mixed tocopherols are much less common, so it is unlikely that that more than a small minority were supplementing with the mixed tocopherols.
More recent research has demonstrated that if you supplement only with Alpha, you are displacing Gamma or other forms, which are just as important. Supplementing with high doses of d-Alpha only would presumably cause an imbalance which may limit the benefits.
I'm not trying to start a debate, rather I thought your comment was interesting b/c we are all so mixed up on these matters.
I'm especially interested in your statement that Mixed Tocopherols are not stable. Even though I don't supplement with E other than in a multi, I intend to look into your statement out of sheer curiosity.
It is amazing what many in the supp. industry will try to pawn off on us. For instance, promising research on Lipoic Acid led the marketers to begin selling Alpha-Lipoic Acid. Well, the problem was that the studies were done with R-Lipoic Acid. I will spare everybody the technical difference, but suffice to say it is not necessarily the same thing. Why did they sell ALA instead of RLA? Because RLA was not stable and it was much more costly to produce. Only recently have they begun to sell the RLA as more intelligent enthusiests began to demand it and manufacturing costs have come down. The stability issue is still there, so one manuafacturer started bonding potassium to the molecule which stabilizes it. I have no idea whether this effects efficacy (they of course claim it doesn't).
I am a huge Adele Davis fan. I tend to listen to people if they have at least a Masters degree in biochemistry, which she had. She compiled many studies which were conducted over a 30 to 40 year span which proved that d-alpha was the best and that the mixed tocohperols were not to be used because of their instability. She also noted that natural vitamins were to be preferred.
There are 8 isomers of vitamin E including tocotrianols.