Well, it depends. That's a first approximation when you don't have human blood levels in hand, but now that we have data in both species, it does look like it takes more, rather than less resveratrol to attain equivalent plasma levels in humans. I think the factor is closer to 4 than 6 though. There's also the question of the size of the plasma compartment relative to remaining compartments in both species, and other technicalities, but Sirtris was dosing humans at 5 grams a day. They did find that they were getting decent results at 2.5 grams a day, so maybe it's not as bad as all that.No, Human Equivalent Dose = rat divided by 6.2, not multipliedI'm convinced I would have to take huge amounts to overcome the bioavailability issue (we require 6x the equivalent rat amount).
The standard scaling rule of human = 1/6 rat might have come about from looking at typical druglike molecules where oxidative metabolism (P450s) may be more important. Rodents are known to be more efficient oxidizers than humans. On the other hand, resveratrol doesn't get oxidized at all. Instead, it gets conjugated, and humans seem to conjugate the hell out of it. Perhaps we are more efficient conjugators than rats are, although I don't have any data on that.
Edited by niner, 22 February 2008 - 10:59 PM.