Stefan, I think we still need CR as control group in studies as it is not same as for usage, but to understand a certain mechanism. So I would add always CR AND nicotinic acid / nicotinic acid riboside (not Nam since already proven to be less potent than NA and shut sirt) : http://www.ncbi.nlm....les/PMC3616313/
in this study,
they explained the reason why they used NR instead of NA, and I let you take your own conclusion:
"The administration of NAD+ precursors, mostly in the form of nicotinic acid (NA), has long been known to promote beneficial effects on blood lipid and cholesterol profiles and even to induce short-term improvement of type 2 diabetes (Karpe and Frayn, 2004). Unfortunately, NA treatment often leads to severe flushing, resulting in poor patient compliance (Bogan and Brenner, 2008). These side effects are mediated by the binding of NA to the GPR109A receptor (Benyo et al., 2005). We hence became interested in the possible therapeutic use of alternative NAD+ precursors that do not activate GPR109A."
So purely, they admit NR wouldnt be superior to NA but since the later can induce flush then they moved for ONLY NR
they are maybe not aware that :
- the flush effect disappear after regular use and can be none if started at low dose
- activate GPR109A is a beneficial anti inflammatory pathway
- there is some form of niacin that are flush free http://www.iherb.com...-Capsules/37900 (extended release niacin, do not confuse with slow release preparation).
So they just not used nicotinic acid (niacin) as control. Fine, it was probably one of those sponsored chromadex studies ?
However since its not that black they found interesting things such as:
We also tested whether the increase in NAD+ would be concomitant to changes in other NAD+ metabolites. Strikingly, NADH and nicotinamide (NAM) levels were largely diminished in muscles from NR-fed mice
that mean modulate positively the NAD/NADH ratio and then probably turn off some nAD+ ase consuming enzyme as some speculated here. This is an interesting part.
So bad they didnt monitored that into other tissue but only in an NR specific tissue (muscle). However they stated that unfortunately: The image reveals that PGC-1a is not detectable by current immunoprecipitation protocols in total white adipose and brain lysates in conditions at which it is detectable in muscle, heart BAT or liver. (that mean that NR was kind of ineffective for others tissue).
And as we can see indeed for instance: in brain NR decreased a bit the sirtuins activity but increased it in the muscles. Thats why again we should see NA as control and should never rely on NR to completely help as an NAD+ boosting. We need stronger approach than just precursor, and should consider NA even if less marketed (as pushed by chromadex) and less expensive (so less sexy ?). Furthermore, NR is probably also a methyl consumer, so even if no flush, one would have to take B6, B9 and B12 with it is the case for all B3s
EDIT: what was true for niacin in the 1980s study regarding slow release niacin can be true for NR, so caution would be there too about supplementation with it more than twice a day. Again further studies are needed
Edited by Tom Andre F. (ex shinobi), 07 July 2016 - 04:32 PM.