A new study was just made available in draft form that examined blood, urine and skeletal tissues of 12 men with average age of 75 before and after supplementation with NR for 3 weeks.
The results were actually quite dissapointing overall, with none of the changes in cardiovascular performance, muscle strength, blood flow, blood lipids, or glucose metabolism that have been shown in mice, although a longer supplementation period might show improvement.
One area that did show improvement was significantly decreased levels of inflammatory cytokines in the blood, in particular interleukins IL-6 IL-5 , and IL-2, and tumor necrosis factor-alpha (TNF-a).
- NAD+ in the blood increased > 2x.
- NMN in the blood increased 1.4x
- NR in the blood was detected, but levels unchanged.
Where else did the 1,000 mg a day of NR go?
- NR in the urine increased
- NAM in the urine increased 2.5-fold
- MeNAM in the urine increased 5-fold
So, 1,000 mg of NR raises NMN and NAD+ in the bloodstream. NR is not raised in the blood, but any that does not make it to NAD+ or NMN is excreted in urine as NR, NAM and MeNAM.
Is the (unchanged) levels of NR in the blood responsible for the reduced inflammation, or is it the 2x greater levels of NAD+ that provide the benefit?
Looking at this, It’s hard to imagine swallowing NR capsules to raise NAD+ levels in blood along with all the MeNam (bad) makes sense compared to getting NAD+ direct to the blood.
I’ll post a link to an article on this I will finish this weekend
Nicotinamide riboside augments the human skeletal muscle NAD+ metabolome and induces transcriptomic and anti-inflammatory signatures in aged subjects
https://www.biorxiv.org/content/biorxiv ... RCAh1lBU3U
Still the NR doubled the presence of NAD+ and appeared to have an anti-inflammatory effect.
I suppose before we'd stop using NR entirely we'd want to see if there are functions or synchronicity that come with taking it with NMN and NAD+.
If not. I'd lean toward my mainstay of NMN + Resveratrol for the long term and NAD+ for more immediate results.