This is great news if you are a mouse!
Here’s the summary of the paper:
NAD+ repletion improves mitochondrial and stem cell function and enhances life span in mice, by
Hongbo Zhang, Dongryeol Ryu, Yibo Wu, Karim Gariani, Xu Wang, Peiling Luan, Davide D’Amico, Eduardo R. Ropelle, Matthias P. Lutolf, Ruedi Aebersold, Kristina Schoonjans, Keir J. Menzies, Johan Auwerx, (here, if you subscribe to Science.)
The oxidized form of cellular nicotinamide adenine dinucleotide (NAD+) is critical for mitochondrial function, and its supplementation can lead to increased longevity. Zhang et al. found that feeding the NAD+ precursor nicotinamide riboside (NR) to aging mice protected them from muscle degeneration… NR treatment enhanced muscle function and also protected mice from the loss of muscle stem cells. The treatment was similarly protective of neural and melanocyte stem cells, which may have contributed to the extended life span of the NR-treated animals.
Writing in Science, Leonard Guarente notes:
NAD was discovered over a century ago, and its role in cells as a redox conduit in metabolism was subsequently established. More recently, its oxidized form, NAD+, resurfaced as a key molecule in aging in organisms ranging from yeast to mammals by the finding that the antiaging proteins, sirtuins, are NAD+-dependent deacylases. These proteins play a key role in mitochondrial function. Indeed, aging is also associated with loss of sirtuin and mitochondrial function.
As to whether NAD+ replenishment can improve health maintenance in humans, it has been reported that cellular NAD+ amounts decline during human aging (11). Also, the strict conservation in the relevant pathways of NAD+ synthesis, sirtuins, and PARPs suggests that NAD+ replenishment may also provide health benefits in people. Still, it will be important to test in humans whether dietary supplementation with NAD+ precursors will raise cellular NAD+ concentrations sufficiently to compensate for the loss due to aging. If so, it will also be necessary to test, in rigorously controlled trials, whether raising NAD+ concentrations improves health parameters, such as blood glucose and lipid profile, as well as inflammation. More expanded trials could measure effects on bone density, endothelial cell function, muscle mass, or even cognition. If NAD+ precursors can positively affect health parameters, it is reasonable to anticipate their place at the table alongside more traditional pharmaceutical drugs in the treatment of diseases.
But before you do that you may want to check out some of the writing that comes up from the Skeptical Search Engine.