- Oxidized nicotinamide adenine dinucleotide (NAD+) is an essential resource for the optimal function of the mitochondria
- Supplementing mice with nicotinamide riboside (NR), a precursor of NAD+, prevented muscle degeneration and enhanced muscle function in the treated animals
- NR also delayed the aging of stem cells in mice, resulting in an increase in lifespan
Actions to Consider
- Increasing your NAD+ levels could be beneficial for your lifespan and healthspan
- Although more studies are needed to confirm the effectiveness of NR in promoting longevity in humans, supplementing with the nutrient could be beneficial nevertheless (NR is a form of vitamin B3, after all)
- How much NR should you take to boost your NAD+ levels effectively? A study reported that long-term (12 weeks) supplementation with up to 1000 mg of NR per day is safe and well-tolerated in adults. NR supplementation effectively elevated NAD+ levels in all subjects of the study.
Stem Cells and Aging
Stem cells (SCs) are non-differentiated cells that can turn into any other type of cells, depending on the needs of your body at any given time. Regeneration and homeostasis are strongly linked to stem cell function.
Aging is naturally accompanied by a decline in SC function referred to as stem cell senescence. The result is a decrease in regeneration capacity and impaired tissue homeostasis.
A major reason behind SC senescence is a decrease in mitochondrial function.
Then, could stem cell aging be reversed by improving the function of local mitochondria?
What is this study about?
Today we’re looking into a study from 2016, in which the researchers analyzed if increasing local NAD+ levels could improve mitochondrial function and thus rejuvenate stem cells. In theory, this could enhance regeneration and lifespan in treated animals.
NAD+ for healthier muscle and longer life
Six weeks of supplementation with NR was enough to prevent muscle stem cell aging in mice and significantly improve muscle function. Specifically, NR-treated animals were able to run more and farther. Also, their grip strength was higher compared to that of non-treated mice.
What about NAD+ and lifespan?
Increasing NAD+ levels through NR supplementation also led to a minor increase in the lifespan of the treated animals. Although this effect wasn’t significant, the scientists noted that this could be explained by the fact that the NR treatment had been started in a late stage of the animals’ life. In theory, an earlier start of NR supplementation could yield better results in terms of increased longevity.
Although the lifespan-promoting effect of NR supplementation isn’t significant, its ability to improve muscle function and regeneration is a valuable feat in itself. Additionally, NAD+ seems to enhance the number and function of neural and melanocyte stem cells.
At the moment, there are no clinical studies on the effects of NR supplementation or NAD+ levels on longevity in humans, but that may change in the future.
Link to study: https://science.sciencemag.org/content/352/6292/1436