Here I'll point out a recent study on nicotinamide riboside supplementation in mice. This is a way to increase levels of nicotinamide adenine dinucleotide (NAD), an important player in many aspects of cellular metabolism, particularly mitochondrial function and everything associated with it. Mitochondria are known to be important in aging, either through a decline in their primary function of producing energy stores to power cellular activities, or in the damage they suffer that leads to malfunctioning forms of this cellular component.
Thus far, based on work from the past few years, inducing raised levels of the charged form of NAD, NAD+, in mice appears to be a way to trigger some of the same housekeeping and repair mechanisms as are affected by hormesis and heat shock factors in response to various forms of cellular stress, which is to say that it can modestly slow aging and improve health. Everything is interconnected in cellular biochemistry, so it isn't all at unusual for there to be a dozen or more ways to manipulate any one set of mechanisms. Here the focus is on improved stem cell activity, which is becoming a very common theme in research on aging.
As mice age, the regenerative capacity of certain organs (such as the liver and kidneys) and muscles (including the heart) diminishes. Their ability to repair them following an injury is also affected. This leads to many of the disorders typical of aging. Through the use of several markers, researchers were able to identify the molecular chain that regulates how mitochondria - the "powerhouse" of the cell - function and how they change with age. The role that mitochondria play in metabolism has already been amply demonstrated, "but we were able to show for the first time that their ability to function properly was important for stem cells." Under normal conditions, these stem cells, reacting to signals sent by the body, regenerate damaged organs by producing new specific cells. At least in young bodies. "We demonstrated that fatigue in stem cells was one of the main causes of poor regeneration or even degeneration in certain tissues or organs."
This is why the researchers wanted to "revitalize" stem cells in the muscles of elderly mice. And they did so by precisely targeting the molecules that help the mitochondria to function properly. "We gave nicotinamide riboside to 2-year-old mice, which is an advanced age for them," said the researcher. "This substance, which is close to vitamin B3, is a precursor of NAD+, a molecule that plays a key role in mitochondrial activity. And our results are extremely promising: muscular regeneration is much better in mice that received NR, and they lived longer than the mice that didn't get it." Parallel studies have revealed a comparable effect on stem cells of the brain and skin. So far, no negative side effects have been observed following the use of NR, even at high doses. But caution remains the byword when it comes to this elixir of youth: it appears to boost the functioning of all cells, which could include pathological ones. Further in-depth studies are required.
I'll note that the publicity department that formed up this release should be ashamed of themselves for the title, which is a enormous exaggeration. It is bad enough that the popular press consistently misstates the results of research into aging, when so much of that research produces only small effects, without the allegedly more responsible parties also doing so. Not all longevity science is equal, but when everyone claims to have stopped aspects of aging - when no such thing actually happened - it becomes that much harder for laypeople to gain an appreciation for what is more or less useful in the field.