Have a look at  https://hms.harvard.edu/news/rewinding-clock article regarding NAD+. How they discovered to reverse ageing in cells.  For the full article click on the link above, the abbreviated version below: 'Harvard translate for dummies'.

Harvard translate for dummies - Blood vessels supply oxygen and nutrients to organs and tissues.

As we get older, our tiniest blood vessels wither and die, resulting in reduced blood flow, in turn reducing oxygen and nutrients received by the organs, muscles and tissue. The reduced oxygenation and nutrients received by the muscles can result in various disorders such as heart disease, neurologic conditions (for example Alzheimers, dementia), muscle loss, slow or diminished healing of wounds, frailty etc.

There are three players involved in the drama

• endothelial cells lining the blood vessels,
• the protein Siruin1 (or SIRT1A) and
• NAD+

NAD+ boost SIRT1A. The protein SIRT1A boosts the interaction between the endothelial cells, blood vessels and muscles The boosts resulting in increased blood flow to muscles i.e increased oxygen and nutrient supplies, working against the signs of ageing.

The whole process starts with NAD+. 

Experiments on mice (their age the equivalent of 70 in human years) who had received an NAD+ supplement showed increased blood flow to muscles, compared to their untreated mice counterparts.

Their ability to exercise was impressive, between 56-80% more than the untreated mice.  The NAD boosted mice ran 430 meters, compared to 240 meters of their untreated counterparts. (Grand Dad beating you in a marathon)

Harvard had its epiphany in 2019.  

Thirty years earlier, in 1989 Clinical psychologist Theo Verwey founded NAD therapy.  In 1989 Theo Verwey and Dr Ockie van Wyk started NAD IV.  In 1997 they developed the formula for the first stable form of oral NAD, knows as NAD+ Phyto.  Reversing the signs of ageing has been on the market for 30 years already in the form of NAD+ Phyto.

Why don’t you and your granddad/ grandma take the NAD+ Phyto supplement, see who will win the marathon!