Is the NR (nicotinamide riboside)
supplement possible the long-awaited youth pill? Have we finally found a pathway to not just
longevity but longevity without age related diseases?
The current research focus has not been just
on NR, but what NR converts to, which is NAD, a coenzyme called nicotinamide adenine dinucleotide, which is essential to
life. Researchers are trying to find out if they boost NAD levels can this
reverse or slow aging or impact age related diseases. They have been encouraged
by the positive results, in multiple trials of elevated NAD levels, in cell
culture and animal research, as well as some small sampled human studies.
It should be mentioned that that
scientists have also been studying NMN
nicotinamide mononucleotide, another precursor to NAD, but this supplement is
not as readily available to the public so emphasis will be on NR.
So, what is NAD and why is it
so important?
NAD is
found in every cell throughout the human body, and in the cells of all living
things. NAD performs many functions that help maintain healthy cells, and it
plays a key role in DNA repair. Without this tiny coenzyme, life would not
exist. { 1 }
NAD is essential for energy
production in your body’s cells. It works with certain enzymes to release cell
energy via the mitochondria (commonly known as the powerhouse of cells). NAD is
also a helper molecule for certain proteins that regulate a broad range of
biological processes, and it plays an important role in cell signaling and
repair of DNA damage caused by free radicals and various environmental factors.
While we are
born with ample level of NAD, levels naturally decline with age. This is a twofold decline, because the body
produces less NAD as we age, and because we use more of the NAD we do have, as
our aging bodies experience more damage or stress.
Low levels of NAD, have been
linked to aging and chronic illnesses, such as heart disease, diabetes,
Alzheimer’s disease and retinol degeneration. {2}
When talking about
longevity, there is often mention of the sirtuins, proteins that are activated
by NAD. The sirtuins can actually repair DNA, or lengthen telomeres or decrease
inflammation, but when NAD level declines so does sirtuin activities.
Is NR, a NAD boosting supplement?
NR, nicotinamide riboside is an alternate form of vitamin
B3, niacin, and is a precursor to NAD.
The body is able to convert NR into NAD, and reportedly these
supplements can increase the NAD levels in the body.
To prove this, in 2016, Chroma Dex,
a company that produces the NR supplement, Niagen, sponsored the first small
published study conducted with humans. The result showed that NR was bioavailable
in supplement form and did increased the NAD levels in the blood by 40% to 90%
with dosages from 100mg to 1000mg in 12 healthy adults. {3}
Similarly, Elysium Health tested Basis, another
NR supplement that is combined with a polyphenol found in blueberries called
pterostilbene. Using a larger sampling
Elysium, administered basis to 80 adults between the age of 60 to 80, for an
8week period. Their results also showed 40% to 90% increase in NAD levels in
the blood. 4}
These two trials and others (with no ties to
these companies) have shown that NR can increase the levels of NAD in
the body but does this translate into an increased life and health span in humans.
Prior to these trials, a study published in the
journal Cell, found that injections of another precursor (not NR) rejuvenated
mitochondria in old mice, while further studies found that NR could improve
muscle and stem cell function and extend their life span, as well as improve
cognition in mice with Alzheimer. While
these finding are noteworthy, they are animal studies and so far, no clinicals
trials with humans have shown such benefit,
Something to consider
As we age the number of senescent cells, cells
that no longer divide, increase. These
cells are not just dormant, they release different factors and one is CD38.
CD38 lowers the level of NAD. The “… accumulation
of senescent cells may itself be a root cause of decreased NAD. “
One paper suggested there is a tradeoff that the
lower the NAD levels, the lower the senescent
cells’ “secrete proinflammatory factors.”
And that these cells should be eliminated before trying to increase NAD levels
with supplements. The author went further
and suggested to bypass raising NAD levels and focus on ridding the body of
senescent cells. {5}
There are currently two way to
rid the body of senescent cells either by fasting or taking a molecule such
as apigenin.
Beyond NR and onto NRH
NRH is a
reduced form of NR because there is evidence that NR is rapidly degraded by the
liver and in the blood. Testing has found that NRH is more stable and had a
more potent effect on NAD levels in the liver, and more importantly, unlike NR,
it was not metabolized
into nicotinamide. But like NR, it converts into NAD and can increase NAD
level, but more of the NRH is bioavailable. {6}
As you can see with
this new direction and more refinement, time and a large-scale trial is need to
determine if there are any long-term adverse effects with any or all NAD precursor
or increasing NAD levels. Or if elevating NAD levels would be more beneficial
in specific area, as shown in one trial where it significantly reduced
inflammation in muscle cells.
With 47 NR trials in
the pipeline, more answers and questions will be raised, and it might be worth
waiting for this information before trying a supplement.