What are NMN supplements and why are they important for longevity?

NMN supplements are being touted as miracle cures that can reverse the aging process, but what is NMN and do these claims stack up?

Modern medicine has done amazing things. During the 20th century, life expectancy for men rose from 48 to 74 years and from 51 to 80 years for women. People are living longer, but a longer life doesn’t mean better health. Healthcare systems have become extremely good at keeping us alive, but in many cases that just means people living on with long term conditions which are a drain on health services and their own quality of life.

Many people are turning to health supplements and one of the most popular includes nicotinamide mononucleotide (NMN). The market for longevity supplements is growing. These products promise to extend life, combat diseases and make us feel younger for longer. However, marketing teams tend to make all sorts of claims. To work out whether these claims can be believed, we need to understand what NMN is and how it works.

What is NMN?

NMN is a precursor of another important molecule, called nicotinamide adenine dinucleotide, more commonly known as NAD+. Our bodies use NAD+ for a number of purposes – the most important of which is to act as fuel for molecules that repair damage to DNA, provide energy and improve immune systems. It is critical in maintaining high metabolisms and generally keeps important functions in our body working well.

As we age, levels of NAD+ tend to decline which in turn means all those molecules that rely on NAD+ for their fuel start to become less effective. By the time we reach middle age, the amount of NAD+ in our bodies will be roughly half the levels they were in our youth. The inevitable result is that our bodies become less effective at converting energy into fuel, combating disease, repairing DNA and all the other things which are needed to keep you healthy.

Scientists have linked declines in NAD+ to various age-related health problems such as heart disease, cancer, obesity and even neurological disorders. Each of these, so the theory goes, can be improved if the amount of NAD+ in your body increases.

The science behind NMN

The question is how can we get that NAD+ into the body? That’s where NMN comes in. Simply adding NAD+ into the body through supplementation has not been shown to boost NAD+ levels. Instead, supplements work by giving the body the ingredients it needs to make NAD+ itself. Supplements rely on a number of so-called precursors including, Nicotinamide Riboside (NR), Nicotinic Acid (NA), Nicotinamide (Nam), Tryptophan (Trp) and of course Nicotinamide Mononucleotide (NMN).

Many forms of supplements rely on NR. This is a form of vitamin B3 which is thought to be one of the most efficient precursors of NAD+ to exist. This means it produces the highest amount of NAD+ for the least amount of energy.

NMN is a relatively new introduction into the market, and some insist it could be even more effective than NR. It is an intermediary molecule which sits between NR and NAD+, in that NR has to become NMN before it can be turned into NAD+. This is partly why some people believe it could be a more effective precursor than NMN although the two have not been trialled head-to-head. Studies also suggest NMN can have a dramatic impact on longevity. For example, one study found it could extend the life expectancy of mice by more than 20%.

Benefits of NMN supplements to health and longevity

Exactly what those benefits might be is a process of some scientific discovery. New studies appear by the week linking NMN to fresh benefits including:

Heart function: The human heart keeps going at a steady pace throughout your life. It doesn’t rest or slow down. It consumes a huge amount of energy for which it is dependent on NMN. A study from the University of Washington discovered that treating older mice with NMN and SS-31 could improve heart function. When taken together, they worked to recapitulate the function and metabolisms of younger hearts.
Obesity: NMN has also been linked to lower levels of obesity. One study found that a three week NMN treatment in mice resulted in reduced fat mass, liver and plasma triglyceride levels and improved glucose tolerance. NMN has been seen as having a calorie restrictive effect by moving cells from a state of growth into a state of repair. However, obesity is a complex issue and will depend on a host of other factors including environment, lifestyle and diet.
Repairing DNA: NMN produces NAD+ which can activate sirtuins which play a crucial role in maintaining DNA integrity. When cells divide, the DNA at the end, or telomeres, of chromosomes grows a little bit shorter. At some point, this will begin to damage genes. Sirtuins slow this process down by stabilising the telomeres. A number study from Baylor College of Medicine found that giving activated sirtuins could stabilise telomeres, reduced DNA damage and contributed to the reduction of liver disease. By raising NAD+ and activating sirtuins, NMN supplements can boost the body’s ability to continually refresh DNA and slow the rate of damage.
Improved muscle endurance: NMN supplements are also being looked at to improve general fitness and conditioning levels. NAD+ metabolizes glucose and fatty acids which muscles use to maintain their structure and remain strong. As we age, our muscles decline in size and strength. By keeping NAD+ levels high through daily supplements with NMN, age related muscle decline may slow improving fitness both in the short and long term.
Improved mitochondria function: People cannot live without mitochondria, and it cannot exist without NAD+. Mitochondria are powerhouses for the cell providing them with energy. They are crucial for metabolisms and convert molecules from the food we eat into energy for our cells. Lower metabolisms will see this process become less efficient and will, in turn, lead to issues such as obesity. NAD+ enables mitochondria to metabolise.
Improved brain function: There is considerable evidence that NMN improves brain function. Scientists from the University of Oklahoma Health Sciences Center discovered that administering the NMN molecule in mice improves blood vessel dilation which improves the flow of blood to the brain and helps it to function more effectively. This aids a process called neurovascular coupling in which the blood flow to the brain rises when neural activity increases. In the short term, this could leave you feeling sharper and more alert while in the longer term it may play a role in slowing cognitive decline.
Eye function: Lower levels of NAD+ have been shown to contribute to neurodegeneration in the eye and vision loss. By replenishing NAD+, it should be possible to reduce this decline and improve vision. Studies have also shown that treatment with NMN can protect eye cells which preserves eye cell viability and can address conditions such as dry eyes and improve tear production.
Protects against diabetes: Having low insulin sensitivity levels is a precursor to type 2 diabetes. The body becomes less reactive to insulin levels in the blood stream which can increase the risks of weight gain and ultimately diabetes. Research suggests that a long-term administration of NMN can increase the body’s sensitivity to insulin helping your body use glucose more effectively, lowering blood sugar levels and reducing your diabetes risks.

The arrival of the pandemic has given manufacturers of NMN supplements another selling point – that it can protect against COVID-19. The logic behind this claim is sound. NMN increases NAD+ which stimulates the immune system. Having a healthy and effective immune system is key to surviving COVID-19, so it stands to reason that NMN supplementation can be helpful.

What’s difficult to quantify is how effective it is. Given how recent COVID-19 is and the comparative lack of studies, developing a reliable picture of NMN’s effect can be difficult.

Taking NMN supplements

NMN, then, sits at the heart of our health and well-being. It stimulates molecules which play an integral part in the way our bodies work and, as such, can be linked to all sorts of benefits from heart health to physical fitness, metabolism, cognition and much more. It is one of those things that the body needs to keep itself young, which means more and more people are looking to increase their intake.

Unfortunately, although NMN can be found naturally in foods such as broccoli, avocados, cabbage and cucumbers, it is impossible to get enough through your daily diet to make a significant difference.

Dosages and side effects

Finally, we come to the issue of dosages. Because NMN is not FDA approved, there is no official dosage. Companies will usually have their own recommendations which they have come to via trial and error. In mice studies, doses of several hundred milligrams were shown to have no harmful effects. Scaling up to human size would be impractical, but most human supplements recommend taking one or two tablets a day with doses of around 300mg.

A clinical trial in Japan, meanwhile, showed that there were no safety issues for humans with dosages up to 500mg. Another study using 100mg for mice extrapolated that the ideal dose would be 500mg for people up to the age of 50 and 750mg for people over that age. Generally speaking, then, NMN has been found to be safe with no real side effects to speak of.

Ready for NMN?

In the fight against aging, then, NMN appears to be a powerful weapon. It appears to successfully boost NAD+ levels and has no harmful side effects. Studies suggest all sorts of health benefits including long term effects such as improved heart condition and reduced risks of certain diseases; and short-term benefits such as helping you feel sharper, more alert and more energized.

Critics will point to its costs and the relative lack of clear evidence using human trials. Low grade products can also harm the reputation of the market as a whole. However, for those looking to find an effective strategy to boost longevity and fight back the tide of aging, NMN provides some of the fuel your body needs to keep itself healthy and young.