Nicotinamide Mononucleotide (NMN) is a supplement that seldomly comes onto most people’s radar, yet it is a supplement that holds a promising future with some researchers suggesting NMN should become a staple supplement to help improve longevity. Melbourne sports chiropractor Dr. Nicholas Shannon takes a look at literature on NMN to see if it is something you should consider.
What is NMN and How Does NMN Work?
NMN is synthesized in the body via two pathways, the Salvage and Preiss-Handler pathways, with the former synthesizing NMN from vitamin B3. Once synthesized, NMN acts as a precursor to a metabolic coenzyme called NAD+ (nicotinamide adenine dinucleotide).
NAD+ is an important coenzyme involved in a variety of processes including cell death, aging, gene expression, neuroinflammation and DNA repair.
NMN is found naturally in plant and animal sources including soybeans, broccoli, avocado, tomatoes, cucumbers, mushrooms, raw beef and shrimp. The levels of NMN in these food sources vary from around .25mg/100g to 1.88mg/100g. For comparison, studies investigating the efficacy of supplementing with NMN range from 250mg to 2000mg per day.
Why is NMN and NAD+ important in aging?
As we age there is a reduction in energy production in the mitochondria (the power factory of cells) in a variety of organs including the brain, adipose tissue, skin, liver, skeletal muscle and pancreas as a result of decreased NAD+ levels. This depletion of NAD+ occurs naturally with aging, due to an increase in consumptions of NAD+ consuming enzymes. Additionally, the metabolic pathway which produces NAD+ can be inhibited by chronic inflammation, high fat diets and, oxidation which can further negate the levels of NAD+ in the body. This in part, leads to biological changes associated with aging such as, reduced endurance, strength, cognitive impairment and DNA damage.
Supplementation with NMN has been shown to boost NAD+ levels by 2-3 times. Furthermore, fasting, and reducing energy intake may also improve NAD+ levels. It is for this reason, NMN supplementation research has moved from NMN being a source of cellular energy and a precursor to NAD+, to it’s potential impact on other disease such as age-induced type II diabetes, obesity, cerebral and cardiac ischaemia, heart failure and cardiomyopathies, Alzheimer’s disease (AD) and other neurodegenerative diseases, corneal injury, macular degeneration and retinal degeneration and acute kidney injury.
Safety and Efficacy of NMN
NMN has been extensively studied in mice and rodents, where results have shown significant improvements across a variety of areas including AD, age-related physiological changes, as well as renal, cardiac, vascular and skeletal muscle function. However, impressive results in animal studies do not necessarily correlate to the same changes in humans.
The first step in the human trial process is to establish if an intervention is safe, efficacious (does it work) and if are there any adverse reactions. To this author’s knowledge, there are at least 9 randomized controlled human trials which have explored dosage ranges from 250mg to 2000mg per day, over various time periods ranging from 30 days to 3 months, across a variety of groups; healthy middle aged adults, healthy older aged adults, recreational athletes, obese and overweight, males and females.
These studies have consistently shown NMN is safe and well tolerated. The data is favourable to seeing an increase in NAD+ concentrations in the blood, however it should be noted there have been some studies which haven’t shown a statistically significant change. Furthermore, it should be noted that currently there is no agreed definition of what low, normal or high NAD+ levels are.
Reported Benefits of NMN
A 2023 randomized, controlled, double blinded placebo trial (the gold standard study design) investigating the effects of NMN at 300mg, 600mg and 900mg versus placebo on a cohort of 80 healthy male and female adults over 60 days, found increased blood concentrations of NMN, significantly improved 6 minute walking test (endurance), minimal to no change in blood biological age, and improved health scores (SF-36 questionnaire) in the NMN groups compared to placebo. In addition to NMN being safe and well tolerated across all doseage levels.
Additional clinical trial data has shown the following.
- Sleep – no detectable changes in sleep quality scores
- Physical activity (older adults) – significantly improved gait speed, grip strength, 30s chair-stand test indicating a potential prevention in age-related muscle decline
- Physical activity (middle-aged adults) – significantly increased oxygen consumption in ventilation and energy consumption. In addition to significantly improved aerobic capacity when exercise and NMN were combined, suggesting NMN could be used to improve athletic performance
- Nervous system-related – improvements in hearing in older adults, no change in cognition or vision
- Diabetes – improved muscle insulin sensitivity which may improve impaired glucose tolerance
- Anti-aging – significant improvement in telomere (a biomarker for monitoring aging)
Where To From Here?
The early human data for NMN looks promising, it’s safe, it is well tolerated, and there is evidence in adults that NMN may play an important role in anti-aging. The data specifically related to improvement in endurance and strength for older and middle-aged adults looks extremely promising, and this should be an area of great interest to those in the sports and exercise medicine field.
Overall, the early data suggests NMN might have a bright future, which will be solidified as more data comes out. Some of that data needs to provide clarity to understand the full impacts of NMN supplementation on the body; to establish agreed measurements of NAD+ to determine what are low, normal and high levels; to identify if there are specific age-related dosages; and to study the safety of NMN supplementation over the long term (years).
It is also important to note that supplementation is only one component to improving health and longevity. Additionally sleep, diet, fasting and exercise are essential to the process.
If you are interested in exploring the benefits of NMN for yourself, Melbourne sports chiropractor Dr. Shannon has analysed the market providers and prefers Renue by Science, as their products are third party tested to confirm their supplements purity, and their manufacturing plant is FDA approved. To read more about why third party testing is important for supplements have a read of our blog on sports supplements.
If you would like to book an appointment a chiropractic or massage appointment at our Melbourne city chiropractic clinic on Collins Street in the Melbourne CBD, click on the link below.