Why this matters for skin health and healthy ageing
One of the biggest discoveries in modern longevity research is that ageing is not caused by one single problem. Instead, ageing develops because numerous repair systems within our cells gradually become less efficient over time. Scientists describe these as the Hallmarks of Ageing. Rather than acting independently, each hallmark influences the others. Once one repair system begins to fail, others gradually become affected, creating a cascade of biological ageing throughout the body. This is why researchers increasingly believe that supporting multiple cellular repair pathways simultaneously is more effective than targeting just one mechanism.
What is NAD+?
NAD+ (Nicotinamide Adenine Dinucleotide) is a naturally occurring coenzyme found inside every living cell. It is essential for life. Without NAD+, cells cannot efficiently:
- produce energy
- repair damaged DNA
- respond to oxidative stress
- maintain healthy mitochondria
- activate longevity proteins known as sirtuins
- regulate inflammation
- recycle damaged proteins
- support healthy cell communication
Every second, trillions of cellular reactions depend on NAD+.
Why do NAD+ levels decline?
As we age, cellular NAD+ gradually falls. Several factors contribute:
- natural ageing
- chronic inflammation
- oxidative stress
- ultraviolet radiation
- poor sleep
- obesity
- chronic disease
- alcohol
- smoking
- inactivity
- increased activity of enzymes such as CD38 that consume NAD+
Lower NAD+ means cells become less efficient at repairing themselves. Damage begins to accumulate faster than repair. This is one of the defining features of biological ageing.
NAD+ influences every Hallmark of Ageing
1. DNA Damage
Every day our DNA is damaged by:
- UV light
- pollution
- cigarette smoke
- inflammation
- normal metabolism
NAD+ helps activate DNA repair enzymes including PARPs and sirtuins. Lower NAD+ means DNA damage accumulates more rapidly. For skin this contributes to:
- pigmentation
- premature ageing
- reduced cellular function
2. Cellular Senescence
Damaged cells eventually stop dividing. These "senescent" or "zombie" cells remain alive but release inflammatory chemicals that damage surrounding healthy tissue. Research suggests higher NAD+ availability may help reduce the development of cellular senescence by improving cellular repair before cells reach this dysfunctional state. Most evidence remains preclinical. In skin this may contribute to:
- slower healing
- collagen loss
- chronic inflammation
3. Epigenetic Changes
Genes rarely change. What changes is which genes are switched on or off. NAD+ activates sirtuins that help maintain healthy gene regulation. This is one reason NAD+ is sometimes described as helping cells behave more "youthfully."
4. Mitochondrial Dysfunction
Mitochondria produce cellular energy (ATP). Healthy mitochondria are essential for:
- collagen production
- skin repair
- wound healing
- barrier function
- immune defence
NAD+ supports:
- mitochondrial energy production
- formation of new mitochondria
- removal of damaged mitochondria (mitophagy)
Reduced NAD+ contributes to reduced cellular energy and increased oxidative stress.
5. Telomere Dysfunction
Telomeres protect the ends of chromosomes. As they shorten or become dysfunctional, cells lose their ability to divide normally. Animal and laboratory studies suggest NAD+ may support telomere maintenance, but convincing evidence that NAD+ supplementation preserves telomeres in humans is still lacking.
6. Chronic Inflammation (Inflammaging)
Low-grade inflammation slowly increases with age. This chronic inflammation:
- breaks down collagen
- damages elastin
- slows repair
- weakens immunity
NAD+ helps regulate inflammatory signalling through sirtuins. Reducing chronic inflammation is one of the major goals of healthy ageing.
7. Loss of Proteostasis
Proteins become damaged throughout life. Cells normally recycle or repair them. With ageing this recycling slows. NAD+ supports:
- autophagy
- protein quality control
- removal of damaged proteins
For skin this helps maintain healthy collagen and other structural proteins.
8. Altered Nutrient Sensing
Cells constantly monitor nutrient availability. NAD+ helps regulate pathways including:
- AMPK
- sirtuins
- PGC-1α
These pathways influence:
- metabolism
- insulin sensitivity
- energy production
- longevity
Lifestyle interventions such as regular exercise and calorie moderation also activate many of these pathways.
9. Stem Cell Exhaustion
Stem cells replace damaged tissues throughout life. With ageing their regenerative capacity declines.Experimental studies suggest restoring NAD+ may improve stem-cell function in some tissues, but this has not yet been proven as a rejuvenation therapy in humans.
Why this matters for aesthetic practice
Many visible signs of ageing reflect these underlying biological processes. When cellular repair slows, practitioners begin to see:
- thinning skin
- slower wound healing
- pigmentation
- collagen loss
- elastin degeneration
- reduced hydration
- impaired barrier function
- persistent inflammation
Aesthetic treatments can stimulate repair locally, but supporting overall skin health through evidence-based skincare, sun protection, nutrition, exercise, sleep, and management of systemic inflammation is also important for long-term results.
Can increasing NAD+ slow ageing?
This is one of the most active areas of longevity research. Early laboratory and animal studies are encouraging, showing that restoring NAD+ can improve several cellular processes linked to ageing. Human studies consistently show that some supplements (such as nicotinamide riboside and nicotinamide mononucleotide) can increase NAD+ levels, but evidence that they meaningfully slow biological ageing or extend healthspan in humans is still limited and under investigation.
Practical take-home message
For clients, the most effective strategy is not to rely on a single "anti-ageing" supplement. Healthy ageing is best supported by combining:
- Daily sun protection.
- A nutrient-rich diet rich in colourful plants and adequate protein.
- Regular physical activity, including resistance exercise.
- Good sleep.
- Stress management.
- Avoiding smoking and limiting excess alcohol.
- Evidence-based skincare tailored to the individual.
- Appropriate medical and aesthetic treatments where indicated.
These lifestyle measures have the strongest evidence for supporting many of the same biological pathways—including several of the hallmarks of ageing—that researchers are attempting to influence through emerging longevity therapies.
