What Happens to NAD+ Levels by Age?
So now you’ve heard what NAD is, here’s how NAD changes in your body over time. This is relevant because it could be having an impact on your performance in the gym, your running times or how long it might take you to recover from a hike. But when did this start happening and will it get worse? Here’s the science we know so far….
Our NAD+ Levels Half Every 20 Years
Scientists have discovered that our levels of NAD+ decline by around 50% every 20 years. Low NAD+ levels are a problem because NAD+ plays a vital role in the way our body works and we cannot live without it. When levels of NAD+ are low it gets harder for our cells to produce energy, repair DNA and switch-on biomolecular maintenance pathways that protect our cells.
If low NAD+ levels persist over time our cells suffer from cumulative damage that leads to many of the symptoms, and negative health consequences, we associate with aging.
Why do we lose NAD+?
There are two main reasons that are known to cause falling NAD+ levels:
Firstly, because our cells cannot absorb NAD directly from the nutrients in our food, they have to manufacture it for themselves and this is what goes wrong as we get older. In young, healthy bodies, the cell can make NAD+ from precursor ingredients and recycle used NAD+ to make more. This latter recycling process is called the salvage pathway and it is important because it is the main way young cells make NAD+
The NAD Recycling Pathway Declines with Age
The problem is that old cells are not as good as young cells at manufacturing NAD. This is because the main enzyme required for making most of our NAD in the important recycling salvage pathway, NAMPT, declines with age.
In fact, in young cells the majority of NAD+ is continually recycled via this pathway. When NAD+ is used up during cellular repair and maintenance it is broken down into a waste product called nicotinamide. This nicotinamide then enters the salvage pathway and is recycled back into fresh NAD+. When this recycling process works with youthful efficiency it makes all of the NAD+ our cells need to stay healthy. Unfortunately, older cells do not have the recycling capacity they once did, so over time our levels of NAD+ decrease as cells struggle to recycle nicotinamide back into NAD+. Instead the nicotinamide becomes methylated, gets removed from the cell and is wasted.
Older Cells Use Up More NAD
The second factor leading to NAD+ decline is that NAD is used up much faster in old cells. This is because they have to work harder to fix damage that has accumulated throughout life.
In general, older cells have more damage, more inflammation and need more repair. This means NAD+ dependent repair processes are turned up and are consuming large amounts of NAD+ and creating waste nicotinamide in the process.
This would be fine if our cells maintained their youthful ability to recycle this nicotinamide back to NAD+ but for the reasons described above, they don’t.
Higher Demand, Lower Supply
This means that right at the time in our lives when our cells could do with more NAD+, they become less efficient at producing it - resulting in a deficit. This imbalance between NAD recycling efficiency and rising NAD demand explains why our levels of NAD decline by around 50% every 20 years. This means critical cellular processes have to fight over a short supply of NAD+ that continues to shrink as the years pass.
To help the body increase its supply of NAD in the most effective, efficient and sustainable way, the cell’s production mechanisms need to be reactivated. But the biology is complex with a number of different enzymes, pathways and subprocesses influencing the production process. Reactivating the body’s ability to make its own NAD, therefore, requires a multifactorial approach that addresses the whole system.
Find out more about a New Whole System Approach to boosting NAD.