NAD stands for Nicotinamide Adenine Dinucleotide, and is a compound known as a “coenzyme”. Coenzymes are essential for the functioning of enzymes, and enzymes are the primary regulators of all chemical reactions in your body. They are critical for digestion and energy metabolism, which allow us to speak, think and move!

NAD was discovered in 1906, and its importance was slowly uncovered over the next 120 years. Even in 1930, Euler-Chelpin, in his Nobel Prize speech, referred to as “one of the most widespread and biologically most important activators within the plant and animal world.”

NAD is constantly being naturally produced and recycled by your body, keeping levels as high as possible. Are NAD levels are boosted by the food we eat in various forms of Vitamin B3, including Niacin, Nicotinamide, Nicotinamide Mononucleotide, and Nicotinamide Riboside.

NAD is essential in every cell in your body as it plays a central role in your cells’ ability to transform the food we eat into cellular energy. You produce lots of it when you’re young, but as you get older, your NAD levels naturally decline, meaning your cells have less energy from the nutrients you consume to maintain their healthy functions.

How it works

Most living cells produce energy from nutrients through a process called cellular respiration. Cellular respiration refers to the breakdown of the food we eat, such as glucose, carbohydrates, lipids and proteins, into more useful energy-carrying molecules used in cells called Adenosine Triphosphate (ATP).

For cellular respiration, the extraction of energy from food molecules is what is known as oxidation. Oxidation means removing hydrogen, which in this case is equal to 2 high-energy electrons, from the food molecule.

The importance of NAD lies here. NAD acts as the transporter, or carrier, of the hydrogen in this process and exists in two forms, NAD+ and NADH, depending on whether it is carrying hydrogen or not.

NAD+, which is the form when not carrying electrons, collects hydrogen/electrons from the nutrients and food molecules we consume, transforming NAD+ into NADH.

NADH then transports and donates the electrons to cells, enzymes and proteins that need energy vital for life! With each transfer of electrons, through the chemical reactions that occur, cellular energy – ATP is generated!

Once NADH has donated its hydrogen and no longer has its hydrogen atom, it transforms back to NAD+ and begins the cycle again.

Powering the Mitochondria

Mitochondria are tiny batteries within each cell that are the source of cellular energy. To make that energy, a series of chemical reactions must occur within the mitochondria.

There are three stages to creating cellular energy (ATP) by cellular respiration. The most, by far, is produced through NADH delivering electrons directly to the inner membrane of a cell’s mitochondria, where they transfer to a structure called the electron transport chain.

Fewer nutrients are processed by the mitochondria when there are fewer NAD transporters, leading to lower ATP production.

The mitochondria are made up of an outer membrane, an inner membrane, the space in between called the intermembrane space, and the matrix – the center of the mitochondria.

The electron transport chain is a collection of carrier proteins. Carrier proteins are essential molecules which facilitate the movement of hydrogen ions and electrons across the inner membrane, between the matrix and intermembrane space.

The electrons delivered by NADH create energy for the carrier proteins to “pump” hydrogen ions from the center of the mitochondria (the matrix) across the inner membrane to the intermembrane space.

As the mitochondria require a relatively equal amount of hydrogen ions on either side of the inner membrane, the hydrogen ions naturally “pumps” back through.

This flow of positive charges back across the inner membrane through a protein called ATP synthase produces ATP – energy for the cell.

Enzymes - vital for life

Enzymes are molecules that initiate and significantly speed up the rate (by the millions!) of virtually all chemical reactions occurring within cells. They ensure the result of these chemical reactions is what our body needs, and they need NAD to work.

They are vital for life and serve a wide range of essential functions in the body. They break down larger molecules into smaller ones and combine other molecules to make new ones. They are responsible for creating the energy and molecules your body needs to help with digestion, metabolism, cell renewal and growth. The ATP synthase, discussed above, is an enzyme critical for creating the cellular energy – ATP.

Sirtuins - Protectors of the Genome

Sirtuins (or Silent Information Regulator) are essential to maintaining a cell’s health and stability. They are regularly known as “protectors of the genome”, as they keep your cells’ compositions balanced so that they can perform as they should.

There are 7 sirtuins in total (SIRT1 through to SIRT7). We are only beginning to understand the full extent of their roles and responsibilities. Here are some of their potential roles from published journals. *This is only a tiny proportion of the information available.*

SIRT1: Regulate inflammation and metabolism (click here)
SIRT2: Tumor Suppressor (click here) and protects neural cells from oxidative stress (click here)
SIRT3: Eliminate reactive oxygen species and to prevent the development of cancerous cells (click here)
SIRT4 Tumor Suppressor (click here) and cellular energy metabolism (click here) 
SIRT5: Regulate urea cycle (click here) and energy metabolism (click here) 
SIRT6: Telomere maintenance (click here) and DNA repair (click here) 
SIRT7: Gene expression and cellular metabolism (click here) 

Calorie restriction stimulates sirtuin activity, which is why the popularity of fasting has grown recently as an anti-ageing strategy. Resveratrol and Pterostilbene, also, act to stimulate SIRT-1 with Curcumin shown to upregulate SIRT 1, 3, 5, 6, and 7.

PARPs

PARPs help repair DNA when it becomes damaged. DNA damage is caused by many things, including exposure to UV light, radiation, disease, or other environmental substances.

Their primary role is detecting and initiating an immediate cellular response to metabolic, chemical, or radiation-induced single-strand DNA breaks.

Once the PARP has detected DNA damage, it binds to it and signals the DNA repair pathways to direct them to the site and carry out the repair.

Watch the excellent video below of Prof. Steve Jackson, the Head of Cancer Research UK, describing the function of PARPs.

NAD is essential for Sirtuin and PARP activation

Sirtuins and PARPs require NAD to function correctly, quickly using up NAD, demanding that the body constantly synthesises it.

Researchers now believe that when NAD levels increase, sirtuins and PARPs are activated, leading to significant health benefits.