Nutrition for anti-aging
But, before your race out to pump up your B3 with yeast, bran or liver you might want to read on, there's a bit more to it than that... of course being nutrition.
Let’s start at the top... NAD
NAD, or nicotinamide adenine dinucleotide, belongs to the protein family called sirtuins. NAD is a co-enzyme (a substance that assists enzymes) found in all living cells in nature. Our body takes the energy stored in carbohydrates, protein and fat and uses this energy to make the energy that the body actually uses to perform its functions. Nutrients pass into the cells of the body, such as muscle cells, and enter a cycle called the citric acid cycle with the end result being the production of energy (known as ATP).
Hang on, I thought calories gave us energy?
Not directly, while calories from food are critical in energy production, they actually assist in energy production. The energy that comes from the catabolism of nutrients in our food doesn’t directly get used in exercise or other activities in the body or brain, rather it’s used to produce a high energy substance, ATP. Our body relies on carbs and fat (stored or free in the body), and to a lesser degree protein, to pump out ATP when needed.
Ok got it! Back to NAD
We know that NAD helps reactions occur along the energy cycle, and there are a whole lot of them, it’s a hugely complex process. A reduction in NAD will mean that the energy needed to run our body is absent… you can imagine the implications; a lack of NAD is not compatible with life. We can produce NAD from the amino acids tryptophan and aspartic acid, and via a more prolonged process from niacin (B3) in our food.
Can't I just increase my intake of B3 to prop up the decline in NAD?
Certainly B3 assists in increasing the availability of NAD for cells. However, yes there it is, the ‘but’, B3 needs to be converted (hydrolysed) to make nicotinamide to finally be converted to NAD (also requiring L-tryptophan). Enter supplemental NR (nicotinamide riboside) which in studies has been shown to significantly boost NAD in far fewer metabolic steps (Brenner, 2016).
Niacin is found in some yeasts, wheat, liver, red and white meat, some breakfast cereals, some nuts and seeds, fish, cheese, cooked potato and much more. You can check out a great sources listing: https://www.dietitians.ca/Your-Health/Nutrition-A-Z/Vitamins/Food-Sources-of-Niacin.aspx
Right, we have that under our belt, let’s move onto sirtuins and how they and NAD together might help slow and even reverse aging!
The role of sirtuins
Sirtuins (which you might see written as SIRTs) appear to play a role in regulating aging and longevity. Sirtuins are involved in an extensive number of enzymatic activities in the body and a vast number of them require NAD at some point in the process. In the research some have gone as far to say that they have “remarkable abilities to prevent diseases and even reverse aspects of ageing” (Imai and Guarente, 2016), ‘reverse’, now that could be huge!
NAD and sirtuins appear to be pivotal regulators that direct communication between muscle, brain and adipose tissue. The decline of NAD and sirtuins, along with their precursors in organs, predisposes the tissue to inflammation (via the release of inflammatory markers such as cytokines), ischemia (reduced bloody flow resulting in reduced oxygen to tissue, an example is ischemic heart disease), oxidative damage which in turn can lead to degenerative conditions. Genetically it seems our longevity gene (Sir2p) may also need NAD to be switched on.
The relationship between NAD and sirtuins seems to occur at three levels:
Sirtuins and aging
We can see from the figure below that these two little beauties are involved in cell NAD appears to decline in a number of organs ranging from the pancreas, adipose tissue, muscle, liver and our brain. As NAD declines and sirtuin activity consequently drops, this compromises the communication channels between organs, for example the hypothalamus and the liver. Studies have also found that:
Where to next with NAD, NR and sirtuins?
Studies have shown positive results when NAD intermediates and co-factors have been used to slow aging. Brenner (2016) found that NR increased NAD significantly, with more recent studies indicating that NR improved mitochondrial function, protein structure and stability in mitochondrial DNA (Khan et al., 2014). Studies have also shown positive effects of NR on insulin sensitivity, assisting in physical performance and Alzheimer’s via improved bio-availability of NAD to the brain as well as a protective effect on the brain (Chi and Sauve, 2013). Imai and Guarente (2016) note that supplementation with NAD and its intermediates (nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR) which is produced by yeasts) maybe of interest in not only slowing aging but in prevention of age-related diseases.
Interestingly, if you look back over the research around NAD you’ll see that early studies were conducted on reduced caloric intake and the role this plays in NAD production (which seems is a positive one) and longevity. I mention this because if you are doing your own research and happen upon this, don’t be tempted to restrict your calories and think you’ll live longer. Caloric or energy sufficiency is also important in general health, consider, as you get older it may well be true we need to consume less energy, however many nutrients are required in greater amounts. The challenge then is to eat highly nutritious food to gain nutrient sufficiency without over consuming energy. That’s how you could interpret it through the science. Or perhaps is it to eat a highly nutritious diet that improves longevity factors to enables us to be physically active so we don’t have to worry so much about energy intake?
A lesson from the Blue Zones
Seems the main pillars of a health-filled aging process is to eat a clean, nutrient-dense, largely plant-based diet (that includes herbs, beans, peas etc), have solid social structures and purpose, avoid eating to excess, it’s okay to enjoy a tipple (ideally of antioxidant rich wine), and enjoy some good ole fashion hard yacka. Remember, variety is not only the spice of life but a simple way to get your nutrient needs.
Words by Director of Cadence Health, Leanne Cooper
We all have a role to play in community health, the only question is how do we play this role? Through intelligent, evidence-based inquiry we can understand how to health coach to support others in taking on positive behaviour change.