Studies of biological processes that impact health and disease have facilitated the discovery of novel treatments for many conditions. For example, Nicotinamide adenine dinucleotide (NAD+) regulates many essential cellular functions.
Key takeaways:
- Nicotinamide adenine dinucleotide (NAD+) is universally present in all body cells, where it is an essential substance for activating and regulating numerous body functions.
- NAD+ levels naturally decline as we get older and are also diminished in diseases affecting major organs, including the kidneys.
- Several substances, when given as supplements, can raise NAD+ levels. These include the NAD+ precursors, nicotinamide mononucleotide supplements (NMN) and nicotinamide riboside (NR).
- An abundance of small animal research shows that these substances have the potential to slow, stop, or reverse certain types of acute and chronic kidney diseases.
- Supplements for NAD+ may be a promising new type of treatment, although research into its potential effects on human kidney disease is just beginning to appear.
Decreased NAD+ levels occur in experimental diseases, including those of the kidneys. Therefore, correcting abnormal NAD+ levels can control or reverse disease processes. Studies of NAD+ as a possible treatment for several human diseases are underway. This article will describe the functions of NAD+ in the kidneys and its potential use as a new form of therapy.
What is NAD+?
NAD+ is a coenzyme present in all living cells. Coenzymes are substances, often vitamins or vitamin derivatives, that are essential to the functions of enzymes in all cells.
Most NAD+ in the body is typically synthesized from dietary vitamin B3 or by “recycling of spent” NAD+ back into the synthesis pathways. Additional supplementation with several substances in the NAD+ pathway (NR and NMN) can significantly increase the production of NAD+.
Why Is NAD+ An Important Substance?
NAD+ is an important substance because it’s vital to various metabolic processes. The activities of NAD+ vary among cells, regulating numerous body functions. Without it, there is a higher risk of severe illness or death.
In the kidneys (and other organs), NAD+ is required as a coenzyme for the activation of a family of enzymes called sirtuins. They play many major biological roles in the body, including regulating critical functions in the kidney.
These functions include the regulation of blood flow, blood filtration (in the glomerulus), removing waste products and unnecessary metabolic substances (in the kidney tubules), and managing inflammation and injury associated with many kidney diseases.
Research has also shown that sirtuins can delay natural cell aging processes, and therefore are getting a great deal of attention in aging research. In both animals and humans, low levels of NAD+ also result in low sirtuin levels. Supplementation with substances that are part of the NAD+ synthesis pathway led to increased levels of NAD+ and sirtuins.
The substances that are most often used in research and human studies are NMN and NR.
Age-Related Changes Of NAD+ Levels
There is a natural decline in NAD+ levels as we get older, and by middle age, average levels decrease by more than 50%. Also, many kidney and systemic diseases reduce the availability of NAD+. Notably, since the kidneys are among the body’s top energy consumers, they are particularly vulnerable to low NAD+ levels. Therefore, sirtuin levels also decline when there is an inadequate amount of NAD+.
Abundant research in animals and a limited amount in humans show that correcting abnormally low NAD+ levels improves the health of major organs, including the kidneys. Experimental kidney disease models have been used to evaluate the effects of decreased NAD+ and the results of supplementation with NMN or NR.
The majority of these studies show that supplementation can limit cellular kidney injury, dysfunction, and tissue scarring.
In addition to the kidneys, sirtuins are essential for the health and healing of the heart, eyes, and brain, among others. They also reduce kidney injury from diabetes. These are encouraging findings, although the results of human studies are just now beginning to appear.
Is NMN & NR Therapy Promising For Kidney Diseases?
Maybe, but it’s too early to tell. The use of over-the-counter supplementation with vitamin B3, NMN, or NR is becoming more popular, primarily because of the possible anti-aging effects of NAD+. Human research studies have shown that both NMN and NR supplementation, taken orally, can replenish low levels of NAD+ and sirtuins with few to no safety concerns.
Several kidney diseases are associated with decreased levels of NAD+. However, there is very little information on humans to clarify whether supplemental NMN or NR can alter the course of these kidney diseases. By contrast, the benefits reported from small animal research studies are well-established.
These show that supplementation can protect from hypertension, atherosclerosis, abnormal lipid levels, acute and chronic kidney diseases, kidney functional loss, and progressive scarring that can lead to kidney failure.
The kidneys are not unique in this observation, although findings in other human disorders are likewise very limited. Nonetheless, early study results suggest that NMN or NR may:
- Slow or improve cognitive decline in those with Alzheimer’s and Parkinson’s diseases.
- Improve glucose metabolism in pre-diabetes.
- Enhance lower limb muscle strength and diminish fatigue in the elderly.
- Improve abnormal lipid (cholesterol) levels, including lowering LDL (“bad”) cholesterol and triglycerides, and increasing HDL (“good”) cholesterol.
Nonetheless, the benefit claims on the packaging for OTC NAD+ supplementation products must be read cautiously. This is because advertisements for B3, NMN, or NR generally claim properties that have only been proven, thus far, in animal studies.
A considerable amount of data shows that supplementation to increase NAD+ levels in experimental kidney diseases, among others, can diminish injury and preserve function. The rationale for taking OTC supplements to increase NAD+ levels in people with kidney disease is, as yet, speculative.
However, extrapolating from research study findings, this directed therapy has a great deal of promise.
