[Apr. 29, 2023: Staff Writer, The Brighter Side of News]
Research supports the idea that NR can alter the metabolism of relevant biological pathways involved in neurodegenerative diseases like Alzheimer’s. (CREDIT: Creative Commons)
University of Delaware researcher, Christopher Martens, and Dr. Dimitrios Kapogiannis, a senior investigator at the National Institute on Aging, have found that nicotinamide riboside (NR), a naturally occurring dietary supplement, can enter the brain. This is significant because it supports the idea that NR can alter the metabolism of relevant biological pathways involved in neurodegenerative diseases like Alzheimer’s.
This discovery, supported by an NIH grant and the Intramural Research Program of the NIH National Institute on Aging, was recently published in Aging Cell.
NR is converted into nicotinamide adenine dinucleotide (NAD+), which is critical to cellular repair and the repair of damaged DNA. As we age, we gradually lose NAD+, and this loss is linked to obesity and negative lifestyle habits like smoking.
NR boosts the levels of NAD+ in the blood, and in the initial study, lower blood pressure was observed in individuals who had high blood pressure. However, it was unknown if NR could reach other tissues in the body to have a real therapeutic effect.
Measuring the level of NAD+ in the brain is challenging. There are emerging techniques involving MRI, but they are costly and difficult to perform. Martens and his colleagues measured NAD+ directly in tiny particles called extracellular vesicles, which originated from neurons and ended up in the blood.
These extracellular vesicles provide blood-based biomarkers for brain disorders and serve as a “liquid biopsy” of neurons, giving researchers a rare look at what’s inside them.
Samples from the initial clinical trial revealed that NAD+ levels went up in these vesicles after six weeks. Martens and Kapogiannis found that there was a correlation between neurodegenerative biomarkers and a change in NAD+. Martens is currently leading a 12-week study involving NR in older adults with mild cognitive impairment to determine whether increased consumption of NR has a larger effect on individuals with cognitive impairment.
Christopher Martens, director of the Delaware Center for Cognitive Aging Research, is leading a study into whether nicotinamide riboside (NR) improves memory and brain blood flow in older adults with mild cognitive impairment. (CREDIT: University of Delaware)
In the ongoing trial, markers of cognitive function and other things related to functional independence and quality of life are being measured. Martens hopes that the people who take NR might have preserved function. After proving its efficacy, Martens and Kapogiannis will test whether increased use of NR improves cognition and whether it can be used to slow neurodegenerative disease progression.
NR is found in trace amounts in milk, yeast, and beer, and in larger amounts in whey protein powder. However, it is uncertain if the NR found in these sources can increase NAD+ levels in the brain. Martens’ work on NR suggests that increasing NAD+ levels could be a viable treatment for neurodegenerative diseases like Alzheimer’s.
NAD+ and NADH concentrations in NEVs and change–change correlations with insulin signaling proteins. (a) Concentration of NAD+ after 6 weeks of oral nicotinamide riboside (NR) supplementation was significantly higher in NEVs when compared to placebo. (CREDIT: Aging Cell)
The potential impact of the findings is significant. Alzheimer's disease is the most common cause of dementia, affecting more than 5 million Americans and costing more than $305 billion each year. There are currently no disease-modifying treatments available for Alzheimer's, and existing drugs can only provide temporary relief of symptoms. Finding a way to slow or stop the progression of the disease would have enormous benefits for patients and their families, as well as for the healthcare system as a whole.
The use of NR as a dietary supplement is already popular in some circles, with claims that it can improve energy levels, promote weight loss, and support healthy aging. While these claims are not yet supported by rigorous scientific evidence, the discovery that NR can enter the brain and potentially affect the underlying mechanisms of neurodegenerative disease could make it an even more popular and widely used supplement.
NEV biomarkers in response to oral nicotinamide riboside supplementation. (a) Alzheimer's disease biomarkers. (b) Canonical insulin/Akt signaling mediators. (CREDIT: Aging Cell)
The researchers caution that more research is needed to fully understand the potential benefits and risks of NR, and that people should not start taking it without consulting their healthcare provider. NR is a dietary supplement, not a drug, and is not regulated by the FDA. While it is generally considered safe and well-tolerated, there is still much to learn about its long-term effects on the body and brain.
Nevertheless, the discovery that NR can enter the brain and potentially affect neurodegenerative disease is an exciting development in the field of cognitive aging research. The study highlights the importance of understanding the underlying biological mechanisms of disease and the potential role of dietary supplements in modulating these mechanisms.
NEV biomarkers in response to oral nicotinamide riboside supplementation. (c) Alternative MAPK insulin signaling biomarkers. Two-tailed paired ttest was used for all analyses; horizontal bars depict mean; error bars depict SEM. (CREDIT: Aging Cell)
Martens and Kapogiannis are continuing to study the effects of NR on the brain and are optimistic about its potential for improving cognitive function and slowing disease progression. The ongoing clinical trial is expected to provide further insights into the efficacy and safety of NR in older adults with cognitive impairment.
As the population ages and the incidence of neurodegenerative diseases continues to rise, finding effective treatments and preventative measures will be of increasing importance. The discovery that NR can enter the brain and potentially alter the metabolism of relevant biological pathways offers hope for a new approach to addressing these devastating diseases.
The Delaware Center for Cognitive Aging Research relies on the support of individuals and organizations to accelerate interdisciplinary research, education and clinical training in Alzheimer’s disease and related disorders.
For more science news stories check out our New Discoveries section at The Brighter Side of News.
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