Nicotinamide riboside nr
Pro Research Analysisby 
Searched over 200M research papers
The Role of Nicotinamide Riboside (NR) in Health and Disease
Introduction to Nicotinamide Riboside (NR)
Nicotinamide riboside (NR) is a precursor to nicotinamide adenine dinucleotide (NAD+), a crucial coenzyme involved in various metabolic processes. NR has garnered significant attention due to its potential health benefits, particularly in aging, metabolic disorders, and inflammation.
NR and Aging: Enhancing Muscle Function and Reducing Inflammation
Muscle NAD+ Metabolome and Anti-inflammatory Effects
Research has shown that NR supplementation can significantly elevate the NAD+ metabolome in aged human skeletal muscle. A study involving 12 aged men demonstrated that 1 g of NR per day for 21 days increased nicotinic acid adenine dinucleotide and nicotinamide clearance products in muscle tissue. Additionally, NR supplementation was associated with a reduction in circulating inflammatory cytokines, suggesting its potential anti-inflammatory benefits .
Physical Performance and Muscle Quality in Mice
In middle-aged mice, short-term NR supplementation improved physical performance, muscle quality, and cellular energetics. NR increased total NAD+ levels in muscle tissue, enhanced treadmill endurance, and prevented the decline in grip strength. These findings support the potential translation of NR supplementation to improve health span during aging .
NR in Metabolic Health: Mixed Results in Human Studies
Insulin Sensitivity and Metabolic Parameters
Despite promising preclinical results, human trials have shown mixed outcomes regarding NR's effects on metabolic health. A 12-week study in obese, insulin-resistant men found that NR supplementation did not improve insulin sensitivity, glucose metabolism, or body composition. However, the study confirmed the safety of NR at doses of 2000 mg/day .
Body Composition and Skeletal Muscle Metabolism
Another study in healthy overweight or obese individuals reported that 6 weeks of NR supplementation increased skeletal muscle NAD+ metabolites and acetylcarnitine concentrations. While there were minor improvements in body composition and sleeping metabolic rate, no significant effects on insulin sensitivity, mitochondrial function, or other metabolic health parameters were observed .
NR and Inflammation: Potential Benefits in Reducing Inflammatory Markers
Clinical Evidence of Anti-inflammatory Effects
Several clinical trials have investigated NR's impact on inflammation. While results varied, some studies reported significant reductions in inflammatory markers such as IL-6 and IL-18. These findings suggest that NR may help mitigate chronic inflammation, particularly in populations with higher inflammation status, such as the elderly or those with metabolic disorders .
NR in Liver Health: Reducing Liver Fibrosis
Anti-fibrotic Effects in Mouse Models
In a diet-induced mouse model of liver fibrosis, NR supplementation significantly reduced liver fibrosis markers, including collagen content and hepatic collagen 1a1 mRNA and protein levels. The study indicated that NR might directly reduce hepatic stellate cell activation, suggesting its potential as a preventative treatment for liver fibrosis .
NR Bioavailability and Sources
Bioavailability in Humans and Mice
NR is uniquely bioavailable in both humans and mice. Studies have shown that oral NR can significantly increase blood NAD+ levels, with dose-dependent effects observed in clinical trials. This bioavailability makes NR a promising candidate for therapeutic use .
NR in Cow Milk
Interestingly, NR is a major NAD+ precursor vitamin found in cow milk. Research has shown that cow milk contains significant concentrations of NR, which is stable and bioavailable, making it a potential dietary source of this important compound .
Conclusion
Nicotinamide riboside (NR) holds promise for enhancing NAD+ levels, improving muscle function, reducing inflammation, and potentially preventing liver fibrosis. While human studies have shown mixed results regarding its metabolic benefits, NR's safety and bioavailability make it a valuable candidate for further research and therapeutic use. As our understanding of NR's effects continues to grow, it may become an essential component in strategies aimed at improving health span and managing age-related conditions.
Sources and full results
Most relevant research papers on this topic