Plain language summary
As the body ages, there is a decline in muscle mass and function, which can be combatted with diet, exercise, and supplementation. Nicotinamide riboside (NR) or vitamin B3 has been shown in animal studies to promote healthy muscle, however its effects in human muscle are unknown. This randomised control trial of overweight older men aimed to determine if NR can be used by muscle and whether it has any effect on muscle function. The results showed that NR supplementation (1 g/day) for 3 weeks can be used by the muscle but had no effect on muscle function as shown by the hand grip test. Supplementation also decreased energy production in muscle and had anti-inflammatory effects. It was concluded that NR is available to muscle and that it may have anti-inflammatory properties, which may be of benefit to older individuals.
Abstract
Nicotinamide adenine dinucleotide (NAD+) is modulated by conditions of metabolic stress and has been reported to decline with aging in preclinical models, but human data are sparse. Nicotinamide riboside (NR) supplementation ameliorates metabolic dysfunction in rodents. We aimed to establish whether oral NR supplementation in aged participants can increase the skeletal muscle NAD+ metabolome and if it can alter muscle mitochondrial bioenergetics. We supplemented 12 aged men with 1 g NR per day for 21 days in a placebo-controlled, randomized, double-blind, crossover trial. Targeted metabolomics showed that NR elevated the muscle NAD+ metabolome, evident by increased nicotinic acid adenine dinucleotide and nicotinamide clearance products. Muscle RNA sequencing revealed NR-mediated downregulation of energy metabolism and mitochondria pathways, without altering mitochondrial bioenergetics. NR also depressed levels of circulating inflammatory cytokines. Our data establish that oral NR is available to aged human muscle and identify anti-inflammatory effects of NR.
Methodological quality
Jadad score
:
2
Allocation concealment
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Yes
