Supplementation with NAD+ Precursors for Treating Alzheimer's Disease: A Metabolic Approach.

BACKGROUND

Alzheimer's disease (AD) is a progressive neurocognitive disorder. There is no cure for AD. Maintenance on intracellular levels of nicotinamide adenine dinucleotide (NAD+) has been reported to be a promising therapeutic strategy for the treatment of AD. NAD+ precursors that represent candidate targets include nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR).

OBJECTIVE

This systematic review provides insights into the potential therapeutic value of NAD+ precursors including NMN and NR, for the treatment of AD using preclinical and clinical studies published in the last 5 years.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol was followed to systematically search the literature using two databases.

RESULTS

We found 3 studies that used NMN to treat AD in preclinical murine models. However, human clinical trials using NMN as a therapeutic intervention in AD was not available in the current literature. We also found 4 studies that investigated the potential benefits of NR for the treatment of AD in preclinical models. We also found 2 human clinical trials that showed marked improvements in plasma and neuroimaging biomarkers, and cognitive measures following supplementation with NR.

CONCLUSIONS

Results of preclinical and clinical studies confirm the potential benefits of NAD+ precursors for the treatment of AD. However, further clinical studies are required to confirm the increasingly important value of NAD+ precursors as effective pharmacological interventions in the clinic.