Nicotinamide Riboside Supplementation Partially Restores Sense of Smell in Aging: Preclinical Findings

Synopsis

Loss of smell is an early and common feature of both aging and neurodegenerative diseases such as Alzheimer's and Parkinson's. This study investigated behavioral and molecular changes in the olfactory system of aging mice. Researchers found that odor discrimination declined earliest, followed by reduced sensitivity and detection, while habituation remained intact. Molecular analyses revealed increased oxidative stress markers, DNA damage, inflammation, and reduced NAD+ levels in the olfactory bulb of aged mice. Supplementing NAD+ by administering nicotinamide riboside (NR) in drinking water extended lifespan and partially improved olfactory function. These findings highlight NAD+'s important role in preserving smell and suggest NR supplementation as a potential intervention to mitigate age-related olfactory decline.

Journal

Aging Cell