(P11-034-23) Aging-Related Sensory Benefits From Dietary NAD+ Precursor Supplementation

Objectives: Aging can significantly alter sensory thresholds, potentially impairing lifestyle and quality of life. Within the sensory intrinsic capacity domain, popularized by the World Health Organization, vision and hearing losses tend to have the greatest impact on older adults. The essential cellular coenzyme, nicotinamide adenine dinucleotide (NAD), has also been shown to decline with age, and may be associated with sensory loss. NAD decline is positively correlated with sensory loss in animal models. Therefore, it is proposed that dietary supplementation with the NAD-precursor nicotinamide riboside (NR) and its extracellular precursor nicotinamide mononucleotide (NMN) may reduce human age- and disease-related sensory deficits.

Methods: A systematic review of the literature of NR and NMN intervention studies with vision, hearing, smell, taste, and touch outcomes were conducted utilizing PubMed. The purpose of this analysis was to determine if the existing preclinical literature supports a causal relationship of NAD levels and sensory function with age and the translation to human studies.

Results: A total of 20 peer-reviewed NR and NMN intervention publications were found to have outcomes related to three of the five senses, hearing, vision, and touch. Of these, 8 studies demonstrated a correlation between NAD and the related outcome. NR administration conferred benefits to peripheral neuropathy, retinal degeneration, glaucoma, diabetic neuropathy, noise and age-induced hearing loss, and Cockayne syndrome. NMN injection was shown to improve retinal degeneration. Oral supplementation was utilized in 3 of the mouse studies in the areas of hearing, vision, and touch. An oral NR supplementation study on age-induced hearing loss demonstrated benefits to hearing while another study showed thermal insensitivity benefits. A single oral NMN supplementation study showed improvements in eye function.

Conclusions: As there were a limited number of oral supplementation studies, conclusions about the causal relationship of NAD and sensory function with age and translation to human studies cannot be concluded and warrant additional studies. Ongoing registered clinical trials are beginning to include these outcomes while investigating peripheral neuropathy from chemotherapy and diabetes, glaucoma, and smell and taste in Long COVID.

Funding Sources: None