Human whole-blood NAD + levels do not vary with age or lifestyle interventions.
Level 3 - non-randomized controlled study
Analysis of seven independent human observational and interventional cohorts.
PubMed 42135539 · doi:10.1038/s42255-026-01537-5
What was done
Researchers measured whole-blood nicotinamide adenine dinucleotide (NAD+) concentrations across seven independent human cohorts using a validated ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) assay designed to account for real-world analytical variability. They evaluated how blood NAD+ levels correlated with age, lifestyle interventions, and oral nicotinamide riboside supplementation.
What was found
The abstract reports no numerical values, effect sizes, or confidence intervals. It qualitatively states that whole-blood NAD+ levels remained stable across age groups and lifestyle interventions, while changing predictably in response to nicotinamide riboside supplementation.
Why it matters
These findings challenge the widespread assumption that circulating blood NAD+ declines with normal human aging, questioning the utility of whole-blood NAD+ as a clinical biomarker for aging or lifestyle modifications.
Limits
The abstract provides no sample sizes (total participant count is unspecified across the seven cohorts), participant characteristics, or precise intervention details. Measurements were restricted to whole blood, leaving tissue-specific NAD+ dynamics unaddressed, and no numeric data or statistical measures are reported in the text.
Cited by
- contradicts By age 50, humans have approximately half the levels of NAD compared to when they were young.
- supports A recent landmark paper showed that NAD levels do not decrease in the blood over time.
- context NAD levels decline with aging.