Blood NAD+ Levels Stay Flat With Age, Challenging Popular Aging Theory
Graded Strong — seven independent human cohorts measured with a rigorously validated mass spectrometry method, with results consistent across all of them.
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- Authors declare no competing interests.
This study suggests blood NAD+ tests may not reliably reflect biological age.
One of the most repeated ideas in longevity is that NAD+ declines as we age, a story that helped make NR and NMN household names in the space. This large, carefully controlled study takes a closer look. Across seven independent cohorts and more than 300 people, researchers found that whole-blood NAD+ levels stayed remarkably stable with age, and didn't shift meaningfully in response to exercise, protein-rich diets, or multimodal lifestyle interventions in older adults. Importantly, NR supplementation did raise blood NAD+ as expected, confirming that the supplements work pharmacologically, the question is just whether blood NAD+ is the right thing to be measuring in the first place.
Conflict of Interest Disclosure: Authors declare no competing interests.
Disclaimer: Research summaries are provided for informational purposes only and do not constitute medical advice. Always consult a qualified healthcare professional before making changes to your health routine.
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