Requirement of NAD and SIR2 for life-span extension by calorie restriction in Saccharomyces cerevisiae.
Level 5 - mechanism / opinion, no new human data
Bench research in a non-human model organism (Saccharomyces cerevisiae)
PubMed 11000115 · doi:10.1126/science.289.5487.2126
What was done
The authors mimicked calorie restriction in the yeast Saccharomyces cerevisiae using physiological or genetic interventions and evaluated life-span in wild-type strains as well as strains with mutations in SIR2 (encoding Sir2p) or NPT1 (a gene involved in NAD synthesis).
What was found
Calorie restriction substantially extended life-span in yeast, but this extension did not occur in strains with mutations in SIR2 or NPT1. The abstract reports no numerical values, life-span durations, or effect sizes.
Why it matters
The study establishes that Sir2p and NAD biosynthesis are required for calorie restriction to extend life-span in yeast, linking nutrient availability to sirtuin-mediated longevity.
Limits
The study is restricted to a single-celled organism (Saccharomyces cerevisiae) and cannot be directly extrapolated to human aging. The abstract provides no quantitative sample sizes, survival numbers, or variance estimates.
Cited by
- supports Nutrient restriction in yeast increases intracellular NAD levels, activating sirtuins and extending yeast replicative lifespan by approximately 30%.