Evidence Level
Spermidine longevity research is anchored by the Bruneck Study (Eisenberg et al., 2016), a 20-year prospective cohort study that found a striking inverse relationship between dietary spermidine intake and mortality. Madeo et al. (2018) published a comprehensive review of spermidine's molecular mechanisms, confirming its role as the most potent natural autophagy inducer. Wirth et al. (2018) conducted the first placebo-controlled trial showing cognitive benefits in older adults with subjective memory decline. The autophagy mechanism is well-characterized — spermidine inhibits EP300 acetyltransferase, leading to deacetylation of autophagy-related proteins and activation of the autophagy pathway. While the epidemiological and mechanistic evidence is compelling, large-scale interventional trials specifically measuring lifespan or healthspan outcomes are still needed.