Spermidine
Spermidine — Polyamine Autophagy Inducer
What is Spermidine?
Spermidine is a naturally occurring polyamine found in high concentrations in wheat germ, soybeans, mushrooms, and aged cheese. It is also produced endogenously from putrescine in virtually all cells. Spermidine is the most potent known natural inducer of autophagy — the cellular self-cleaning process that removes damaged proteins and organelles. Like rapamycin and caloric restriction, spermidine induces autophagy through mTOR-independent pathways.
Spermidine inhibits acetyltransferases including EP300, leading to hypoacetylation of autophagy proteins and induction of the autophagic cascade. It stabilizes autophagy-initiating complexes and promotes mitophagy (selective clearance of damaged mitochondria). Unlike rapamycin, it induces autophagy without mTOR inhibition — potentially avoiding the muscle protein synthesis tradeoff. It also has epigenetic effects, reducing H3K14 acetylation and promoting youthful gene expression patterns.
Research Evidence
Spermidine supplementation extends lifespan in yeast, flies, worms, and mice. Effects are autophagy-dependent — autophagy inhibition abolishes the longevity benefit.
Observational data shows higher dietary spermidine intake correlates with lower cardiovascular mortality. A small interventional trial showed improved diastolic function in older adults on spermidine.
Human trials show spermidine supplementation improves memory in older adults with subjective cognitive decline. Autophagy induction in neurons is the proposed mechanism.
Evidence grades: Gold = RCT human data · Silver = consistent animal/human data · Bronze = limited or preliminary
Dosing Protocols
Reconstitution / Preparation
This compound does not require reconstitution — it is available as an oral or pre-mixed formulation.
Frequently Asked Questions
How does Spermidine induce autophagy differently from Rapamycin?
Rapamycin induces autophagy by inhibiting mTOR — the nutrient sensor that suppresses autophagy when nutrients are available. Spermidine induces autophagy independently of mTOR, through epigenetic mechanisms (EP300 inhibition) that directly activate the autophagic machinery. This means spermidine can potentially induce autophagy even in well-nourished states when mTOR is active, and may be less disruptive to muscle protein synthesis than rapamycin.
Which foods are highest in spermidine?
Wheat germ has the highest known spermidine content (~350 mg/kg dry weight). Other high sources include soybeans, natto, mushrooms, broccoli, cauliflower, and aged cheese. Fermented foods and matured cheeses have higher spermidine content than fresh equivalents due to bacterial polyamine production during fermentation.
References
- [1]Madeo F, Eisenberg T, Pietrocola F, Kroemer G. Spermidine in health and disease. Science. 2018;359(6374):eaan2788.
- [2]Wirth M, Benson G, Schwarz C, et al. The effect of spermidine on memory performance in older adults at risk for dementia. Cortex. 2018;109:181-188.
This profile was prepared using AI-assisted research synthesis. Citations are provided where applicable — verify with primary sources before clinical application.
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