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Spermidine

Overview

Spermidine is a polyamine: a small molecule with three nitrogen-containing amine groups [1]. It occurs in foods, including soybeans, peas and some cheeses, and is also formed within the body [2]. It belongs to a family that includes putrescine and spermine; measurements of one do not describe the others. It is both a bioactive food constituent and an endogenous metabolite; supplemental extracts provide a different exposure.

Its biological interest concerns cellular maintenance. Experiments link spermidine to autophagy, the recycling of cellular material, and to a protein modification involved in mitochondrial function [3,4]. These findings explain research interest in ageing. However, a 12-month human trial of spermidine-rich wheat-germ extract did not improve its primary memory outcome [5]. Cellular roles and experimental longevity findings therefore do not establish a cognitive benefit from supplementation.

Dietary Origin

Food-composition research reports spermidine in plant and animal foods, with substantial variation between samples and studies. A compiled database identifies dry soybeans, green peas and some cheeses among sources; these are occurrence observations, not a ranked intake prescription [2]. Content depends on the food preparation and analytical sample.

Diet is only one source. Endogenous synthesis and intestinal microorganisms also contribute to polyamine availability [2]. Their relative contribution to an individual's brain pool is not established here. Precursor supply or microbial production must not be confused with direct spermidine content in a food.

The human memory trial used a concentrated wheat-germ extract containing spermidine together with spermine, putrescine and other constituents. It was neither isolated spermidine nor an ordinary wheat-germ meal [5].

Research Spotlights & Evidence Checks

🔬 Research Spotlight · isolated-compound

Why is spermidine studied in cellular maintenance?

Experimental spermidine administration induced autophagy in several model systems; autophagy was necessary for its lifespan effect in the organisms tested [3].

Read the evidence

This is experimental mechanism evidence. It does not establish human lifespan extension or a dietary dose. A separate fruit-fly study linked eIF5A hypusination—a spermidine-dependent protein modification—to brain mitochondrial respiration and age-related behavioural function [4].

🔎 Evidence Check · supplemental-formulation

Has a spermidine supplement been shown to improve memory?

The SmartAge trial randomised 100 older adults with subjective cognitive decline to wheat-germ extract providing 0.9 mg spermidine daily or placebo for 12 months. The primary memory outcome did not improve significantly [5].

Read the evidence

The tested outcome was mnemonic discrimination, or distinguishing similar remembered items. Exploratory findings require confirmation. This result concerns the specific extract, dose and population; it neither establishes a benefit from spermidine-containing foods nor rules out every other exposure [5].

Recipes

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Foods

7 food relationships

Natto

Fermented soybeans with unique Bacillus subtilis and vitamin K2

ContainsNatto → contains → Spermidine

Analytical food evidence identifies spermidine in natto; concentration varies with the sample and preparation.

Peas

Plant protein, fiber, and thiamine source

ContainsPeas → contains → Spermidine

Analytical food evidence identifies spermidine in peas; concentration varies with the sample and preparation.

Sesame Seeds

Whole sesame seed with unsaturated fat, minerals and lignans

ContainsSesame Seeds → contains → Spermidine

Analytical food evidence identifies spermidine in sesame seeds; concentration varies with the sample and preparation.

Soy

Complete plant protein with isoflavones (genistein) and choline

ContainsSoy → contains → Spermidine

Analytical food evidence identifies spermidine in soy; concentration varies with the sample and preparation.

Sunflower Seeds

Thiamine source and sunflower lecithin precursor

ContainsSunflower Seeds → contains → Spermidine

Analytical food evidence identifies spermidine in sunflower seeds; concentration varies with the sample and preparation.

Tempeh

Fermented soy providing probiotics and enhanced nutrient bioavailability

ContainsTempeh → contains → Spermidine

Analytical food evidence identifies spermidine in tempeh; concentration varies with the sample and preparation.

Wheat Germ

The wheat-kernel embryo, used as a concentrated grain ingredient; contains spermidine.

ContainsWheat Germ → contains → Spermidine

Analytical food evidence identifies spermidine in wheat germ; concentration varies with the sample and preparation.

Biological Regulatory Systems

Biological Regulatory System	Evidence-qualified relationship	Evidence
Mitochondrial Function & Bioenergetics (BRS4)	Experimental eIF5A hypusination evidence connects spermidine with brain mitochondrial function in fruit flies. Human mitochondrial benefit from increasing dietary intake remains unestablished.	[4]

References

[1] PubChem (2026). Spermidine, CID 1102. Chemical identity, molecular formula and InChIKey for this substance.

[2] Atiya Ali et al. (2011). Polyamines in foods: development of a food database. Food-occurrence compilation and original dairy analyses, distinguishing individual polyamines and sample variability.

[3] Eisenberg et al. (2009). Induction of autophagy by spermidine promotes longevity. Experimental autophagy and longevity evidence, without a human lifespan endpoint.

[4] Schroeder et al. (2021). eIF5A hypusination, boosted by dietary spermidine, protects from premature brain aging and mitochondrial dysfunction. Experimental evidence for a distinct protein-modification route involving mitochondrial respiration and behaviour in fruit flies.

[5] Schwarz et al. (2022). Effects of Spermidine Supplementation on Cognition and Biomarkers in Older Adults With Subjective Cognitive Decline: A Randomized Clinical Trial. Placebo-controlled wheat-germ-extract trial with no significant benefit on the primary memory outcome.