Supplement: Spermidin

What It Is

Spermidine is a polyamine, a small molecule that your own cells make, that gut bacteria also make, and that you get from food. It was first found in semen, the source of its name, but it sits in tissues throughout the body. It turns up in almost everything you eat, most richly in wheat germ, then whole grains, legumes, mushrooms, aged cheese and fermented soy foods such as natto. Your tissue levels of it fall as you age. The reason it draws attention is one well-studied action: it switches on autophagy. In laboratory organisms, that action extends life.

What It Does

In worms, flies, yeast and mice, spermidine turns on autophagy and lengthens life. The same experiments show the life extension depends on that autophagy: block the recycling and the benefit disappears. In aged mice it also keeps the heart from stiffening. These results hold across species, and they are why spermidine moved from a biochemical curiosity to a longevity candidate. The key papers appeared in 2009 and 2016.

People with more spermidine in their diet live modestly longer. That is an observational pattern in people who tend to eat and live well in other ways, so it cannot prove the molecule did anything. When the compound was given as a supplement and tested directly, the one adequately sized trial found no effect on memory, its main measure. The dietary cohort was published in 2018, the supplement trials after that.

Taking spermidine in the hope of slowing your own aging is an experiment with an effect no human trial has measured.

The Research & Studies

Everything here is based on the research we have collected and checked, sorted into groups and ordered with the strongest evidence first. Click any claim to open the studies behind it.

How it works

Spermidin schaltet die Autophagie ein, und das Blockieren der Autophagie beseitigt seinen LebensdauernutzenModerate · mixed

In plain terms

Spermidin schaltet die Autophagie ein, den Prozess, den eine Zelle verwendet, um ihre eigenen abgenutzten Teile auszuräumen und zu recyceln, und dieser Schalter ist es, der es ermöglicht, das Leben in einfachen Labororganismen zu verlängern. Wenn Forscher die Autophagie blockieren, verschwindet der lebensverlängernde Effekt.

In detail

Eisenberg et al. (2009, Nature Cell Biology) zeigten, dass Spermidin die Histonacetyltransferaseaktivität hemmt, Autophagie auslöst und die Lebensdauer in Hefe, Fliegen, Würmern und menschlichen Immunzellen in Kultur verlängert. Genetische oder pharmakologische Blockade der Autophagie hob den Lebensdauernutzen auf und etablierte Autophagie als vermittelnden Mechanismus, nicht als Korrelat. Dies ist die gut charakterisierte mechanistische Basis für das Interesse an Spermidin.

The study · 1

Eisenberg et al., Induction of autophagy by spermidine promotes longevity · Nat Cell Biol 2009;11(11):1305-1314

Counts once: this finding and 1 other here come from the same source, so they are one body of evidence, not separate confirmations.

Cognition

Kein Gedächtnisnutzen von 0.9 mg/Tag Spermidin über ein Jahr bei 100 älteren ErwachsenenModerate · no effect

In plain terms

In der bisher größten Studie schnitten ältere Erwachsene mit Gedächtnisbeschwerden, die täglich über ein Jahr ein Weizenkeimextrakt-Spermidin-Supplement einnahmen, beim Hauptgedächtnistest nicht besser ab als diejenigen, die ein Placebo einnahmen.

In detail

Die SmartAge-Studie (Schwarz et al. 2022, JAMA Network Open) randomisierte 100 Erwachsene im Alter von 60-90 Jahren (49 % weiblich) zu 0.9 mg/Tag Spermidin aus Weizenkeimen oder Placebo über 12 Monate. Der primäre Endpunkt, mnemonische Diskriminierung auf dem Mnemonic Similarity Task, zeigte keinen Zwischen-Gruppen-Unterschied (-0.03; 95-%-KI -0.11 bis 0.05; P = 0.47), und sekundäre Endpunkte blieben unverändert. Explorative Analysen zeigten mögliche Effekte auf verbales Gedächtnis und Entzündung, die die Autoren als Bestätigung bei höheren Dosen benötigend beschrieben.

The study · 1

Schwarz et al., Effects of Spermidine Supplementation on Cognition and Biomarkers in Older Adults With Subjective Cognitive Decline (SmartAge trial) · JAMA Netw Open 2022;5(5):e2213875

Ein 30-Personen-Pilotversuch deutete auf einen Gedächtnisgewinn hin (Cohen's d 0.77), den die größere Studie nicht bestätigtePreliminary

In plain terms

Eine kleine dreimonatige Studie mit 30 älteren Erwachsenen deutete darauf hin, dass ein Spermidin-Supplement das Gedächtnis etwas verbesserte. Die Studie war zu klein, um darauf zu vertrauen, und eine größere Folgestudie bestätigte es nicht.

In detail

Wirth et al. (2018, Cortex) führten einen Phase-IIa-Pilotversuch mit 30 kognitiv intakten älteren Erwachsenen mit subjektivem kognitivem Abbau durch, unter Verwendung eines spermidinreichen Pflanzenextrakts über drei Monate. Mnemonische Diskriminierung verbesserte sich in der Spermidingruppe mit einer mittleren Effektgröße (Cohen's d etwa 0.77), obwohl die Konfidenzintervalle weit waren und null erreichten. Die Autoren rahmten es als zu validierendes Signal ein, das die größere SmartAge-Studie an ihrem primären Endpunkt dann nicht bestätigen konnte.

The study · 1

Wirth et al., The effect of spermidine on memory performance in older adults at risk for dementia: a randomized controlled trial · Cortex 2018;109:181-188

Longevity And Mortality

Spermidin verlängert die Lebensdauer in Hefe, Fliegen, Würmern und MäusenPreliminary

In plain terms

Spermidin zu füttern hilft Hefe, Fliegen, Würmern und Mäusen, länger zu leben. Dies ist ein Tierergebnis und wurde nicht gezeigt, Menschen länger leben zu lassen.

In detail

Lebensdauerverlängerung durch Spermidin wurde zuerst in Hefe, Fliegen und Würmern berichtet (Eisenberg et al. 2009) und auf Säugetiere von Eisenberg et al. (2016, Nature Medicine) ausgedehnt, wo orales Spermidin das Überleben von Mäusen erhöhte und mit verbesserter Autophagie und Mitophagie verbunden war. Viele Interventionen verlängern die Lebensdauer von Nagetieren und Wirbellosen, ohne sich jemals beim Menschen zu replizieren.

The studies · 2

Eisenberg et al., Induction of autophagy by spermidine promotes longevity · Nat Cell Biol 2009;11(11):1305-1314

Eisenberg et al., Cardioprotection and lifespan extension by the natural polyamine spermidine · Nat Med 2016;22(12):1428-1438

Counts once: this finding and 1 other here come from the same source, so they are one body of evidence, not separate confirmations.

Höhere Nahrungsspermidinaufnahme ist mit niedrigerer Sterblichkeit verbunden, Hazard Ratio 0.76 pro Standardabweichung (Beobachtungsstudie)Preliminary

In plain terms

Erwachsene, die mehr spermidinreiche Lebensmittel aßen, starben über 20 Jahre mit niedrigeren Raten, und die Lücke zwischen dem höchsten und niedrigsten Konsum war etwa so groß wie einige Jahre jünger zu sein. Dies ist ein beobachtetes Muster, kein Beweis, dass Spermidin es verursacht hat.

In detail

Kiechl et al. (2018, American Journal of Clinical Nutrition) verfolgten 829 Teilnehmer der Bruneck-Studie (Alter 45-84 Jahre, 49.9 % männlich) mit wiederholten validierten Ernährungshäufigkeitsfragebögen; 341 Todesfälle traten über 20 Jahre auf. Die alters-, geschlechts- und kalorienangepasste Hazard Ratio für Gesamtmortalität pro 1-SD höherer Spermidinaufnahme betrug 0.74 (95-%-KI 0.66-0.83) und 0.76 (0.67-0.86) nach weiterer Anpassung für Lebensstil und andere Ernährungsfaktoren. Der Befund wurde unabhängig in der SAPHIR-Kohorte reproduziert.

The study · 1

Kiechl et al., Higher spermidine intake is linked to lower mortality: a prospective population-based study · Am J Clin Nutr 2018;108(2):371-380

Heart And Vascular

Bei alten Mäusen reduziert Spermidin Herzversteifung und verbessert die diastolische FunktionPreliminary

In plain terms

Bei alten Mäusen bewahrte Spermidin das Herz vor Versteifung und half ihm, sich zwischen den Schlägen richtig zu entspannen. Dies ist ein Tierbefund, kein nachgewiesener Effekt auf menschliche Herzen.

In detail

Eisenberg et al. (2016, Nature Medicine) berichteten, dass orales Spermidin bei alten Mäusen linksventrikuläre Hypertrophie und myokardiale Steifigkeit reduzierte und die diastolische Funktion verbesserte, mit parallelen Verbesserungen der Mitochondrienfunktion und Autophagie. Die Arbeit enthielt auch menschliche Beobachtungsdaten, die höhere Nahrungsspermidinaufnahme mit niedrigerem Blutdruck und kardiovaskulären Ereignissen verbanden, was hypothesegenerierend ist, nicht bestätigend.

The study · 1

Eisenberg et al., Cardioprotection and lifespan extension by the natural polyamine spermidine · Nat Med 2016;22(12):1428-1438

Counts once: this finding and 1 other here come from the same source, so they are one body of evidence, not separate confirmations.

How It Works

Anatomy of the Practice

1Inside the cell

Spermidine blocks an enzyme that adds acetyl tags to proteins. That block, plus a few related effects, switches on autophagy, the process a cell uses to break down and recycle its own worn-out proteins and organelles. Fasting and calorie restriction switch on the same process. Spermidine reproduces part of that effect.

2What autophagy clears

Worn-out mitochondria, misfolded proteins and other debris build up inside cells as the body ages. Autophagy clears them. Turning up autophagy is the mechanism behind every laboratory result for spermidine.

3From cell to person

A compound can switch on a good process in a dish and in a mouse and still not change how long or how well a person lives. Human aging is slow and has many causes. That gap is why the mechanism is settled while the human benefit is not.

The supplements tested in people deliver about 1 mg a day. An ordinary mixed diet supplies several times that, so the trials may have added little. You can read more about the autophagy process and the wider science of biological aging in the science library. The food-first case sits on the whole foods page, alongside autophagy itself.

Getting It Right

Ways to Do It

The mortality signal comes from food, and food supplies more spermidine than the trial supplements did.

1

Eat the foods that carry itFreeEasy

Wheat germ is the richest common source. Whole grains, legumes and peas add more, as do mushrooms, aged cheese and fermented foods such as natto. This is the food pattern that tracked with lower mortality in the observational data, and it overlaps almost entirely with a plain whole-food diet worth eating for many other reasons.

2

A spoon of wheat germ$Easy

If you want to raise intake deliberately, a tablespoon or two of plain wheat germ stirred into yogurt, oatmeal or a smoothie is the cheapest concentrated food source there is. It keeps in the fridge once opened and delivers spermidine alongside fiber, B vitamins and vitamin E.

3

A standardized wheat germ extract supplement$ to $$Easy

The supplements studied in people are wheat germ extracts standardized for spermidine, at roughly 1 to 6 mg a day. The one larger trial of such a product found no effect on its primary memory measure. Check for an independent testing mark, since supplements are loosely regulated.

Go Deeper

• Autophagy: what spermidine switches on, why it matters in aging, and what does and does not raise it.
• Biological aging: the wider science of how the body ages, and the levers with human evidence behind them.
• Whole foods: the food-first case; the spermidine-rich grains and legumes here are one part of it.

Cautions For This Practice

Extra restraint

Everything to be aware of is here, in one place. This practice suits most healthy people; a few situations call for real care.

Eine dreimonatige Studie fand das Weizenkeimextrakt-Supplement gut verträglich, Nebenwirkungen wie Placebo

Schwarz et al. (2018, Aging) testeten die Sicherheit und Verträglichkeit eines Weizenkeimextrakt-Spermidin-Supplements bei Mäusen und bei älteren Erwachsenen mit subjektivem kognitivem Abbau über drei Monate. Im menschlichen Arm wurde das Supplement gut vertragen, unerwünschte Ereignisse waren gegenüber Placebo ausgeglichen, und es gab keine klinisch relevanten Veränderungen bei Sicherheitslabormesswerten. Die bisherigen Studien sind kurz und moderat groß, sodass die Langzeitsicherheit chronischer Supplementierung nicht belegt ist.Schwarz et al., Safety and tolerability of spermidine supplementation in mice and older adults with subjective cognitive decline

The longevity claim is animal and observational, so treat anti-aging use as experimental

The lifespan results are in animals. The human mortality link is observational, drawn from food records in people who also ate and lived well. Anyone taking the compound to slow their own aging is running a personal experiment whose effect no human trial has measured. Exercise, sleep and diet have stronger human evidence for aging than any supplement.

The larger memory trial found no effect on its main measure

The SmartAge trial gave 100 older adults a wheat germ spermidine supplement for a year and found no change in memory.

Weigh who ran the trials

Several of the human supplement studies were designed or funded with involvement from a company that sells spermidine products, and some authors hold related patents or equity. That does not make the results wrong, and the studies disclosed it. But it is a reason to read the supplement claims with the source in mind, and to lean on the independent dietary and mechanistic work.

The usual source is wheat germ, which contains gluten

Most spermidine supplements are extracted from wheat germ, and wheat germ contains gluten. If you have celiac disease or a wheat allergy, a wheat germ product is not for you; look for a certified gluten-free source or get spermidine from tolerated foods instead. This is easy to miss because spermidine itself is marketed as a pure compound.

Pregnancy, breastfeeding, active cancer, and children: check first

Supplemental spermidine above food levels has not been studied in pregnancy, breastfeeding or childhood, so food-level intake is the sensible ceiling there. Polyamines including spermidine support cell growth, and levels run high in some tumors, so anyone with an active cancer should raise supplemental use with their oncology team before starting. Food intake as part of a normal diet is a separate matter and is not the concern here.

Start slow, be smart, read the research, and consult a professional if you have any concerns. This is here to inform your choice, not make it for you.

Common Questions

Does spermidine actually slow aging or extend life?

Not that any human trial has shown. In animals, spermidine switches on autophagy and extends lifespan, and that mechanism is well characterized. In people, the strongest signal is observational. In a cohort of 829 adults followed twenty years, higher dietary spermidine tracked with lower mortality. That worked out to a hazard ratio near 0.76 per standard deviation of intake, and a gap between the highest and lowest intakes comparable to being 5.7 years younger. It is an association in people who also tend to eat well and take care of themselves, so the healthier diet may explain the lower mortality on its own.

Should I eat spermidine foods or take a supplement?

For most people, eat the foods. The observational link to lower mortality comes from diet, and a normal diet already provides more spermidine than the supplement trials added. Wheat germ carries the most, with legumes, mushrooms, aged cheese and natto behind it. A wheat germ extract supplement delivers the isolated compound.

Does spermidine improve memory?

The only adequately powered trial found no benefit at the dose it used. A small pilot in 30 older adults hinted at a memory benefit earlier. That pilot also provided the short-term safety data, so both signals came from one small group. The SmartAge trial then gave 100 older adults with memory complaints a wheat germ spermidine supplement at 0.9 mg a day for a year. It showed no benefit on the primary memory outcome. Exploratory analyses raised the possibility of effects on verbal memory and inflammation. The authors said those would need a higher dose and a further trial to confirm.

Is spermidine safe to take?

In short trials at these doses it was well tolerated, with side effects no different from placebo. Pregnancy and breastfeeding, active cancer, and the gluten in wheat-germ products are the exceptions covered in the cautions above. For other adults at food levels or the 1-to-6-mg supplement doses studied, spermidine's short-term safety record is reassuring.