Supplement: Spermidine

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

Spermidine switches on autophagy, and blocking autophagy removes its lifespan benefitModerate · mixed

In plain terms

Spermidine switches on autophagy, the process a cell uses to clear out and recycle its own worn-out parts, and that switch is what lets it extend life in simple laboratory organisms. When researchers block autophagy, the life-extending effect goes away.

In detail

Eisenberg et al. (2009, Nature Cell Biology) showed that spermidine inhibits histone acetyltransferase activity, triggers autophagy, and extends lifespan in yeast, flies, worms and human immune cells in culture. Genetic or pharmacological blockade of autophagy abolished the lifespan benefit, establishing autophagy as the mediating mechanism, not a correlate. This is the well-characterized mechanistic basis for interest in spermidine.

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

Geen geheugenvoordeel van 0.9 mg/dag spermidine over een jaar bij 100 oudere volwassenenModerate · no effect

In plain terms

In de tot nu toe grootste studie deden oudere volwassenen met geheugenklachten die een jaar lang dagelijks een tarwekiemspermidinesupplement namen, het op de belangrijkste geheugentest niet beter dan degenen die een placebo namen.

In detail

De SmartAge-studie (Schwarz en collega's, 2022, JAMA Network Open) randomiseerde 100 volwassenen van 60-90 jaar (49% vrouw) naar 0.9 mg/dag spermidine uit tarwekiemen of placebo gedurende 12 maanden. De primaire uitkomst, mnemonische discriminatie op de Mnemonic Similarity Task, liet geen verschil tussen de groepen zien (-0.03; 95%-BI -0.11 tot 0.05; P = 0.47), en de secundaire uitkomsten bleven ongewijzigd. Verkenningsanalyses wekten mogelijke effecten op verbaal geheugen en ontsteking die de auteurs zeiden bevestiging nodig te hebben bij hogere doses.

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

Een pilotstudie bij 30 mensen wees op een geheugenwinst (Cohen's d 0.77) die de grotere studie niet bevestigdePreliminary

In plain terms

Een kleine studie van drie maanden bij 30 oudere volwassenen gaf een hint dat een spermidinesupplement het geheugen een beetje hielp. De studie was te klein om op te vertrouwen en een grotere vervolgsstudie bevestigde het niet.

In detail

Wirth en collega's (2018, Cortex) voerden een fase-IIa-pilotstudie uit bij 30 cognitief intacte oudere volwassenen met subjectieve cognitieve achteruitgang, met een spermidinerijke plantenextract gedurende drie maanden. De mnemonische discriminatie verbeterde in de spermidinegroep met een middelgrote effectgrootte (Cohen's d van ongeveer 0.77), hoewel de betrouwbaarheidsintervallen breed waren en nul bereikten. De auteurs beschouwden het als een signaal dat gevalideerd moest worden, wat de grotere SmartAge-studie vervolgens niet wist te bevestigen op het primaire eindpunt.

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

Spermidine verlengt de levensduur bij gist, vliegen, wormen en muizenPreliminary

In plain terms

Feeding spermidine helps yeast, flies, worms and mice live longer. This is an animal result and has not been shown to make people live longer.

In detail

Levensduurverlenging door spermidine werd voor het eerst gerapporteerd bij gist, vliegen en wormen (Eisenberg en collega's, 2009) en uitgebreid naar zoogdieren door Eisenberg en collega's (2016, Nature Medicine), waarbij oraal spermidine de overleving bij muizen verhoogde en werd geassocieerd met verbeterde autofagie en mitofagie. Veel interventies verlengen de levensduur van knaagdieren en ongewervelde dieren zonder ooit bij mensen te worden gerepliceerd.

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.

Een hogere voedingsinname van spermidine gaat samen met lagere sterfte, hazard ratio 0.76 per standaarddeviatie (observationeel)Preliminary

In plain terms

Volwassenen die meer spermidinerijke voeding aten, stierven over 20 jaar met lagere percentages, en het verschil tussen de hoogste en laagste innames was ongeveer zo groot als een paar jaar jonger zijn. Dit is een waargenomen patroon, geen bewijs dat het spermidine dit veroorzaakte.

In detail

Kiechl en collega's (2018, American Journal of Clinical Nutrition) volgden 829 deelnemers in de Bruneck-studie (45-84 jaar, 49.9% man) met herhaalde gevalideerde voedselfrequentievragenlijsten; er vonden 341 sterfgevallen plaats over 20 jaar. De leeftijd-, geslacht- en calorie-gecorrigeerde hazard ratio voor sterfte door alle oorzaken per 1-SD hogere spermidine-inname was 0.74 (95%-BI 0.66-0.83), en 0.76 (0.67-0.86) na verdere correctie voor leefstijl en andere voedingsfactoren. De bevinding werd onafhankelijk gerepliceerd in het SAPHIR-cohort.

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

Bij oude muizen vermindert spermidine hartverstijving en verbetert de diastolische functiePreliminary

In plain terms

Bij oude muizen voorkwam spermidine dat het hart verstijfde en hielp het het hart goed te ontspannen tussen de slagen. Dit is een dierbevinding, geen aangetoond effect op mensenharten.

In detail

Eisenberg en collega's (2016, Nature Medicine) rapporteerden dat oraal spermidine bij oude muizen de linkerventrikelhypertrofie en myocardiale stijfheid verminderde en de diastolische functie verbeterde, met gelijklopende verbeteringen in mitochondriale functie en autofagie. Het artikel bevatte ook humane observationele gegevens die hogere voedingsinname van spermidine koppelden aan lagere bloeddruk en cardiovasculaire voorvallen, wat hypothesevormend is, niet bevestigend.

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.

Een studie van drie maanden vond het tarwekiemsupplement goed verdragen, bijwerkingen zoals placebo

Schwarz en collega's (2018, Aging) testten de veiligheid en verdraagbaarheid van een tarwekiemspermidinesupplement bij muizen en bij oudere volwassenen met subjectieve cognitieve achteruitgang gedurende drie maanden. Bij het menselijke deel werd het supplement goed verdragen, waren bijwerkingen gebalanceerd tegenover placebo, en waren er geen klinisch relevante veranderingen in veiligheidsparameters in het laboratorium. De tot nu toe uitgevoerde studies zijn kort en bescheiden van omvang, dus de veiligheid op lange termijn van chronische suppletie is niet vastgesteld.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.