Spermidine and longevity

Spermidine is a small molecule called a polyamine. Your body makes it, your gut bacteria make some of it, and you eat it too. Antonie van Leeuwenhoek first spotted it in human semen back in 1678. That is where the awkward name comes from. The biology, not the etymology, is what matters here.

Researchers care about spermidine for one main reason: autophagy (your cells' built-in recycling program for damaged proteins and worn-out organelles). For the full mechanism story, see our autophagy guide. Autophagy slows down as you age. Damaged proteins pile up. Cells work less well. Most things that extend lifespan in animals, from caloric restriction to rapamycin to exercise, switch autophagy back on. Spermidine does the same thing.

The headline paper landed in 2009. A Graz-led team (Eisenberg, Madeo and colleagues, Nature Cell Biology, 2009) showed that spermidine extended lifespan in yeast, worms and flies. The effect needed working autophagy genes. Seven years later the same group scaled it up. In Nature Medicine (Eisenberg et al., 2016), spermidine in drinking water extended median lifespan in mice and improved heart function in old animals. Block autophagy, and the benefit vanished. That paper also reported a parallel signal in 829 people from the Bruneck cohort: higher dietary spermidine tracked with lower blood pressure, lower cardiovascular disease incidence, and roughly 40 percent lower fatal heart-failure risk.

The all-cause mortality link came two years later, when Kiechl and colleagues (2018) added extended follow-up and validated the signal in a second Salzburg-area cohort. A more recent paper from the Graz group (Hofer et al., Nature Cell Biology, 2024) showed that fasting itself raises cellular spermidine across yeast, flies, mice and human volunteers. Block the polyamine pathway, and the lifespan benefit of fasting disappears. In other words, spermidine looks like one of the molecules that carries the benefits of caloric restriction.

One honest caveat. Nearly all of this is animal and cell biology. The mouse results hold up well. Whether they translate cleanly to humans is a separate question, and the human data is more mixed, as you will see below.

Spermidine is one of the few longevity compounds where the field's center of gravity sits in the German-speaking world. Most of the basic work comes from the Frank Madeo lab at the University of Graz in Austria, in collaboration with Karl Franzens University and BioTechMed-Graz. The 2009 yeast paper, the 2016 Nature Medicine mouse study, the 2018 Science review, the SmartAge clinical trial protocol with Charite Berlin, and the 2024 Nature Cell Biology fasting paper all run through this Graz axis.

Two practical points follow. First, the Bruneck cohort that linked dietary spermidine to lower mortality is Italian-South-Tyrolean, a German-speaking region in northern Italy. Second, the only spermidine ingredient with EU Novel Food authorization, a wheat germ extract, comes from Longevity Labs+, a spin-off based in Graz, Austria. The product is sold under the brand spermidineLIFE.

This does not mean the science is settled. It does not mean the Austrian product is automatically the best buy. It just means that if you read a recent peer-reviewed spermidine paper, there is a good chance Frank Madeo is on the author list. Knowing where the research comes from helps you read it honestly. The Madeo group has been open about its funding ties, but several human studies were partly supported by Longevity Labs. That is a normal academic-industry relationship, not a scandal. It is still context you should know.

The Vienna University of Applied Sciences (Pekar group, Wiener Neustadt) and the Charite Berlin / DZNE Berlin (Wirth, Schwarz, Floeel) are the other two DACH centers that have run human spermidine trials. Together with Graz, they account for almost all the clinical evidence base.

There are two strands of human evidence. They tell slightly different stories.

Observational cohorts.

The Bruneck Study (Kiechl, American Journal of Clinical Nutrition, 2018) followed 829 adults aged 45 to 84 in northern Italy from 1995 to 2015. Food frequency questionnaires estimated dietary spermidine. Higher intake (top tertile vs. lowest) tracked with roughly 15 to 25 percent lower all-cause mortality. The signal survived adjustment for age, smoking, BMI, calorie intake, physical activity and other variables. The headline numbers:

• All-cause mortality, per 1-SD higher spermidine intake: HR 0.74 (95% CI 0.66 to 0.83), about the same as looking ~5.7 years younger in age-stratified mortality
• Independent replication in the Salzburg-area SAPHIR cohort: HR 0.71 per 1-SD

This is a real and impressive observational signal. It is also still observational. People who eat a lot of spermidine eat a lot of whole grains, legumes and fermented cheese. They eat a Mediterranean-style diet. Whether spermidine itself did the work, or whether it is a marker for the underlying diet pattern, the cohort cannot answer.

Randomized trials.

The biggest RCT to date is SmartAge (Schwarz, JAMA Network Open, 2022). One hundred older adults with subjective cognitive decline got 12 months of spermidine-rich wheat germ extract (about 0.9 mg spermidine per day) or placebo. The primary endpoint was memory performance on a Mnemonic Similarity Task. SmartAge was NEGATIVE on the primary endpoint. No measurable benefit on memory, on blood biomarkers, on brain MRI, or on most secondary outcomes.

A smaller earlier pilot (Wirth, Cortex, 2018) had been mildly positive in 30 participants over three months, with a medium effect size on mnemonic discrimination. The larger and longer SmartAge trial did not replicate this. That is how science is supposed to work: small positive pilot, larger trial, see whether it survives. Here, it did not.

A counter-signal.

The Pekar group (Wiener Klinische Wochenschrift, 2020) ran a three-month double-blind multicenter pilot in 85 older adults aged 60 to 96 with mild to moderate dementia, across six nursing homes in Styria, Austria. The higher-dose group (about 3.3 mg/day spermidine) showed a small improvement on cognitive testing, with a reported +2.23-point MMSE gain in the mild-dementia subgroup (p = 0.026 in the full-text subgroup analysis). The trial had no true placebo arm (both arms received spermidine at different doses), the sample was small, and the population differed from SmartAge (established dementia vs. subjective decline). It does not undo SmartAge. It is one reason the field has not closed the book on cognitive benefit.

Honest reading. For cognition in healthy older adults at risk for dementia, the best-quality trial is negative. For cardiovascular mortality in observational cohorts, the signal is consistent. The mechanistic basis (autophagy) is plausible. None of this is a reason to take or avoid spermidine. It is the actual state of the evidence in 2026.

Long before anyone pressed spermidine into a pill, people ate it every day. The most thorough peer-reviewed food database is the polyamine survey from Munoz-Esparza and colleagues (Frontiers in Nutrition, 2019). The numbers below are converted from that paper, with a few values from the broader literature. They vary widely with variety, ripeness, processing and storage. Treat them as orders of magnitude, not lab readings.

Food	Approximate spermidine	Notes
Wheat germ (raw or toasted)	~25 to 35 mg/100 g	The single richest common food source
Soybeans (dried)	~15 to 20 mg/100 g	Plus tofu, natto, tempeh
Aged cheese (cheddar, parmesan, blue)	~1 to 2 mg/100 g	Younger cheeses much lower
Mushrooms	~3 to 9 mg/100 g	Higher in shiitake and oyster
Green peas	~5 to 7 mg/100 g	Fresh; canned slightly lower
Navy beans, white beans	~5 to 12 mg/100 g	Cooked from dry
Broccoli, cauliflower	~2 to 3 mg/100 g
Pears, apples	~0.5 to 1 mg/100 g
Whole grain bread	~0.5 to 1 mg/100 g

A reasonable mixed European diet provides somewhere between 5 and 15 mg of spermidine per day. The Bruneck cohort's highest tertile sat around 12 mg/day. Mediterranean-style eating, with whole grains, legumes, vegetables and some aged cheese, gets you there without trying.

If you want the densest real food, the answer is wheat germ. A tablespoon (about 7 g) of toasted wheat germ delivers roughly 2 mg of spermidine, the same range as a typical supplement capsule. It costs a few euros per kilogram at any DACH supermarket. It works in yogurt, muesli, smoothies and bread.

One more thing. Your gut bacteria also make spermidine. A meaningful share of the spermidine in your body never came from food at all. This is one reason the dose-response curve from supplements alone is murky: you are adding to a background that varies a lot between people.

This section is vendor-neutral on purpose. You are an adult, you can shop. Our job is to explain the regulatory and evidence picture.

EU Novel Food status. In the EU, any food ingredient not consumed in significant amounts before 1997 counts as a Novel Food under Regulation (EU) 2015/2283 and needs explicit authorization. Spermidine-rich wheat germ extract from Triticum aestivum, originally developed by Longevity Labs+ (Graz, Austria), is the one spermidine ingredient with EU authorization. The European Commission authorized it via Implementing Regulation (EU) 2017/2470, with the specifications amended by Commission Implementing Regulation (EU) 2020/443 (25 March 2020), following an EFSA Novel Food safety assessment. The Union list specification sets a maximum daily intake equivalent to 6 mg of spermidine for adult food supplements, excluding pregnant and lactating women. Food-supplement labels in DE, AT and CH have to match those specs.

No authorised health claim. Worth being blunt about: there is no authorised EU health claim for spermidine. The most relevant attempt was EFSA 2011, evaluating a proposed claim that spermidine maintains anagen-phase hair growth. EFSA found the evidence insufficient and the claim was NOT authorised. Any marketing that suggests spermidine prevents disease, extends lifespan or restores hair in humans is outrunning what regulators have signed off on.

Practical implications. A spermidine supplement legally sold in Germany, Austria or Switzerland either: (a) uses the authorized Longevity Labs+ wheat germ extract, (b) uses a different wheat germ extract that is also compliant with the Novel Food authorization, or (c) sits in a legal gray zone, sometimes sold cross-border or as a 'wheat germ' product that does not explicitly market the spermidine content. Pure synthetic spermidine is not authorized as an EU food supplement.

What concentrations are actually proven? The Wirth 2018 pilot used about 1.2 mg/day. SmartAge used about 0.9 mg/day for 12 months. The Pekar 2020 nursing-home trial used about 1.9 to 3.3 mg/day for three months. The Bruneck cohort tertiles spanned roughly 6 to 12 mg/day, all from food. Most authorized supplements deliver something in the 1 to 3 mg/day range per serving, which sits inside the studied band but at the low end of the dietary cohort signal.

A note on price. A monthly supply of an EU-authorized spermidine-rich wheat germ extract supplement in DACH typically costs 30 to 70 euros, with some variation by country (CH usually most expensive, AT often cheapest given proximity to the manufacturer). A bag of wheat germ at the same supermarket costs roughly 3 to 5 euros and lasts a month at one tablespoon per day. The supplement gives you a measured, standardized dose. The wheat germ gives you the dose plus fiber, magnesium, vitamin E, B vitamins, and zinc. Neither approach is wrong. They are different products.

What we cannot tell you. Whether brand A beats brand B. Whether a higher-dose unauthorized product from abroad is safer or more effective than the EU-authorized one (it is not generally safer, just less regulated). Whether timing matters. Whether spermidine works better with fasting (mechanistically plausible per Hofer 2024, not yet tested in a published human trial). These are open questions. Use this guide to ask better ones at your Hausarzt, Wahlarzt or Privatarzt appointment, especially if you have a chronic condition or take medication.

Short answer. Dietary spermidine is part of every human's normal diet. At the doses delivered by EU-authorized supplements (about 1 to 6 mg/day), the safety record so far is reassuring but limited.

A safety paper from Schwarz and colleagues (Aging, 2018) combined animal and human data and reported no clinically meaningful adverse signals for spermidine-rich wheat germ extract over three months in older adults. The 12-month SmartAge trial (Schwarz 2022) did not report serious adverse events linked to the intervention either. The EU Novel Food authorization sets limits on maximum daily intake for adults and excludes certain populations from authorized use.

Where caution is warranted.

• Pregnancy and lactation. EU Novel Food authorization for spermidine-rich wheat germ extract excludes pregnant and breastfeeding women. Not because harm has been shown, but because safety has not been established for that population. If you are pregnant or breastfeeding, food sources only.
• Children. Same logic. The authorization does not cover children. Spermidine from food is fine. Concentrated supplements are not appropriate.
• Active or recently treated cancer. This is the hardest question in the field. Spermidine drives autophagy, which can be either protective or growth-promoting depending on the tumor type and stage. Schwarz 2018 notes that in mouse studies, lifelong dietary spermidine did not raise tumor frequency, and in some chemically induced liver cancer models it was protective. But the human evidence in active cancer patients is essentially zero, and Madeo's own group warns that polyamine-driven autophagy could in principle support established tumors. If you have active or recently treated cancer, do not start a spermidine supplement without your oncologist's input.
• Wheat germ origin. Spermidine supplements made from wheat germ contain gluten, even if very low. People with celiac disease or non-celiac gluten sensitivity should choose a certified gluten-free preparation or skip the supplement entirely.
• Drug interactions. No major direct pharmacokinetic interactions are documented at studied food-supplement doses. That is not the same as 'no interactions exist'. If you take immunosuppressants, anticancer drugs or strong autophagy modulators (rapamycin, metformin at high dose, hydroxychloroquine), this is a conversation for your Hausarzt or Wahlarzt before adding spermidine.

What we still do not know.

• Whether decades of supplementation are safe. The longest human trial is 12 months.
• Whether spermidine prevents dementia in people who do not yet have symptoms (SmartAge enrolled subjective cognitive decline, not unaffected adults).
• Whether the cardiovascular signal from cohorts translates into a randomized prevention effect.
• Whether spermidine combined with fasting, exercise or rapamycin produces additive benefit in humans (Hofer 2024 makes the fasting combination biologically plausible).

For any health decision based on this guide, talk to your Hausarzt (Germany), Wahlarzt or Privatarzt (Austria) or Hausarzt / Spezialist (Switzerland). This guide is education, not a prescription.