Spermidine and longevity

Spermidine is a tiny 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, which is where the awkward name comes from. The biology is what matters here, not the etymology.

So why do researchers care? One word: autophagy (your cells' built-in recycling program for damaged proteins and worn-out parts). Want the full mechanism story? See our autophagy guide. Here is the short version. Autophagy slows down as you age. Junk proteins pile up. Cells work less well. And almost everything that extends life in animals, from eating less to rapamycin to exercise, flips autophagy back on. Spermidine does the same thing.

The paper that started it all landed in 2009. A Graz-led team showed in Nature Cell Biology that spermidine made yeast, worms and flies live longer. The catch: it only worked when the autophagy genes were intact ^[1]. Seven years on, the same group went bigger. In Nature Medicine they put spermidine in mouse drinking water, and the mice lived longer and had healthier hearts in old age. Switch off autophagy, and the benefit vanished ^[2]. That same 2016 paper found a matching pattern in 829 people from the Bruneck cohort: the ones eating more spermidine had lower blood pressure, fewer cases of cardiovascular disease, and roughly 40 percent lower risk of dying from heart failure ^[2].

The link to dying from any cause showed up two years later. A 2018 analysis added longer follow-up and checked the signal again in a second cohort near Salzburg ^[4]. Then a newer paper from the Graz group, again in Nature Cell Biology, found something neat: fasting itself pushes up spermidine inside cells, and it does this across yeast, flies, mice and human volunteers ^[10]. Block the polyamine pathway and fasting stops extending lifespan. Put simply, spermidine looks like one of the molecules that delivers the payoff of eating less.

One honest caveat before you get excited. Nearly all of this is animal and cell biology. The mouse results are solid. But whether they carry over cleanly to people is a separate question, and the human data gets messier, as you will see below.

Spermidine is one of the few longevity compounds whose research heartland sits in the German-speaking world. Most of the groundwork comes from the Frank Madeo lab at the University of Graz in Austria, with the key human signal from the Italian-South-Tyrolean Bruneck cohort. That concentration is a quirk most people miss, and it is worth knowing because it shapes how much independent replication exists. The Graz work runs with Karl Franzens University and BioTechMed-Graz. The 2009 yeast paper, the 2016 Nature Medicine mouse study, the 2018 Science review, the SmartAge trial protocol with Charite Berlin, the 2024 Nature Cell Biology fasting paper: they all trace back to this Graz axis.

Two things follow from that. First, the Bruneck cohort that tied dietary spermidine to lower mortality is Italian-South-Tyrolean, a German-speaking corner of northern Italy. Second, the only spermidine ingredient with EU Novel Food approval, a wheat germ extract, comes from Longevity Labs+, a spin-off based in Graz, Austria. They sell it under the brand spermidineLIFE.

None of this means the science is settled. None of it means the Austrian product is automatically your best buy. It just means that when you open a recent peer-reviewed spermidine paper, the odds are good that Frank Madeo is on the author list. Knowing where research comes from helps you read it honestly. The Madeo group has been open about its funding, and several human studies got partial backing from Longevity Labs. That is a normal academic-industry tie, not a scandal. But it is context worth carrying with you.

Two other DACH centers have run human spermidine trials: the Vienna University of Applied Sciences (Pekar group, Wiener Neustadt) and Charite Berlin / DZNE Berlin (Wirth, Schwarz, Floeel). Together with Graz, those three labs make up almost the entire clinical evidence base.

Human evidence splits in two and points in two directions. Observational cohorts link a high-spermidine diet to lower death rates: in the Bruneck Study the highest intake group had roughly 15 to 25 percent lower all-cause mortality (HR 0.74 per 1-SD) ^[4]. But the best randomized trial, SmartAge, was NEGATIVE: 12 months of supplements did nothing for memory ^[8]. So the diet signal is encouraging while the one strong RCT is not. Let me walk you through both.

What we learn from watching people eat.

The Bruneck Study tracked 829 adults aged 45 to 84 in northern Italy from 1995 to 2015 ^[4]. Researchers used food questionnaires to estimate how much spermidine each person ate. The people eating the most (top third vs. bottom third) had roughly 15 to 25 percent lower risk of dying from any cause. And that held up even after the math accounted for age, smoking, BMI, calorie intake, physical activity and more. The standout numbers:

• Death from any cause, per 1-SD more spermidine in the diet: HR 0.74 (95% CI 0.66 to 0.83). In age-stratified terms, that is about like looking ~5.7 years younger.
• The same pattern showed up again on its own in the Salzburg-area SAPHIR cohort: HR 0.71 per 1-SD.

That is a real signal, and an impressive one. But it is still just observation. People who eat lots of spermidine also eat lots of whole grains, legumes and aged cheese. They eat Mediterranean-style. So was it the spermidine doing the work, or was spermidine just a tag-along marker for a healthy diet? Watching people eat cannot answer that.

What we learn from controlled trials.

The biggest randomized trial so far is SmartAge, published in JAMA Network Open in 2022 ^[8]. A hundred older adults with subjective cognitive decline took spermidine-rich wheat germ extract (about 0.9 mg spermidine per day) or a placebo for 12 months. The main thing they measured was memory, using a Mnemonic Similarity Task. The result: SmartAge was NEGATIVE on its main goal. No measurable boost to memory. None to blood biomarkers. None on brain MRI. And none on most of the secondary measures either.

An earlier, smaller pilot in Cortex had looked mildly promising: 30 people over three months, with a medium-sized effect on memory discrimination ^[5]. The bigger, longer SmartAge trial could not repeat it. That is exactly how science is supposed to run. Small positive pilot, then a larger trial to see if it holds. Here, it did not.

The signal pointing the other way.

A 2020 paper in Wiener Klinische Wochenschrift ran a three-month double-blind pilot across six nursing homes in Styria, Austria, with 85 older people aged 60 to 96 who had mild to moderate dementia. The group on the higher dose (about 3.3 mg/day spermidine) did a bit better on cognitive testing: a reported +2.23-point gain on the MMSE (a common dementia screening test) in the mild-dementia subgroup, with p = 0.026 in the full-text subgroup analysis ^[7]. The caveats are big, though. There was no true placebo arm, since both groups got spermidine, just at different doses. The sample was small. And these were people with established dementia, not the worried-but-healthy folks in SmartAge. So it does not cancel out SmartAge. It is just one reason the door on cognitive benefit is not fully shut.

The honest read. For cognition in healthy older adults at risk for dementia, the best trial we have says no benefit. For heart-related mortality in observational cohorts, the signal is consistent. The mechanism (autophagy) is plausible. None of that tells you to take spermidine or to avoid it. It is simply where the evidence stands in 2026.

The richest common food source of spermidine is wheat germ, at roughly 25 to 35 mg per 100 g, followed by soybeans, mushrooms, green peas, white beans and aged cheese. A normal mixed European diet delivers about 5 to 15 mg per day, so people were eating it long before anyone pressed it into a pill. The most thorough peer-reviewed food database we have is a 2019 polyamine survey in Frontiers in Nutrition ^[9]. The numbers below come from that paper, plus a few values from the wider literature. Heads up: they swing a lot with variety, ripeness, processing and storage. Treat them as ballpark figures, not lab-precise 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 sensible mixed European diet gives you somewhere between 5 and 15 mg of spermidine per day. The top third of the Bruneck cohort landed around 12 mg/day. Eat Mediterranean-style, with whole grains, legumes, vegetables and a bit of aged cheese, and you hit that range without even trying.

Want the densest real food? It is wheat germ, hands down. One tablespoon (about 7 g) of toasted wheat germ gives you roughly 2 mg of spermidine, the same ballpark as a typical supplement capsule. It costs a few euros per kilogram at any DACH supermarket. Stir it into yogurt, muesli, smoothies or bread.

One more wrinkle. Your gut bacteria make spermidine too. A decent chunk of the spermidine in your body never came from food at all. That is part of why the dose-response picture from supplements alone stays fuzzy: you are stacking a capsule on top of a personal baseline that swings a lot from person to person.

The only spermidine supplement legally real in the EU is spermidine-rich wheat germ extract from Triticum aestivum, capped at the equivalent of 6 mg spermidine per day for adults under EU Novel Food rules ^[12]. There is no approved EU health claim, and synthetic spermidine is not authorized. Anything else is either a compliant wheat germ product or a legal gray zone. This section is vendor-neutral on purpose. You are an adult, you can shop where you like. Our job is just to lay out the legal status and the evidence so you can decide.

The EU Novel Food rule. In the EU, any food ingredient that nobody ate in real amounts before 1997 counts as a Novel Food under Regulation (EU) 2015/2283, and it needs explicit approval before it can be sold. One spermidine ingredient has that approval: spermidine-rich wheat germ extract from Triticum aestivum, originally developed by Longevity Labs+ (Graz, Austria). The European Commission approved it via Implementing Regulation (EU) 2017/2470, then tweaked the specifications with Commission Implementing Regulation (EU) 2020/443 on 25 March 2020, after EFSA (the EU food-safety agency) checked it as a Novel Food ^[12]. The official list caps a food supplement for adults at the equivalent of 6 mg of spermidine per day, and it leaves out pregnant and breastfeeding women ^[12]. Supplement labels in Germany, Austria and Switzerland have to match those specs.

No approved health claim. Let me be blunt: there is no approved EU health claim for spermidine. The closest anyone got was a 2011 EFSA review of a proposed claim that spermidine keeps hair in its growth phase. EFSA looked at the evidence, found it too thin, and the claim was NOT approved ^[11]. So any marketing hinting that spermidine prevents disease, extends your life or regrows hair is running ahead of what regulators have actually signed off.

What this means when you shop. A spermidine supplement sold legally in Germany, Austria or Switzerland does one of three things. It uses the approved Longevity Labs+ wheat germ extract. Or it uses a different wheat germ extract that still fits the Novel Food approval. Or it sits in a legal gray zone, sometimes sold across borders or labeled as a plain 'wheat germ' product that does not openly advertise its spermidine. Pure synthetic spermidine, by the way, is not approved as an EU food supplement.

Which doses are actually backed by trials? The 2018 Wirth pilot used about 1.2 mg/day ^[5]. SmartAge used about 0.9 mg/day for 12 months ^[8]. The 2020 nursing-home trial used about 1.9 to 3.3 mg/day for three months ^[7]. The Bruneck cohort thirds spanned roughly 6 to 12 mg/day, all from food. Most approved supplements give you somewhere in the 1 to 3 mg/day range per serving. That sits inside the studied band, but at the low end of the dietary cohort signal.

Now, the money. A month's supply of an EU-approved spermidine wheat germ supplement in DACH usually runs 30 to 70 euros, with some country wobble (Switzerland tends to be priciest, Austria often cheapest since the maker is right there). A bag of plain wheat germ at the same supermarket costs about 3 to 5 euros and lasts a month at one tablespoon a day. The supplement gives you a measured, standardized dose. The wheat germ gives you that dose plus fiber, magnesium, vitamin E, B vitamins and zinc. Neither choice is wrong. They are just different products.

What we honestly cannot tell you. Whether brand A beats brand B. Whether a higher-dose unapproved import is safer or more effective than the EU-approved one (it is not generally safer, just less regulated). Whether timing matters. Whether spermidine works better paired with fasting (the 2024 fasting paper makes that plausible on paper ^[10], but no published human trial has tested it). These are open questions. Use this guide to ask sharper ones at your Hausarzt, Wahlarzt or Privatarzt appointment, especially if you have a chronic condition or take medication.

Short answer. Spermidine is already in everyone's normal diet. At the doses EU-approved supplements give you (about 1 to 6 mg/day), the safety record so far looks reassuring. It is also limited, which matters just as much.

A 2018 safety paper in Aging pooled animal and human data and found no clinically meaningful red flags for spermidine-rich wheat germ extract over three months in older adults ^[6]. The 12-month SmartAge trial also reported no serious side effects tied to the supplement ^[8]. And the EU Novel Food approval caps daily intake for adults and keeps certain groups out of the approved use.

Where to be careful.

• Pregnancy and breastfeeding. The EU Novel Food approval for spermidine-rich wheat germ extract leaves out pregnant and breastfeeding women. Not because harm turned up, but because nobody has established safety for that group. Pregnant or breastfeeding? Stick to food sources.
• Children. Same reasoning. The approval does not cover kids. Spermidine from food is fine. Concentrated capsules are not the right call.
• Active or recently treated cancer. This is the trickiest question in the whole field. Spermidine drives autophagy, and autophagy can either protect you or feed tumor growth, depending on the cancer type and stage. The 2018 safety paper points out that in mouse studies, a lifetime of dietary spermidine did not raise how often tumors appeared, and in some chemically triggered liver cancer models it was actually protective ^[6]. But the human evidence in active cancer patients is basically zero, and Madeo's own group cautions that polyamine-driven autophagy could, in principle, prop up tumors that already exist. If you have active or recently treated cancer, do not start a spermidine supplement without your oncologist's input.
• It comes from wheat germ. Spermidine supplements made from wheat germ contain gluten, even if only a trace. If you have celiac disease or non-celiac gluten sensitivity, pick a certified gluten-free product or skip the supplement.
• Drug interactions. No major direct drug interactions are on record at the studied supplement doses. That is not the same as saying none exist. If you take immunosuppressants, cancer drugs or strong autophagy modulators (rapamycin, high-dose metformin, hydroxychloroquine), have that conversation with your Hausarzt or Wahlarzt before adding spermidine.

What we still do not know.

• Whether taking it for decades is safe. The longest human trial ran 12 months.
• Whether it prevents dementia in people with no symptoms yet (SmartAge enrolled people with subjective cognitive decline, not unaffected adults).
• Whether the heart-related signal from cohorts holds up in a randomized prevention trial.
• Whether spermidine plus fasting, exercise or rapamycin adds up to extra benefit in people (the 2024 fasting paper makes the fasting combo biologically plausible ^[10]).

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