Autophagy is literally “self-eating” in Greek, and the discovery of its mechanisms was awarded the Nobel Prize in 2016. Spermidine, one of the polyamines studied in this context, naturally occurs in fermented soy, including our natto. Here I have gathered what is known for certain about both concepts: where their names come from and what studies actually show, and what cannot be directly concluded from them.
⚠️ Are you taking anticoagulant medication (for example acenocoumarol or warfarin)? Natto is one of the richest natural sources of vitamin K, which may affect how these medicines work. Consult your diet and supplements with a doctor. See the important legal and medical information.
In short
- Spermidine is a polyamine present in all living cells, naturally occurring in, among others, fermented soy, wheat germ, and aged cheeses.
- Autophagy is the cellular process of breaking down and recycling worn-out cell components, whose mechanisms were described by Yoshinori Ohsumi, who was awarded the Nobel Prize for it in 2016.
- Data on the effect of spermidine on autophagy comes mainly from in vitro studies and animal models, not from clinical trials in humans.
- In the European Union, spermidine has no authorised health claim (Regulation (EC) 1924/2006), which is why we describe it from the perspective of biology and nomenclature, not a promised effect.
- Natto, as fermented soy, is one of the natural sources of spermidine.
The origin of the name spermidine
Spermidine belongs to the polyamines, a small group of nitrogen compounds present in every cell, from bacteria to humans. This whole family of compounds (alongside spermidine, it also includes spermine) owes its name to semen (Latin: sperma), because that is where they were first noticed. Today it is known that polyamines have nothing to do exclusively with reproduction: they are needed by every dividing cell, so they also occur in plants, fungi, and fermented products, including our natto.
What autophagy is and where the name comes from
“Autophagy” is a Greek compound: “auto” means self, and “phagein” means to eat. The name describes the mechanism well: a cell breaks down its own worn-out or damaged components (proteins, organelles) and reuses them, rather than simply accumulating them. This is a fundamental process of cell biology, known for decades, but its molecular mechanisms were first described by the Japanese biologist Yoshinori Ohsumi, who received the Nobel Prize in Physiology or Medicine for this in 2016. This is recognition for a discovery in basic cell biology, not confirmation of the action of any supplement or dietary ingredient.
What research on spermidine and autophagy describes
In the scientific literature, spermidine is described as a compound that under laboratory conditions may influence the intensity of autophagy. These observations come primarily from in vitro studies (on cell cultures) and from studies in animal models. Results obtained in a test tube and in animals do not automatically translate into effects in humans after oral intake, and clinical trials involving humans are few and have varied results.
Autophagy, longevity, and what we do not promise
It is worth separating two things that are easy to confuse. The fact that the mechanisms of autophagy exist and have been scientifically described is a fact, confirmed by the Nobel Prize for Ohsumi. Quite a different matter is whether the consumption of spermidine from the diet extends human life, for which clinical evidence is still lacking, and the available data comes mainly from animal models. We do not attribute to our natto or the spermidine it contains any life-extending action or the “activation” of autophagy. What is certain is only that spermidine naturally occurs in fermented soy, from which we make our natto.
Natural sources of spermidine
Spermidine can be found in many foods:
- natto and other fermented soy products,
- wheat germ,
- aged cheeses,
- mushrooms,
- legumes.
Spermidine in our natto
Spermidine is a natural component of fermented soy, so you will find it in all our natto. Fresh natto has the most to say about it, because it is simply soy right after fermentation, without further processing. We produce it in Zielona Góra from certified organic soy.
See our fresh natto in the shop
Safety and precautions
Natto is a food product safe for most healthy people. Due to its vitamin K2 content, people taking anticoagulant medication (for example vitamin K antagonists, such as warfarin or acenocoumarol) should consult a doctor before consumption. Natto contains soy, so it is not intended for people with soy allergy. Pregnant and breastfeeding women and people taking regular medication should ask a doctor before adding new products to their diet. A food supplement and no food product replaces a varied diet and healthy lifestyle.
Summary
Spermidine is a polyamine present in many foods, including our natto, and its name traces to semen, where this group of compounds was first noticed. Autophagy is a scientifically described, Nobel Prize-winning process of cellular “clean-up.” Data on the effect of spermidine on autophagy comes mainly from laboratory and animal studies, and conclusions about human lifespan cannot yet be drawn from them. Natto is best treated as part of a varied diet, not as a promise of a longer life.
Frequently asked questions
What exactly does the word “autophagy” mean?
It is a Greek compound: “auto” means self, and “phagein” means to eat, so literally “self-eating.” The name describes the process by which a cell breaks down and reuses its own worn-out components.
Where does the name spermidine come from?
Spermidine belongs to the polyamines, a family of compounds named after semen (Latin: sperma), where they were first observed. Today it is known that they occur in every cell, including plant and fungal cells.
Does spermidine extend life?
There is no clinical evidence for this in humans. Available data comes mainly from in vitro studies and animal models, and the 2016 Nobel Prize concerned the discovery of the mechanisms of autophagy as a biological phenomenon, not confirmation of an anti-ageing effect in humans.
Does spermidine have a confirmed health effect in the European Union?
No. Spermidine has no authorised health claim in the European Union, which is why a reliable description is limited to its structure, origin, and what has been measured in studies, not to its action.
Who should exercise caution with natto consumption?
Caution and consultation with a doctor are advisable when taking anticoagulant medication, due to the vitamin K2 content. Natto contains soy, so it is not suitable for people with soy allergy.
Sources
- Regulation (EC) No 1924/2006 on nutrition and health claims made on foods, text on EUR-Lex
- The Nobel Prize in Physiology or Medicine 2016, Yoshinori Ohsumi, „for his discoveries of mechanisms for autophagy”, NobelPrize.org
Legal and medical note. This article is educational and does not replace the advice of a doctor or pharmacist. The substances described here have no authorised health claims in the European Union (Regulation (EC) 1924/2006), and a food supplement is not a medicine and does not replace a varied diet. Full information is on the Legal and medical information page.
