Spermidine Simply Explained

1. What Is Spermidine?

Spermidine is a polyamine (a substance produced by the body). This group of substances occurs in the cells of humans, animals and plants. The body can produce spermidine itself. In addition, we take it in through the diet. In research, spermidine is studied mainly in connection with cellular self-cleaning (autophagy) and with aging.

2. Where Is It Found, and What Is It Made From?

Spermidine is found in almost all living cells. Wheat germ, aged cheese, fermented soy products and mushrooms are particularly well known. Legumes are also among the sources. For dietary supplements, spermidine is obtained, for example, from rice germ or produced as a pure substance. One such pure form is spermidine trihydrochloride.

3. What Does Spermidine Do? What Research Shows

Biological Aging

In a small placebo-controlled study, pure spermidine lowered markers of cell aging in immune cells in older adults 34. A combination preparation with spermidine and other substances lowered biological age as measured by immune functions 2. Another small study without a placebo group found more markers of cellular self-cleaning than at the start only with the higher amount of spermidine from rice germ extract 6. The studies are small and short, and some findings come from combination preparations 2. Observational data on spermidine intake through the diet must be considered separately from this and do not allow any statement about effects.

Cognition and Memory

A small pilot study in twelve healthy individuals compared two amounts of spermidine from rice germ extract without a placebo group. With the higher amount, the nerve growth factor BDNF in the blood increased compared with the baseline value 6. However, this laboratory value is not a measured memory test. It is only a single, very small study without independent confirmation. A cross-sectional study with spermidine levels in the blood without dietary supplementation even reports less favorable values for certain brain regions 14. Whether spermidine actually improves memory therefore remains open.

Heart and Circulation

There is no study with a placebo group on pure spermidine here. The existing small studies mainly investigated mixed preparations, that is, combinations with other substances. One study with such a mixed preparation showed better cholesterol levels in overweight older people 1. Another mixed preparation improved vascular function without changing blood pressure 8. In a study without a placebo group (sham), a higher amount of spermidine from rice germ extract reduced an inflammation marker and blood lipids compared with the baseline value 6. Because almost all preparations were mixtures, no result can be attributed to spermidine alone.

Muscles and Physical Performance

A small crossover study in five endurance athletes found lower markers of muscle damage compared with the baseline value after taking a mixture of spermidine and other substances 7. This is a single study with a very small number of participants in which the participants were not assigned by lot. In addition, it investigated a combination preparation, so the finding cannot be attributed to spermidine alone. Whether pure spermidine or a spermidine-rich diet influences muscles and performance still needs to be clarified.

Metabolism

Here there are only a few very small studies. All investigated combination preparations in which spermidine was combined with other substances. A study in overweight older adults with elevated long-term blood sugar found better fasting blood sugar levels for a combination preparation 1. A small preliminary study in endurance athletes found, after taking a mixture of spermidine, trehalose, nicotinamide and polyphenols, less oxidative stress and more favourable self-cleaning markers than at the start 7. The informative value is limited because the groups were very small and the participants in two studies were not assigned by lot. No result can be attributed to spermidine alone.

Other Investigations

In a placebo-controlled study, pure spermidine enhanced the antibody and memory cell response after a vaccination in older adults with a weak vaccine response 34. A study with a combination preparation found better appetite and satiety perception as well as less abdominal pain 1. Another study with a different combination preparation reported better immune function 2. High-dose pure spermidine did not change routine blood values in a placebo-controlled study in older men and was well tolerated 5. Overall, the groups are predominantly small, and some findings come from combination preparations.

4. How Was Spermidine Taken in the Studies?

Pure spermidine as a dietary supplement, spermidine from rice germ extract and combination preparations with other substances such as nicotinamide, trehalose or hesperidin were investigated. The amount taken differed considerably between the studies. Details are shown in the table.

5. Is Spermidine Safe? Side Effects in the Studies

Pure spermidine was well tolerated in two small placebo-controlled studies 35. In the study with high-dose spermidine trihydrochloride, no side effects occurred that were related to the preparation 5. A combination preparation did not differ from placebo in terms of side effects 1. Spermidine from rice germ extract showed unremarkable safety values in a small pilot study 6. Many studies were small, short or investigated combination preparations. Therefore, it cannot be said for every finding what share spermidine had in it.

All details with tables and sources: full expert page on Spermidine