Spermidine content of selected dietary supplements: potential for improvement?

Dietary spermidine is emerging as a substance with promising health-promoting and healthy ageing-promoting properties. Its autophagy-inducing potential has been especially well-documented. This process is suspected to be at the root of the life-prolonging effects of fasting and in-vivo spermidine supplementation. In humans, high dietary spermidine intake is associated with a lifespan increase of 5.7 years. Numerous studies provide indications of its effects on the cardiovascular, nervous, and immune systems as well as on the formation and development of tumors. Nevertheless, no health claims are currently authorized in the EU for spermidine or spermidine-rich functional foods. When ingested through food or dietary supplements, dosage appears to play an important role in replicating the favorable effects. Currently, there are ongoing proceedings regarding the novelty of a certain manufacturing process of spermidine supplements, but many other plant extracts with high spermidine content from different sources are marketed without the need for novel food authorization.  This article discusses the varying test results obtained for the spermidine concentration of popular spermidine supplements. Soybean extract seems to be slightly superior in terms of spermidine concentration, but one wheat germ-based product stood out in this analysis due to a 10 times higher spermidine concentration than comparable products.Keywords: spermidine, food supplements, novel food, botanicals, functional foods, autophagy, spermidine-rich wheat germ extract