NEW FINDINGS FROM CELL RESEARCH
Spermidine is essential for fasting-mediated autophagy and longevity
Who doesn’t dream of growing old in good health and staying fit and active for as long as possible? Scientists in the fields of longevity and healthy ageing have spent many years researching the measures, internal mechanisms and substances in the body that slow down the biological ageing process, prevent typical age-related diseases and enable us to live a long and healthy life. One substance produced by the body that is currently the subject of extensive research is spermidine. An article published in the renowned scientific journal Nature Cell Biology by Buchinger Wilhelmi in Überlingen gives some important insights into the role of spermidine during fasting that help to explain the many positive effects of fasting on people’s health.
What is spermidine?
Spermidine is a biogenic polyamine – an endogenous substance that occurs in all human body cells and all living organisms. Certain intestinal bacteria can also produce spermidine. It owes its name to the fact that it was first detected in sperm. The organism needs spermidine to initiate vital cell cleaning processes, known as autophagy.
This fascinating neurotransmitter has endured throughout evolutionary history and across all species, from plants to humans, as a universal mechanism that works with mTOR, a key regulator of cell growth and metabolism, to fine-tune the cell’s response to its environment.
How does spermidine work?
A study published by the universities of Innsbruck and Graz in 2018 showed that a spermidine-rich diet can have a positive effect on life expectancy and cell health. Further studies dealt with the effect of spermidine on cognitive performance in ageing model organisms, on chronic inflammation (e.g. arthritis) and intestinal health. The results were also positive. Spermidine appears to help keep nerve cells flexible and stabilise telomeres, the protective “caps” on the end of chromosomes that shorten and deteriorate with age.
Spermidine owes its ability to rejuvenate cells and promote health primarily to its function as a signal transmitter for the autophagy process, in which misfolded proteins, cell structures that are no longer functional or no longer required are broken down and recycled into new cell structures. Because spermidine production decreases as we age (starting at around 35 years), causing the autophagy process to grow weaker and less efficient, deposits accumulate in the cells over time that can promote diseases such as arteriosclerosis, diabetes, cancer or dementia.
Longevity research therefore focuses on the question of whether and how to counteract this: Can the body’s own spermidine production be (re)stimulated? What are the effects of a spermidine-rich diet? Can it also make sense to take appropriate dietary supplements? Are there any undesirable side effects?
Spermidine and fasting
A study published in the renowned scientific journal Nature Cell Biology in 2024 with input from Françoise Wilhelmi de Toledo and Franziska Gundler from Buchinger Wilhelmi in Überlingen provided important results regarding the role of spermidine during fasting. The study was based on samples from 109 participants of the so-called “Detox study” and a sub-group of the world’s largest study on fasting, a one-year observation study from 2016.
The content of polyamines and their metabolites in the samples were measured and analysed, revealing a consistent increase in polyamine content during fasting. In other words, fasting, intermittent fasting and caloric restriction can significantly increase the concentration of spermidine in the cells. Furthermore, the team discovered that this increase in the body’s own spermidine concentration was a basic prerequisite for the invigorating effects of fasting. When spermidine synthesis was blocked in experiments, the positive health effects of fasting disappeared.
Spermidine therefore plays an important role in ensuring the effectiveness of fasting. As the results of the study show, there is a direct correlation between fasting, spermidine concentration and improved autophagy that is important for a long, healthy life. Among other things, this also leads to the conclusion that long-term fasting at Buchinger Wilhelmi triggers autophagy, and that spermidine can be a marker for this.
Advantages of a spermidine-rich diet
The health benefits of a spermidine-rich diet have been researched extensively for several years. All scientific studies to date conclude that a high level of spermidine in the diet has a positive effect on cell health, the immune system and life expectancy and can delay an age-related decline in cognitive performance.
Spermidine is contained in many foods, but often only in very small quantities. Wheat germ is an excellent source of spermidine; other good plant-based sources with an average spermidine content are mushrooms, green peas, soya beans, cauliflower, broccoli and potatoes. Mature cheese such as cheddar or parmesan is particularly rich in spermidine. Mussels and game also contain significant amounts.
According to specialist literature, a daily intake of 1-5 mg of spermidine is currently recommended. Here are a few examples of foods that can help to cover your daily requirements in a natural way:
- 20 g cheddar (2 mg spermidine)
- 100 g cauliflower (3 mg spermidine)
- 150 g green peas (10 mg spermidine)
- 200 g cooked soya beans (10 mg spermidine)
- 15 g wheat germ, e.g. on salad (4 mg spermidine)
Is it advisable to take spermidine supplements?
In light of the results of studies into the positive effects of spermidine, taking dietary supplements may seem a logical idea. After all, why make the effort to fast regularly or consciously follow a spermidine-rich diet when you can easily achieve the same effect with one or two capsules a day? But it is not quite that simple. No study carried out on humans to date has proved that taking spermidine supplements has any benefits for healthy people. As a placebo-controlled trial by the Lübeck Institute for Nutritional Medicine shows, the spermidine provided in food supplements, even if it is in a higher dose than in most preparations, does not actually get to where it could have an effect, but is evidently metabolised and broken down beforehand.
Does spermidine have any unwanted side effects?
There is no evidence of any negative side effects of natural spermidine in studies carried out so far. The possibility of consuming too much spermidine in food does not appear to be relevant; however, consumer organisations warn against the long-term use of supplements containing high doses of spermidine because their effects have not yet been sufficiently researched. If you want to benefit as much as possible from the positive effects of this polyamine on your health and longevity, you should therefore opt for regular fasting and a spermidine-rich diet.
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