What is Spermidine?

Let's address the odd name first of all.

The reason for Spermidine's name is that it was first discovered in a sample of semen by the Dutch scientist Antonie van Leeuwenhoek in 1678. He noticed a bunch of crystals while looking down at the microscope.

At this time, he had no idea what he was actually looking at, and spermidine's function was not fully understood until hundreds of years later.

Although spermidine was initially discovered in semen, it is important to note that it is present in all living cells and can be obtained from various food sources.

So what actually is Spermidine?

Spermidine belongs to a group of organic compounds called polyamines. There are 3 main polyamines to be aware of:

1- Spermidine
2- Spermine
3- putrescine

Polyamines are involved in several cellular processes, including cell growth, cell division, and apoptosis (programmed cell death). They are also essential for stabilizing DNA and protecting it from outside stress.

Polyamine levels decline continuously with age and this has been associated with aging and disease. On the other hand, boosting polyamine levels by giving animals Spermidine extended lifespan. (1)

Where do you get Spermidine from?

There are generally 3 ways our cells obtain Spermidine:

1)  Diet

Spermidine is present in many of the foods we eat. But it's particularly high in certain vegetables and fermented products:

1. Wheat germ: Wheat germ is one of the richest dietary sources of spermidine. It is the embryo of the wheat kernel and is often available as a standalone product or as an ingredient in baked goods, cereals, and smoothies.
2. Soybeans: Soybeans and soy-based products, such as tofu and soy milk, contain significant amounts of spermidine. These versatile legumes can be incorporated into various dishes and are commonly used in vegetarian and vegan diets.
3. Mushrooms: Certain types of mushrooms, such as shiitake, portobello, and oyster mushrooms, contain notable amounts of spermidine. They can be enjoyed in soups, stir-fries, salads, or grilled as a side dish.
4. Peas: Peas, including green peas and yellow split peas, are good sources of spermidine. They can be used in salads, stews, curries, or enjoyed as a side dish.
5. Corn: Corn kernels and products made from corn, such as polenta or cornmeal, contain spermidine. Corn can be grilled, boiled, roasted, or added to various recipes as a versatile ingredient.
6. Broccoli: Broccoli is a cruciferous vegetable that contains spermidine along with other beneficial compounds. It can be steamed, sautéed, roasted, or added to salads and stir-fries.
7. Spinach: Spinach and other leafy greens, like kale and Swiss chard, contain spermidine. These greens can be consumed raw in salads or cooked in various dishes like soups, stews, and sautés.
8. Natto: Natto is a traditional Japanese food made from fermented soybeans. It is particularly rich in spermidine and is often enjoyed as a breakfast food or added to rice dishes.

2)  Gut Bacteria

Gut bacteria can also produce spermidine. Some studies have suggested that certain strains of gut bacteria, such as Lactobacillus reuteri, can synthesize spermidine and release it into the intestinal environment. These bacteria can produce spermidine by converting other dietary compounds, such as agmatine, into spermidine. However, the overall contribution of gut bacteria to spermidine levels in the body is still an area of ongoing research.

3) Your cells can make Spermidine

Finally, your cells can also make Spermidine themselves using the amino acid ornithine. This process is called In the body, polyamine biosynthesis. It involves the conversion of the amino acid ornithine into putrescine, which is then converted into spermidine through the action of the enzyme spermidine synthase. (2)

What is Spermidine good for?

In recent years, spermidine has garnered significant attention for its potential health benefits. This naturally occurring polyamine compound has been the subject of extensive research, uncovering its potential importance in various aspects of human health.

With that said, research is still in its early stages and the potential benefits below have not yet been proven in humans.

Cellular Rejuvenation and Anti-Aging

One of the most intriguing aspects of spermidine is its ability to induce autophagy, a cellular process vital for maintaining cellular health and function. Autophagy enables the removal of damaged or dysfunctional components within cells, thereby promoting cellular rejuvenation. By stimulating this process, spermidine may contribute to anti-aging effects, preserving cellular integrity and mitigating the decline associated with aging. (3)

Cardiovascular Health

Spermidine has demonstrated promising cardioprotective effects in animal studies. Some studies have shown that spermidine intake is associated with improved heart function, reduced incidence of cardiovascular diseases, and lower blood pressure. Furthermore, spermidine exhibits anti-inflammatory properties, potentially alleviating inflammation-related cardiovascular conditions. (4)

Neuroprotection

The neuroprotective effects of spermidine have attracted considerable attention. Research on mice suggests that spermidine may help safeguard against age-related cognitive decline and neurodegenerative diseases, such as Alzheimer's and Parkinson's. Its ability to promote autophagy in brain cells may facilitate the removal of toxic proteins, thus reducing their accumulation and protecting against neuronal damage. With that said, a human trial into Spermidine and cognitive decline showed it had no benefit over placebo. The researchers did say that the dose they used (750mg wheat germ extract) may not have been high enough. (5)(6)

Immune System Modulation

Spermidine has shown the ability to modulate immune responses, potentially contributing to a well-balanced immune system. It has been associated with enhanced immune function and the promotion of immune cell production. Additionally, spermidine exhibits anti-inflammatory properties, which may help mitigate excessive immune responses and reduce inflammation-related disorders.  (7)

In summary, Spermidine is showing some promising potential benefits in animal studies. But it's important to emphasize again that human trials are very few in number and have not yielded any significant benefits.

Are there any side effects with Spermidine?

Since spermidine is a naturally occurring compound in the body and found in various foods, it is generally considered safe when consumed in moderate amounts through the diet or via supplements.

However, at the time of writing, there are a limited number of human trials into Spermidine supplementation. A recent study published in 2022 gave 750mg of wheat germ to older adults over a 12 month period and reported no adverse events that were linked to taking the supplements. Of note, this study involved 100 participants which is a relatively small number of people. (6)

It's always advisable to exercise caution when considering any new supplement and consult with a healthcare professional before starting spermidine supplementation.

The other thing to be aware of is that most Spermidine supplements on the market use wheat germ as the source. This means that wheat germ-based Spermidine supplements will contain gluten and should be avoided if you have a history of celiac disease. 

Spermidine fundamentals - Conclusion

That brings us to the end of our look into Spermidine and some of preliminary research into it.

In summary, Spermidine is one of three main polyamines which play an important role in cell health and longevity.

Studies are ongoing, but there is a lot of interest in Spermidine as a potential autophagy inducer. In simple terms, this is the cell's "housekeeping" system that breaks down and discards old misfolded proteins.

The efficiency of autophagy declines with age and boosting levels with a Spermidine-rich supplement is being investigated. With that said, at the time of writing, human trials are limited and the potential upsides of Spermidine are as yet unproven.