Wheat germ is the single richest everyday food source of spermidine, with concentrations up to 243 mg/kg. But it’s far from the only option. Spermidine is found across a wide range of foods, from aged cheeses and mushrooms to legumes, whole grains, and certain fermented products. The average daily intake in European countries falls between 10 and 15 mg, most of it coming from plant-based foods.
Why Spermidine Matters
Spermidine is a naturally occurring compound in your cells that triggers autophagy, the process your body uses to break down and recycle damaged cellular components. It does this by influencing enzymes that regulate autophagy-related genes, essentially flipping the switch that tells cells to clean house. Your body produces spermidine on its own, but levels decline as you age, which is why dietary intake becomes more relevant over time.
The Richest Food Sources
Plant and fungal foods dominate the top of the list. Wheat germ stands out with concentrations around 243 mg/kg in its raw form, and even after baking into bread rolls, it retains meaningful amounts (roughly 47 mg/kg in finished products made with spermidine-rich wheat germ flour). Dried soybeans come in at about 207 mg/kg, making them one of the most concentrated whole-food sources available.
Mushrooms are another standout. Varieties like shiitake and king trumpet contain roughly 10 to 16 mg per 100 grams. A polyamine database published in Food & Nutrition Research recorded average spermidine levels of about 89 mg/kg in mushroom samples, though this varies by species and preparation.
Legumes as a group are consistently high. Green peas come in around 65 mg/kg when cooked. Lentils, chickpeas, and broad beans all fall in the range of 43 to 109 mg/kg. Seeds like sesame and sunflower also land in that same range, making them easy additions to meals or snacks.
Aged Cheese and Dairy
Aged cheeses rank surprisingly high. Hard-ripened varieties from Spain have been measured at 612 to 670 mg/kg, and blue cheeses aged one to five months averaged around 257 mg/kg. Cheddar and parmesan can reach up to 20 mg per 100 grams. The ripening process plays a major role here: bacterial activity during aging produces polyamines, and the longer a cheese ages, the more spermidine tends to accumulate. Fresh, unripened cheeses contain far less.
Fermented Soy Products
Fermentation can dramatically boost spermidine levels, but the effect depends on the type of fermentation. Natto, the sticky Japanese fermented soybean, contains between 75 and 124 mg/kg of spermidine, making it one of the best fermented sources. Tempeh falls in a similar range. A long-term Japanese study found that regular natto consumption resulted in elevated polyamine levels in the blood, suggesting the body absorbs and uses this dietary spermidine effectively.
Not all fermented soy products follow the same pattern, though. Sufu (fermented tofu) had no detectable spermidine in some analyses, because the specific microorganisms involved in sufu fermentation actually consume spermidine rather than produce it. Miso and soy sauce tend to be higher in other polyamines like putrescine rather than spermidine itself.
Vegetables, Fruits, and Grains
Common vegetables like broccoli, cauliflower, and green peppers all contain notable amounts of spermidine, with green peppers ranking among the higher vegetable sources at over 54 mg/kg in some measurements. Amaranth grain is another option worth noting for people looking beyond wheat germ.
Fruits are more modest. Citrus varieties and pears contain moderate levels, roughly 2 to 3 mg per 100 grams. That’s enough to contribute to your daily intake but not enough to rely on as a primary source.
Rice bran, a byproduct of rice milling, measures around 51 mg/kg and can be mixed into smoothies, oatmeal, or baked goods. Whole grains in general tend to carry more spermidine than their refined counterparts, since the germ and bran layers are where the compound concentrates.
Animal-Based Sources
Meat and organ meats contain spermidine, though at lower levels than most plant foods. Ground beef averages about 72 mg/kg, and chicken liver comes in around 49 mg/kg. Fish sauce is an outlier, with some German-produced samples testing at 1,260 mg/kg, likely due to the prolonged fermentation of fish proteins. That said, fish sauce is used in such small quantities per serving that the per-meal contribution is modest.
Practical Ways to Increase Your Intake
The simplest high-impact change is adding wheat germ to your diet. A tablespoon or two sprinkled on yogurt, cereal, or blended into a smoothie delivers a concentrated dose without changing your routine. Swapping refined grains for whole grains helps as well, since the outer layers of the grain kernel are where spermidine is stored.
Building meals around legumes, mushrooms, and aged cheese covers a lot of ground. A lunch with lentil soup and a side of parmesan, or a stir-fry with tempeh and shiitake mushrooms, can deliver meaningful amounts. For people who eat Japanese cuisine, regular natto consumption is one of the most well-studied dietary approaches to raising blood polyamine levels.
Spermidine is found in both raw and cooked foods, and it appears across a wide enough range of food groups that most people can increase their intake through ordinary dietary choices rather than supplements. Focusing on whole grains, legumes, mushrooms, fermented soy, and aged cheese gives you the broadest coverage from the richest sources.