You have probably heard that certain foods are said to help you live longer. Most of that advice sounds familiar by now.
Every so often, though, researchers land on a compound that few of us have ever named.
The compound is spermidine, a natural polyamine that turns up in wheat germ, aged cheese, mushrooms, soybeans and peas.
In a 20-year study of 829 adults from Bruneck, Italy, higher spermidine intake showed the strongest link with lower mortality among 146 nutrients examined.
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The findings from The American Journal of Clinical Nutrition in 2018 pointed to a striking effect size.
People in the top third of intake had a mortality risk that matched being roughly 5.7 years younger than those in the bottom third.
The Bruneck cohort followed adults aged 45 to 84 between 1995 and 2015.
After adjusting for age, sex and calorie intake, the risk of dying during follow-up dropped by about a quarter for each standard-deviation rise in spermidine intake.
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Adjusting further for lifestyle and other dietary factors barely changed the result. Researchers later saw the same pattern in a second Austrian cohort called SAPHIR.
How spermidine may keep aging cells cleaner
Scientists think the effect traces to autophagy, the body's routine cellular cleanup. In simple terms, cells break down damaged proteins and worn-out parts, then recycle them into fresh building blocks.
That housekeeping loses steam over the years. Spermidine appears to switch autophagy back on, according to a 2018 review by Madeo and colleagues in Aging.
The same team notes that spermidine can delay neurodegeneration in mouse models and postpone the appearance of cancer after cancer-causing exposures. Most of that mechanism work sits in animals, so the human picture is still forming.
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The largest randomized trial in people, published in JAMA Network Open, gave 100 older adults with early memory complaints a wheat-germ spermidine supplement for a year.
Memory scores did not improve compared with placebo, though the supplement was well tolerated.
So the food-based signal for longevity is currently stronger than the pill-based one. That gap is one reason nutrition researchers are steering people toward whole foods first.
Where spermidine turns up on the plate
The compound is concentrated in a short list of everyday foods. Levels vary by ripeness, fermentation and preparation, but the ranking is fairly consistent across food databases summarized by News-Medical.
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Food | Spermidine per 100 g |
|---|---|
Wheat germ | up to 35 mg Also read: Your gut bacteria may be an early warning sign of type 2 diabetes |
Natto (fermented soybeans) | about 20 mg |
Aged cheddar | up to 20 mg |
Soybeans | about 18 mg |
Shiitake and king trumpet mushrooms | up to 16 mg |
Cow liver | up to 16 mg |
Legumes | about 10 mg |
Nuts and seeds | 5 to 6 mg |
Citrus fruits and pears | 2 to 3 mg |
A tablespoon of wheat germ on yogurt or oatmeal, a slice of aged cheddar, a handful of sautéed mushrooms or a bowl of edamame all add measurable amounts.
Fermented foods sit near the top because bacterial cultures raise the polyamine content.
Talk to your doctor before starting a spermidine supplement if you take prescription drugs or have a chronic health condition, since long-term safety at concentrated doses is still being studied.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.