Spermidine versus Cancer

by Nils Osmar. March 25, 2022

Like many compounds associated with slowing or reversing the aging process, polyamines – including putrescine, spermidine and spermine – have a curious relationship with cancer.

On the one hand, polyamines appears to prevent cancer in humans. Here’s a quote from one recent study:

A recent prospective, observational epidemiological study revealed that individuals that have been eating a diet that is spermidine-rich are characterized by a reduced overall mortality, as well as a decreased mortality by each of the major causes of death, namely (i) cardiovascular, (ii) cancer and (iii) ‘other’ causes,
The association between high spermidine uptake and reduced mortality is independent from confounding factors including age, sex, body mass index, consumption of alcohol or aspirin, metabolic syndrome, diabetes, physical activity, and socioeconomic status, as well as conventional dietary scores distinguishing healthy from unhealthy eating.
These results confirm our long-lasting suspicion that spermidine has broad health-improving effects based on our observation that nutritional supplementation of this polyamine can extend the longevity of multiple model species, including yeast, nematodes, flies and mice

But for those who already have cancer, this study suggests that having high levels of polyamines in the body may accelerate its growth.

To be clear, there’s no evidence that I’m aware of that polyamines “cause” cancer. What concerns some researchers is the possibility that if we already have breast, colon, lung, prostate or skin cancer, increasing our intake of polyamines could make these cancers grow faster.

This is similar in a way to the question of raising NAD levels. The body needs NAD, and our levels are highest when we’re young. NAD helps with DNA repair, which can help prevent cancer from getting started. And young people have far lower rates of cancer than adults. But cancers (like healthy human cells) thrive in a high NAD or high polyamine environment.

By some accounts, millions of people are now taking NAD boosters, and have been now for years. And millions of people eat mushrooms and fermented soy. I have not read any reports of the odds of cancer increasing in this large group as a result.

So What to Do?

I can’t prescribe what other people “should” do, but I can share what I’m doing and why.
I am eating foods high in spermine, spermine and putrescine. (Examples being grapefruit, green peas, fermented soybeans, cooked and cooled potatoes, lentils, broccoli, brie cheese, aged cheddar cheese.)
I recently started (also) taking a spermidine supplement. I had avoided supplements for a long time because they contained less than 0.5 mg per capsule; some companies now have capsules that have several times that amount.
I’m also taking NAD boosters (NMN and niacin), and doing other things which increase NAD levels including saunas, cold exposure, and exercising.
If I had cancer, particularly any of the ones that thrive in a high spermidine or high NAD environment, I’d talk with my doctor and get his advice about removing these nutrients from my diet.