New research reveals that certain anti-aging molecules found in spermidine supplements could inadvertently fuel cancer growth. Credit: Wikimedia Commons.
Scientists have identified a precise mechanism that turns some anti‑aging molecules into potential cancer growth. A team from Tokyo University of Science showed that polyamines, natural compounds promoted in supplements such as spermidine, can speed tumor growth by increasing production of a protein called eIF5A2 in cancer cells, through a pathway distinct from their beneficial effects on healthy aging. That dual role places polyamines at the center of a growing safety debate.
Polyamines are small positively charged molecules that every cell needs. They stabilize DNA, help control which genes are active, and support the cell’s protein factories, the ribosomes.
In aging research, higher polyamine levels have been linked to better autophagy, the internal recycling system that removes damaged components and keeps cells functional for longer. This connection explains why spermidine and related compounds have become popular in the longevity world.
Oncologists, however, have long noticed another side. Studies over several decades have reported that tumors in organs such as the breast, colon, lung, and brain often have unusually high amounts of certain natural chemicals called polyamines.
This happens because the body makes too much of an enzyme called ornithine decarboxylase (ODC), which drives the buildup of these chemicals. High ODC expression correlates with more aggressive disease and worse survival in cancers like colorectal carcinoma and neuroblastoma, and blocking this enzyme slows tumor growth in animal models.
The paradox has been why the same class of molecules appears protective in some contexts yet dangerous in others.
Study reveals polyamines cancer growth pathways
The new work helps resolve that puzzle by separating two related proteins. In normal tissues, polyamines act mainly through eIF5A1, a translation factor that supports mitochondria and autophagy and is associated with beneficial aging effects.
In cancer, by contrast, the Tokyo group found that polyamines preferentially raise levels of eIF5A2, an isoform that controls a different set of target proteins and is much more tightly tied to cell proliferation and metabolic rewiring.
Using proteomic analysis (study of the entire set of proteins within a cell or tissue, at a specific time), the researchers showed that silencing eIF5A2, rather than eIF5A1, strongly reduced cancer cell growth and altered the expression of ribosomal proteins such as RPS27A, RPL36A, and RPL22L1, which have all been linked to malignancy.
In practical terms, tumors seem to hijack polyamine signaling so that the “dual role” tilts decisively toward uncontrolled division instead of healthy maintenance.
A small regulatory RNA (a nucleic acid present in all living cells) acts as the switch. Under normal conditions, a microRNA called miR‑6514‑5p binds to the 5′ untranslated region of eIF5A2 mRNA and keeps its translation low.
The team found that polyamines interfere with this microRNA’s function, releasing the brake and allowing eIF5A2 protein levels to rise in cancer cells. Once that happens, the protein can engage the ribosome and help build the specific machinery that tumors need to progress.
Can Anti-Aging Supplements Promote Cancer Growth? Scientists Uncover a Key Mechanism https://t.co/m20QXInNMP pic.twitter.com/oaYHxKTxjY
— HealthIT Policy (@HITpol) February 25, 2026
Supplements face new scrutiny
This biochemical detail has direct consequences for the booming anti‑aging supplement market.
Products that raise polyamine levels, especially spermidine‑based capsules and drinks, are sold on the promise of better cellular cleanup and longer healthspan, yet the new data indicate they could also strengthen the same pathways that tumors use to grow, particularly in people with undiagnosed cancers or high genetic risk.
Regulators and clinicians now face questions about how to advise consumers while evidence in humans is still emerging.
Cancer biologists see opportunity as well as risk. Reviews on polyamine metabolism stress that enzymes like ODC, and now downstream players such as eIF5A2, form a metabolic network that can be targeted with drugs, possibly in combination with existing therapies.
In theory, medicines that selectively block eIF5A2 or its interaction with ribosomes could slow tumor growth while leaving eIF5A1‑mediated healthy aging effects intact, although this remains to be shown in clinical trials.
The dual role of polyamines shows how easily attempts to slow aging can collide with the biology of cancer. By clarifying how the same molecules support longevity in normal cells yet drive malignancy through eIF5A2 in tumors, the Tokyo University of Science team has provided both a warning for supplement use and a road map for new targeted treatments.
This will be a test of whether the anti‑aging field is ready to align its promises with the complex trade‑offs written into cell biology.
