by Malini Gupta
Most of us know iron as a metal. Some may even know it gives blood its red color. But inside our bodies, in our cells, iron plays a stranger and a more consequential role. Iron can determine whether a cell lives, regenerates, or tips toward cancer. So, one may think of iron as a metal which rusts, or just sits quietly in breakfast cereals and multivitamins, seeming ordinary but iron is likely one of the most important substances fueling our lives.
Human body is built like a set of Russian dolls; like a hierarchy in which organs are made of tissues and tissues are made of cells. At the base of that hierarchy are stem cells acting as the body’s repair crew. These cells can copy themselves and transform into whatever the body needs most: a blood cell, a liver cell, a brain cell and so on. But as one gets older, that repair crew slowly shrinks. Damage builds up, the body becomes slower at fixing itself, and iron is quietly involved in all of it.
The irony of fate: Our body must strike a perfect balance, or the metal of life can become the fuse for its collapse
One can think of iron like fire in a home. Fire is essential, it cooks food, provides warmth, makes life possible. But uncontrolled fire is also dangerous. Too little, and the house grows cold. Too much, or in the wrong place, and the same fire can burn the house down. Iron works the same way inside our body: our cells need it to function, but too much or too little can cause serious consequences.
Scientists have discovered that as we age, some of our cells start behaving as though they are running low on iron despite it being present. This state is called functional iron deficiency.1 It is less like a shortage and more like a supply chain problem where the iron exists, but it is not getting to where it needs to go. Cells with less usable iron lose some of their stem-like flexibility, which helps tissues regenerate. Although at first, this may sound entirely bad, here is where the irony begins! A cell that cannot easily reinvent itself may also be less able to take the first dangerous steps toward becoming cancerous.
There is another layer to this. Iron helps run the enzymes that control which genes are switched on or off. When those enzymes are starved of iron, protective genes can go quiet permanently.2 As an example, if these silenced genes played a role in protection against cancer, they lose their function, thus making cells more vulnerable.
Iron can also cause a cell to self-destruct. When iron builds up in the wrong way inside a cell, it can set off a chain reaction tearing apart the cell’s outer layer until the cell collapses. Although dramatic, it is a safety mechanism called ferroptosis. Individuals who absorb too much iron from a condition called iron overload are often at higher risk for liver damage, heart damage and certain cancers. This is because the excess iron overwhelms the body’s ability to keep things in check. So iron, in this sense, is both fuel and fuse; it can power life, and it can light the path to destruction.3,4
When one looks at cancer in general, most of these cells are unusually greedy for iron. To meet the immense pace of proliferation, the cancer cells require large amounts of iron to fuel themselves. But the more iron a cancer cell depends on, the more vulnerable it may be to that same self-destruction mechanism. Scientists are now exploring whether this could be used against cancer, essentially starving tumors of iron or flooding them with enough to trigger their own collapse.
Now to put everything into context, cells have spent millions of years learning to manage iron. Not to eliminate it, not to hoard it, but to keep it precisely where it is needed. Understanding how that regulation breaks down in aging and various diseases like cancers, hematologic disorders or even neurodegeneration is now one of the more active frontiers in cell biology. The answer may one day change how we treat these diseases, slow cellular aging, or restore the body’s repair systems.
For now, what iron tells us is that the most ordinary things, kept in the right balance, are often what life depends on most.
References
(1) Kao, Y.-R.; Chen, J.; Kumari, R.; Ng, A.; Zintiridou, A.; Tatiparthy, M.; Ma, Y.; Aivalioti, M. M.; Moulik, D.; Sundaravel, S.; et al. An iron rheostat controls hematopoietic stem cell fate. Cell Stem Cell 2024, 31 (3), 378–397.e12. DOI: 10.1016/j.stem.2024.01.011
(2) Tisman, G. Part II: The Sound of Silence, Latent Iron Deficiency: Orchestrating Epigenetic Tunes of Neoplastic Transformation. Med. Res. Arch. 2025, 13 (12). DOI: 10.18103/mra.v13i12.7129
(3) Ciscar, M.; Rodríguez-Santana, C.; Santana-Codina, N. Iron and metabolic rewiring in cancer. Oncogenesis 2026, 15(1), 1. DOI: 10.1038/s41389-025-00595-w
(4) Cosialls, E.; El Hage, R.; Dos Santos, L.; Gong, C.; Mehrpour, M.; Hamaï, A. Ferroptosis: Cancer Stem Cells Rely on Iron until “to Die for” It. Cells 2021, 10 (11). DOI: 10.3390/cells10112981
Author
Hailing from Calcutta, India, Malini Gupta is currently a Staff Scientist in New York who finds her greatest joy in the intersection of research and artistic expression. While her professional work is grounded in translational oncology, she is a relentless advocate for science outreach, seizing every opportunity to demystify complex data for the community. When she isn’t in the lab or mentoring, she is likely behind a camera lens, capturing the world through a creative eye that informs both her science and her storytelling.
Illustrator
Anwesha Pal completed her master’s in Inter-disciplinary Biosciences from JNCASR, Bengaluru. She has been trained in molecular biology, gene regulation, and cytogenetics during her academic journey.
She is passionate about studying ageing and age-related disorders with a goal to work in the area to improve the quality of life for many. She enjoys expressing her ideas through sketches and illustrations and is actively interested in science communication.
Cover image by Anwesha Pal
Inset image by Malini Gupta created using Canva and Claude
This article was written as part of Club SciWri’s Science Writing Workshop, an initiative aimed at nurturing new voices in science communication and helping participants explore how to make complex ideas accessible to wider audiences.
Workshop conducted by Saurja Dasgupta, Ananya Sen, Rohini Subrahmanyam, Sumbul Jawed Khan and Roopsha Sengupta
