Higher dietary iron appears to support healthier epigenetic aging signatures and lower mortality risk, according to a long-term US study.
Dietary iron may do more than support your blood. New research suggests it could help slow aspects of biological aging.
A major study drawing on two decades of US health data has found that older adults who consume more dietary iron show more favorable epigenetic aging profiles and lower mortality risk [1]. The findings point to a surprisingly modifiable factor in the pace at which we biologically age, and underline why getting your iron levels checked should be part of modern preventative health.
The analysis, which included 2,398 adults aged 50 and above, examined how daily iron intake relates to DNA methylation (DNAm), one of the most validated biomarkers used to estimate biological age. These “epigenetic clocks,” including well-known markers such as GrimAge, often predict long-term health outcomes more reliably than traditional risk factors.
Epigenetic aging is the speedometer of your biological wear-and-tear. It reflects how lifestyle, diet, inflammation and environmental exposures leave chemical marks on your DNA, influencing how genes behave without altering the genes themselves.
In this study, higher iron intake was linked with lower levels of several DNAm markers associated with mortality, including GrimAge2Mort, CRPMort and B2MMort. Lower scores on these clocks have consistently been associated with better long-term health.
According to the authors, “higher dietary iron intake was significantly associated with favorable epigenetic profiles,” particularly in markers known to predict all-cause and cardiovascular mortality.
Iron and mortality risk
The study didn’t stop at biomarkers. Over the 20-year follow-up period, 1,321 participants died, allowing researchers to assess how well iron intake predicted real-world outcomes.
Higher iron intake was directly linked with:
- 7% lower all-cause mortality risk (HR = 0.93)
- 13% lower risk of death from heart disease (HR = 0.87)
- 28% lower risk of death from respiratory diseases (HR = 0.72)
Crucially, the research also showed that the aging-related biomarker GrimAge2Mort mediated 22.7% of iron’s protective effect on mortality, suggesting iron doesn’t just correlate with better aging, but may play an active biological role.
Why would iron influence epigenetic aging?
Iron is a double-edged nutrient. On one hand, it’s essential for oxygen transport, energy metabolism, DNA synthesis and enzyme activity. On the other hand, excess free iron can generate oxidative stress, which accelerates aging.
Yet, the researchers highlight mechanisms showing why adequate iron intake, not deficiency or overload, may be key:
- Iron serves as a cofactor for TET enzymes, which regulate DNA demethylation, a core process in epigenetic maintenance.
- Stable iron levels help reduce inflammation-related oxidative damage, which otherwise disrupts methylation patterns.
In short, iron appears to help maintain the molecular “rhythms” of healthy aging, but there is such a thing as too much or too little.
Why this matters for you
Iron deficiency remains one of the most common nutrient gaps worldwide, especially among women, older adults, people with chronic inflammation, and those on plant-based diets. Conversely, iron overload – though rarer – can also be dangerous.
A takeaway from this study is not to start supplementing blindly. Instead, it reinforces the importance of understanding your iron status, eating a balanced diet and integrating regular biomarker testing through evidence-based longevity clinics.
For individuals optimizing their healthspan, this adds iron to the growing list of nutrition and lifestyle levers that can meaningfully influence biological aging trajectories. And as more clinics adopt DNAm-based age testing, insights like this can guide personalized strategies rather than one-size-fits-all nutrition advice.
The bottom line
This long-term population study offers some of the most substantial evidence yet that dietary iron is a modifiable driver of epigenetic aging and survival in older adults. While the science of biological age continues to evolve, the message is clear: nutrients matter, and iron may be one of the most impactful, provided it’s kept in healthy balance.
With the help of our trusted Longevity Clinics Directory, you can make informed decisions that support better aging, stronger metabolic health and improved long-term outcomes.
[1] https://link.springer.com/article/10.1186/s13148-025-01986-x#Sec1
