Chronological age — the number on your birthday cake — is lying to you.

At least when it comes to colon cancer risk.

A new study found that your biological age — the wear-and-tear level of your cells — may be a much better predictor of whether you’ll get colorectal cancer (CRC) than how many birthdays you’ve had. And here’s the kicker: that biological clock can be sped up or slowed down by your lifestyle choices.

Wait, Biological Age?

Yup. While your driver’s license says you’re 45, your cells might think you’re 60 — or 35 — depending on how you live.

Scientists can now measure this “cellular age” through things like:

  • DNA methylation (DNAm) — chemical tags that change how your genes behave,
  • PhenoAge — a biomarker-based score that estimates how old your body feels,
  • HD score — a marker of how messed up your internal systems are, basically your body’s chaos meter.

And here’s what researchers discovered: people whose biological age is running ahead of their real age have a much higher risk of colorectal cancer — especially the kind that hits people under 50 (early-onset CRC).

The Scary Rise of Young-Onset Colon Cancer

Colorectal cancer used to be an “old person’s disease.” Not anymore.

Cases in people under 50 have been climbing fast over the past two decades.

Scientists are now thinking it’s not just about bad luck or family history — it’s about accelerated biological aging. In other words, some people’s cells are burning out faster than others’, and that may be why 35-year-olds are suddenly being diagnosed with something that used to hit retirees.

The Study

Researchers looked at thousands of people, tracking lifestyle habits, DNA data, and how “old” their bodies seemed at a molecular level.

Then they ran a series of genetic and epigenetic analyses (a.k.a. a deep dive into your body’s software code) to figure out why biologically older people were more likely to get colon cancer.

Here’s what they found:

  • Biological aging (based on PhenoAge and HD scores) = higher CRC risk, especially early-onset.
  • Unhealthy lifestyle (smoking, bad diet, too much booze, no exercise) = faster biological aging.
  • Faster biological aging = part of the reason bad habits cause cancer in the first place.

So yeah, lighting up that cigarette or skipping workouts isn’t just “bad for you” — it’s literally aging your cells and flipping genetic switches that increase cancer risk.

The DNA Clues

The researchers went even deeper and found specific gene changes that might explain this whole chain reaction:

  • TNF — a gene involved in inflammation (a known cancer trigger).
  • BICC1 — linked to cell growth and possibly tumor blood supply.
  • DIP2B — helps control DNA methylation, the process that can silence or activate cancer-protecting genes.
  • NCF2 — manages oxidative stress, your cells’ version of rust prevention.

When the DNA tags (methyl groups) around these genes go haywire, their expression changes — and that may set off a chain of inflammation, cell damage, and cancer formation.

So, Can You “De-Age” Your Cells?

Kinda.

The good news is that biological aging isn’t totally out of your control. The study found that healthy habits can slow it down, and maybe lower your colon cancer risk in the process.

What helps:

  • A healthy diet (more plants, less processed junk)
  • Regular physical activity
  • Not smoking
  • Limiting alcohol

Researchers estimate that part of the cancer-preventing power of a healthy lifestyle comes from keeping your biological age younger. Basically, living clean slows your molecular clock.

The Big Picture

Here’s what this all means:

  • Your real age doesn’t tell the full story.
  • Some 40-year-olds have the biology of a 55-year-old — and that might be why colon cancer is creeping up on younger people.
  • Your habits can speed up or slow down your biological clock.
  • Future colon cancer screening or prevention could one day involve testing your “epigenetic age.”

Quick Summary

Scientists just connected the dots between biological aging, lifestyle, and colon cancer:

  • Live unhealthy → your cells age faster
  • Cells age faster → DNA changes → inflammation + cancer risk
  • Live healthy → your cells chill out → cancer risk drops

It’s not just about getting older — it’s about how fast your cells think you’re aging.

So the next time you say, “Age is just a number,” your colon might be silently disagreeing.

Sun J, Liu M, Zhang X, Li X, Ye J, Zhao J, Zhou S, Ji H, Tan Y, Bian Z, Zhang D, Dunlop MG, Song M, Smith-Warner SA, Wu H, Theodoratou E, Cao Q, Li X. Accelerated biological aging and its hallmarks in DNA methylation drive the association between unhealthy lifestyles and the onset of colorectal cancer. EBioMedicine. 2025 Nov 5;122:106005. doi: 10.1016/j.ebiom.2025.106005. Epub ahead of print. PMID: 41197401.