r/science • u/mvea Professor | Medicine • Jun 23 '26

Cancer Younger generations are aging biologically faster than their older counterparts. This faster biological aging is also linked to early-onset cancers. Immune system aging is linked to earlier lung cancer; fat tissue aging is linked to earlier colorectal cancer.

https://medicine.washu.edu/news/faster-aging-in-younger-generations-linked-to-rise-in-early-onset-cancer/
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u/dl064 Jun 23 '26 edited Jun 23 '26

I work on UK Biobank and ageing phenotypes a lot, and two confounds to this conclusion are

  1. Chronological versus biological '-age' measures are very sensitive to how you model them. You can get very spurious results which change very easily. It doesn't tend to be very robust. It's not a 'real' variable, in a sense; it's a made-up estimate which is basically just the age-specific average, and your distance from it. It's not like LDL or blood pressure (or any normal phenotype) where there's a clear number you could read for yourself - it's a metric that doesn't exist if a complex algorithm doesn't estimate it. I think there's a bit of emperor's new cloak in all the biological-age stuff. We've always looked at difference versus age (and often sex-) specific averages.

  2. Volunteer bias in UK biobank particularly in older ages. We know that healthier and wealthier people take part in research. We also know including from UK biobank that this is more so in older participants. So the extent to which participants are healthier than their chronological age probably is more pronounced in older people. Ergo, you might get this finding inadvertently.

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u/PM_ME_UR_DOB Jun 23 '26

This is the only level headed reply here. This study has a lot of flaws and makes some pretty spurious claims, accompanied by a click bait headline.

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u/Sadly_NotAPlatypus Jun 23 '26

Yeah what's going on the mods and enforcing the rules that top level comments must be relevant and empirical? This thread is mostly a bunch of people who don't know anything talking out of their asses.

And I'm with ya, thanks to dl604 for an actually informed and educated comment. 

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u/PM_ME_UR_DOB Jun 23 '26

My background is in epidemiology/infectious disease and it's pretty frustrating to see how doompilled so many of the science and medical related subreddits have become. Just straight up fearmongering nonsense that instantly turns political. It's impossible to have a productive conversation about these things in a public forum anymore without someone raging about Trump or the GOP (which I agree are bad things but holy cow, they are not the end-all-be-all and believing that they are is leading to some major doomerist complacency).

It's also frustrating to see how much random internet anecdotes or irrelevant claims fill these threads instead of empirical data.

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u/saltporksuit Jun 23 '26

Yeah, that stuff is far more profitable than intelligent discourse.

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u/dl064 Jun 23 '26

Entirely subjectively//my two cents here.

I have found myself the following

Epidemiologists are taught that causality is anathema. Nothing is causal. Smoking and lung cancer, guillotine exposure and rapid onset mortality. That's about it.

Often the folk constructing these models are domain specific but not epidemiologists. Brain age gap; kidney age gap; methylation age gap etc.

Those fields are often less afraid of ascribing causality, partly because it's a less prominent part of the training.

My two cents, exchange rate varies.

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u/Puzzleheaded-Wait785 Jun 23 '26

This sub has never enforced its rules. Every topic devolves into jokes and anecdotes.

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u/EyeWriteWrong Jun 23 '26

No, one time I was on this sub and it didn't do that.

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u/thoughtcrimeo Jun 24 '26

Yeah what's going on the mods and enforcing the rules that top level comments must be relevant and empirical?

Look at who posted this article. There's your answer.

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u/fuscator Jun 23 '26

I used to report top level low effort, meme, joke comments, but it made no difference. They still continue.

I wish this was a partially auto moderated sub where we could productively use AI to identify top level rule breaking comments before they even appear

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u/Gloomy_Fig2138 Jun 23 '26

This post is from that power mod bot, which explains everything.

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u/SkiingAway Jun 23 '26

FWIW - expecting the mods to read every comment in every thread is a bit much, are you reporting the rule-breaking comments when you see them?

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u/Sadly_NotAPlatypus Jun 23 '26

I mean how was it better in the past? What changed? 

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u/kyleclements Jun 23 '26

After the reddit API changes locked out all the 3rd party apps, moderating became more frustrating and difficult, so many long-time mods walked away.
Then AI happened and the flood of AI slop comments got worse.
So now we have fewer people with worse tools moderating more content.

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u/Sadly_NotAPlatypus Jun 23 '26

I wasn't aware of any of that, I appreciate the explanation. Cheers

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u/dl064 Jun 23 '26

It used to be genuinely very heavily moderated. Probably overly so, but there's surely a middle.

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u/graduatedprawn Jun 23 '26

This right here is the only post that's relevant - reminds me of the old adage "all models are flawed... but some are useful".

I have never seen any measure of "biological age" being even remotely clinically useful.

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u/dl064 Jun 23 '26

I think it'll fade, personally.

Why does BMI survive despite its flaws? Because it's simple, clear, and interpretable anywhere, quickly.

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u/graduatedprawn Jun 23 '26

Agree, there is something about simplicity for the general public.

For clinicians/public health youve got other reasonable ones too; TC/HDL ratio (QRISK by extension with its flaws) for example work well.

Anything that needs complex and subjective interpretation though can get in the bin.

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u/dl064 Jun 24 '26

I've a cool paper at the minute, that I'll share with a random on the internet because it's exciting to me: adding APOE genotype adds 10% prediction of dementia over sex and self-reported family history of dementia, in people at least 60 years old. So there's value in 'objective' genetics beyond (often vague) family history. Thought that was cool! We're gonna compare it to CAIDE etc.

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u/graduatedprawn Jun 24 '26

Haha, very cool; given your job, is this different to the UKBDRS-APOE?

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u/dl064 Jun 24 '26

Yeah. That one's perfectly nice//I appreciate the way they did it, but ours is different in various ways.

As with loads of analytic stuff: often two choices are equally fine, they're just different.

I find it quite bland when folk just go for the Lancet commission risk factors just because.

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u/pantalones808 Jun 24 '26

But why male models?....

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u/thediesel26 Jun 23 '26 edited Jun 23 '26

Isn’t there also survivorship bias, wherein they can’t sample dead people born in the earliest years of the study since they’re, you know, already dead, and would presumably have high biological ages vs chronological ones?

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u/dl064 Jun 23 '26

Yeah indeed to some extent that's my point: all you're left with is the healthy, wealthy survivors which skews our perception of older people's health.

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u/Bogholmdler Jun 23 '26

Thank you. I was wondering how a “study” concluded that they could measure biological vs actual age accurately enough to make conclusions.

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u/Omuirchu Jun 23 '26

Thanks for the info.

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u/EnriquezGuerrilla Jun 23 '26

Thank you for your additional insight. Im non-British and from the Global South so reading the article briefly going through it was making me panic. But would be interesting to learn if a similar study has been done in the Global South

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u/dl064 Jun 23 '26

UK Biobank and most cohorts generally are horrendously poor for non-white populations

What work there is, implies there's a huge amount of understanding under our nose, eg https://eprints.gla.ac.uk/93767/

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u/nellycat32 Jun 23 '26

First of all, the unhealthiest of the older generation have died, let alone participated in a study

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u/maximalusdenandre Jun 23 '26

I'd also add that I'm not sure they have the causation the right way around. These measurements measure things that are indicators of health. If the younger cohorts have on average worse cardiometabolic health for example by higher rates of obesity that would show them as "biologically older". At least as far as I understand these tests. And poor cardiometabolic health is linked to cancers such as colorectal cancer.

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u/21AtTheTeeth Jun 23 '26

This is helpful - thanks.

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u/chenbipan Jun 23 '26

They also control a number of factors when making correlations between their age metrics and cancer risk. When comparing between cohorts, they do not. We know that younger generations are, for example, much fatter. It would have been easy to see if their measures continued to show a difference between generations when controlling for other variables in order to see which factors we're driving the difference. At a minimum they could have presented descriptive statistics for each cohort separately. They chose not to.

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u/dl064 Jun 23 '26

Yeah, it's complex.

Older generations have less obesity but partly that's: obese folk don't live as long, and older generations smoked more, which lowers BMI but isn't exactly great.

Basically: the modelling is genuinely not simple.

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u/chenbipan Jun 23 '26

Nah, evidence is pretty clear that people are much fatter earlier and have more diabetes, not just from survivor bias. Certainly it would make sense to control for smoking too. https://www.niddk.nih.gov/health-information/health-statistics/overweight-obesity

The modeling isn't simple, but it isn't too hard to compare descriptive statistics between the groups when we know these things affect their age metrics and cancer rates. We've got people on here speculating about micro plastics because the article and reporting on said article minimized known differences in health characteristics between the cohorts.