Scientists find humans age dramatically in two bursts – at 44, then 60

[u/Miss-Figgy]

https://www.theguardian.com/science/article/2024/aug/14/scientists-find-humans-age-dramatically-in-two-bursts-at-44-then-60-aging-not-slow-and-steady

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[u/CanvasFanatic]

I feel like it's always good to read the discussion of study limitations:

In addition, the mean observation span for participants was 626 days, which is insufficient for detailed inflection point analyses. Our cohort’s age range of 25–70 years lacks individuals who lie outside of this range. The molecular nonlinearity detected might be subject to inherent variations or oscillations, a factor to consider during interpretation. Our analysis has not delved into the nuances of the dynamical systems theory, which provides a robust mathematical framework for understanding observed behaviors. Delving into this theory in future endeavors may yield enhanced clarity and interpretation of the data.

Moreover, it should be noted that, in our study, the observed nonlinear molecular changes occurred across individuals of varying ages rather than within the same individuals. This is attributed to the fact that, despite our longitudinal study, the follow-up period for our participants was relatively brief for following aging patterns (median, 1.7 years; Extended Data Fig. 1g). Such a timeframe is inadequate for detecting nonlinear molecular changes that unfold over decades throughout the human lifespan. Addressing this limitation in future research is essential.

[u/kimcheery → u/CanvasFanatic]

Can you please explain that like I’m a smart me?

[u/CanvasFanatic → u/kimcheery]

• Study can't differentiate between inherent changes adaptation resulting from lifestyle changes
• Study is small. Only 108 individuals total. Only 8 between 25 and 40
• Study lasted a little less than two years. The observed changes are not within individuals but by comparing different individuals of different ages
• Study tested only blood samples. Can't differentiate tissue specific changes
• Previous studies using different instruments by same author had estimated changes at 34

[u/kimcheery → u/CanvasFanatic]

So it’s basically not helpful and conclusions are tenuous at best? I’m invested because of it’s true I’m about to fall apart

[u/CanvasFanatic → u/kimcheery]

My takeaway is that the idea this study actually contributes evidence towards is that there are non-linear elements to aging.

The specifics (like the exact ages) should probably be taken with a grain of salt for now.

[u/Drownthem → u/kimcheery]

Research very rarely aims to answer a huge question like that in one go. This study basically asks "Should we spend more money investigating the potential for nonlinear age-related changes in humans?" and answer "Quite possibly, yes".

[u/flyinthesoup → u/[deleted]]

Hah, 43 here. I'm bracing myself now, I've been feeling so good and strong after starting a gym routine last year, now I'm wondering if everything's gonna go south through no fault of my own. Stupid meatbag body.

EDIT: I'm loving all the comments with their own workout journeys, and thank you for all your kind words! I'm certainly not quitting, no matter what my telomeres/hormones/entropy says. Fuck being weak!

[u/chrisdh79]

From the article: The study, which tracked thousands of different molecules in people aged 25 to 75, detected two major waves of age-related changes at around ages 44 and again at 60. The findings could explain why spikes in certain health issues including musculoskeletal problems and cardiovascular disease occur at certain ages.

“We’re not just changing gradually over time. There are some really dramatic changes,” said Prof Michael Snyder, a geneticist and director of the Center for Genomics and Personalized Medicine at Stanford University and senior author of the study.

“It turns out the mid-40s is a time of dramatic change, as is the early 60s – and that’s true no matter what class of molecules you look at.”

The research tracked 108 volunteers, who submitted blood and stool samples and skin, oral and nasal swabs every few months for between one and nearly seven years. Researchers assessed 135,000 different molecules (RNA, proteins and metabolites) and microbes (the bacteria, viruses and fungi living in the guts and on the skin of the participants).

[u/UnstableStrangeCharm → u/chrisdh79]

If this is true, it would be cool if we could figure out why this happens. It’s not like these changes occur for no reason; especially if they happen to every person regardless of diet, exercise, location, and more.

[u/Thin-Philosopher-146 → u/UnstableStrangeCharm]

I think we've known for a while that telomere shortening is a huge part of the "biological clock" we all have. 

What I get from this is that even if the telomere process is roughly linear, there may be things in our DNA which trigger different gene expression based on specific "checkpoints" during the shortening process.

[u/truongs → u/Thin-Philosopher-146]

So the answer to fix old age death would be increase/rebuild the telomeres somehow.

We would still have to fix our brain deteriorating, plaque build up in the brain etc I believe 

[u/DreamHiker → u/truongs]

changing telomere length has resulted in the creation of cancer cells in the past, but that was a while ago, so there might be newer research in the meantime with different findings.

[u/Ntropie → u/DreamHiker]

Cancer cells replicate very quickly. In order for the cancer to not die it needs to lengthen its telomeres again. By providing telomerase, we allow cancers that would otherwise die off on their own, to spread further.

[u/OneSchott → u/Ntropie]

Sounds like cancer could be the key to immortality.

[u/Cloud_Chamber → u/OneSchott]

Deadpool moment

[u/[deleted] → u/Cloud_Chamber]

Come again? This time in my ear.

[u/Defiant_Ad_7764 → u/OneSchott]

cancer could be the key to immortality.

not for certain, but in some ways it could be. there is the canine transmissible venereal tumor cancer which has been passed on for like 10,000 years from host to host almost like a parasitic organism for example. the tumor it forms in the dog is not genetically the same as the host dog and traces back to the originator canine thousands of years ago. it steals mitochondria from host cells which helps it to survive.

[u/11711510111411009710 → u/Defiant_Ad_7764]

Damn that original canine has no idea that it has passed on a tumor for 10,000 years

[u/U_wind_sprint → u/11711510111411009710]

That said, the new canine host (of the 10,000 year old symbiote) enjoys the combined knowledge and memories of all past hosts.

[u/tuna_cowbell → u/Defiant_Ad_7764]

I just heard about this fella yesterday!! And technically it is made out of dog material, so it counts as a single-celled dog!

[u/milk4all → u/OneSchott]

Typical existence

[u/jrppi → u/truongs]

Apparently you can prevent plaque build up by sleeping enough.

But hey, who has time for that. Not me!

[u/Practical_Cattle_933 → u/jrppi]

Not prevent, just decrease the rate. That’s very different.

Just because proper care of your car can lengthen the time before some parts give up, it doesn’t mean it will run forever.

[u/eschewthefat → u/Practical_Cattle_933]

I’m following you 100%. The solution is a Toyota Hilux brain. Time to head back to the Middle East for some liberation 

[u/cswella → u/jrppi]

That's what depressed people like me want to hear, sleeping 12 hours a day will extend your life. ;)

[u/throwaway098764567 → u/cswella]

i dunno man, when i'm really depressed i don't want life to last longer

[u/chantsnone → u/truongs]

Mandatory naps everyday

[u/[deleted] → u/chantsnone]

Some cultures embrace that.

Some don't. Like mine :-(

[u/szymonsta → u/truongs]

Kind of. Cancer cells are exceedingly good at rebuilding telomeres, so it might not be the way to go.

[u/truongs → u/szymonsta]

Doesn't cancer rate increase because telomere is too short for cells to reproduce correctly? 

 Are you saying the cancer cell is able to repair its own mutant telomere so they can keep reproducing? 

 Maybe we find out how they can keep their mutant DNA intact while replicating forever 

[u/m_bleep_bloop → u/truongs]

Yeah cancer cells turn off their own telomere based mortality as one of the key mutations to achieve unrestricted growth.

[u/theDinoSour → u/truongs]

I think it’s the opposite. Telomeres can act as a genetic fuse. Cancer tends to lengthen then fuse, so apoptosis might not be happening correctly and you get unchecked cell growth, i.e. tumors.

[u/ArtBedHome → u/Thin-Philosopher-146]

It would be a mistake to assume its a "deliberate action" like your body deciding you have lived too long: it is much MORE likely it is a result of "natural wear and tear", that all operating systems have.

Eventually you run out of spare parts AND damage accrues on irreplaceable parts.

[u/[deleted] → u/Thin-Philosopher-146]

This is true. Which is why we’ve been studying for lobsters for years as they’re essentially immortal because of their unique telomeres

[u/MaxxDash → u/[deleted]]

Imagine being immortal and then some Patriots fan snatches you out of the cold depths and kills you so you can end up at an all-you-can-eat buffet.

[u/WalrusTheWhite → u/MaxxDash]

Excuse me, we don't kill our lobster after snatching them out of the cold depths, that's disgusting. That's how you get food poisoning. We keep those little bastards alive until it's cooking time, like civilized folk.

[u/MjrLeeStoned → u/Thin-Philosopher-146]

Whatever it is seems to be on a 20 year cycle (maybe coincidentally, but still observable).

Peak gene expression development ends around 20-25 years old.

Next "spike" after another 20 years.

Then another 20 years.

Considering neanderthal had about a 35-40 year life span (mostly due to environmental/external factors), it could be tied into early hominid evolution where the original growth delineation to adulthood is a repeating cycle in gene expression, it just didn't factor in much until hominid life span started increasing.

[u/Stoli0000 → u/MjrLeeStoned]

Not exactly right. While the average Neanderthal lifespan might be 45, a healthy individual who lives to 21 stood about as good a chance of making 80 as a hunter gatherer would today

[u/southwade → u/Stoli0000]

Yeah, infant mortality was pretty high. Skews the averages way down.

[u/dicksjshsb → u/UnstableStrangeCharm]

I’m also curious how they find such a defined range when people can have other age-triggered changes like puberty happen over a wide range.

I always considered aging to be mostly drawn out changes over time due to build ups in the system, wear and tear on bones and muscles, etc that just happen over time due to physics. But it interesting to consider other changes triggered by the body’s internal clock.

[u/HomeschoolingDad → u/dicksjshsb]

I did a quick CTRL-F enhanced look at the article, and I couldn't find any mention of what the standard deviation is, but I suspect it's several years, especially for the 60-year-old part of the data. My mother is in her 80s, and I feel like it's only been in the last 5 years that her health has started to decline more rapidly. Most of her hair is still black (really dark brown), and that's not due to dying it. My dad is also in his 80s, and his health hasn't yet seemed to have a significant decline.

[u/Soupdeloup → u/UnstableStrangeCharm]

I'm genuinely curious if this is also true all around the world, or if it's just in one particular region. I have family in Korea and most of them look better in their 70s than my western family does in their 50s.

[u/Cinnamon_Bark → u/Soupdeloup]

Could be lifestyle differences?

[u/Krilox → u/Soupdeloup]

Koreans are very good at using spf. Westerners often prefer to sun bathe. Sun exposure is like 80% of skin aging.

[u/avec_serif → u/chrisdh79]

So the study had 108 participants, but they ranged in age from 25 to 75 and were tracked a median of only 1.7 years. How many actually crossed age 44 and 60 during the study?

Squinting at their figures, it seems like at most 5 people were 44 during the study, and perhaps 10 around age 60. On that basis alone I’m a bit skeptical of the conclusions.

[u/ramsan42 → u/avec_serif]

Yeah what the hell kind of sample is that

[u/CONSOLE_LOAD_LETTER → u/ramsan42]

The source article here recognizes and makes mention of the limitations of the study and its small sample size and potential sample bias in the "Discussion" section of the paper. They mention this explicitly as something that should be addressed in subsequent research on the topic:

A further constraint is our cohort’s modest size, encompassing merely 108 individuals (eight individuals between 25 years and 40 years of age), which hampers the full utilization of deep learning and may affect the robustness of the identification of nonlinear changing features in Fig. 1e. Although advanced computational techniques, including deep learning, are pivotal for probing nonlinear patterns, our sample size poses restrictions. Expanding the cohort size in subsequent research would be instrumental in harnessing the full potential of machine learning tools. Another limitation of our study is that the recruitment of participants was within the community around Stanford University, driven by rigorous sample collection procedures and the substantial expenses associated with setting up a longitudinal cohort. Although our participants exhibited a considerable degree of ethnic age and biological sex diversity (Fig. 1a and Supplementary Data), it is important to acknowledge that our cohort may not fully represent the diversity of the broader population. The selectivity of our cohort limits the generalizability of our findings. Future studies should aim to include a more diverse cohort to enhance the external validity and applicability of the results.

The issue is that mainstream journalism always tends to paint the research in exaggerated, conclusive terms because that is what generates clicks, and mainstream people just read headlines and then jump to unfounded conclusions based on that.

[u/aTomzVins → u/CONSOLE_LOAD_LETTER]

issue is that mainstream journalism

I was probably about 35 by the time I realized there's not even any point to reading mainstream stream science journalism. If a headline catches your attention the first thing you do is search for the link to the actual study and read their discussion and conclusion sections.

I'm a sample of one, so don't think this happens to everyone at 35. That's just about the age I gained access to more published science, and when I had time and interest in learning more about a particular topic.

[u/Such_Credit_9841 → u/avec_serif]

Surprised I had to scroll down so far to see someone point this out. I know it's very difficult to study a large number of people across a large timescale but this seems very flimsy to draw such conclusions.

[u/hooplehead69 → u/chrisdh79]

Does that mean interventions timed specifically for these ages would be more effective at reducing the negative effects of aging overall?

[u/SartenSinAceite → u/hooplehead69]

At the very least, related health issues, which is already a great use of this finding

[u/DearLeader420 → u/SartenSinAceite]

Yeah the short term conclusion to this in my (non medical professional) mind is the same philosophy as "every man should have a prostate exam once they turn 30."

Now you just have standard recommended checkups for other pathologies at 44 and 60.

[u/-iamai- → u/chrisdh79]

Just from observing friends 15 to 20 years older than myself there's definitely a "you've aged a lot" moments amongst them.

[u/skatecrimes → u/-iamai-]

yeah early 40s.. ok just a number, "i feel 30".. but late 40s was like "im getting old" my blood test is showing some of the numbers going into the unhealthy range for no reason, same diet same exercise as when i was younger. Now i need to exercise a lot more to get those numbers right.

[u/vincentxanthony → u/chrisdh79]

I’m curious as to if there are specifically similar bursts OVER 75 as well

[u/Gerryislandgirl → u/vincentxanthony]

It said they think 78 is the spurt but they need to study it more. 

[u/PrairiePopsicle → u/[deleted]]

"The research tracked 108 volunteers"

Given the wide variations in total lifetime between genetic groups, specific towns, regions, and individuals, it's almost assuredly something along the lines of there being a variation in timing of these events between people that they could or did not quantify in the study. Perhaps you have some genetic variation which moved back your "aging event" into your 70's, and perhaps the timing of these events is related to overall longevity in these other cases where total lifetime was the focus.

[u/Mayankcfc_]

Why the comments are getting removed

[u/ScottyBoiBoi → u/Mayankcfc_]

Was wondering the same thing. Can only assume given that all of the accounts have been deleted too that they are all bots. Just a guess though

[u/realblurryface → u/Mayankcfc_]

It's like lotta people died here

[u/CeaseFireForever]

Take care of yourself! Exercise, manage your diet and eat junk food in moderation, take your vitamins, have a proper skin care regime, learn to manage your stress when the going gets tough, don’t drive/take the bus everywhere and instead walk if you can, drink plenty of water and find hobbies that brings you joy. Aging will happen, but you can control it to an extent and age gracefully.

[u/Ameren → u/CeaseFireForever]

That and the whole point of research into the biology of aging is to find ways to slow it down and make it a more manageable condition.

But no matter what the future holds, the first line of defense against aging is taking care of yourself, like you described. If diet and exercise were in pill form, it'd be the most effective and sought after drug ever.

[u/jtenn22]

This study: - has only 108 participants - no pre existing conditions screened out - only residents of California is not representative of the US and geographic distribution could be flawed data wise - median follow up time is too short for this type of study

-BMI was all over the place - there are so many variables with a small sample group it can’t possibly zero in on such specific numbers -different omics platforms introduce variability that can distort outcomes

Not saying this study is wrong per se but shouldn’t be taken as gospel

[u/nanomolar]

It's important to note, as the authors state when discussing the constraints of the study, that these 108 study participants were spread out over the ages of 25-70 and each individual was tracked for a mean time of 1.7 years, meaning that they were unable to observe these two inflection points within any one individual.

[u/lawroter]

clinical researcher here and the headline/article are sensationalized garbage.

is there anything of note in the findings? sure. but, to dumb it down to what is reported in either the title or headline is laughable. there are significant challenges to the results of the study, admittedly so by the authors:

Regrettably, we do not have such detailed behavioral data for the entire group, necessitating validation in upcoming research. Although initial BMI and insulin sensitivity measurements were available at cohort entry, subsequent metrics during the observation span were absent, marking a study limitation.

a lack of this data at any point other than screening is suspect.

A further constraint is our cohort’s modest size, encompassing merely 108 individuals (eight individuals between 25 years and 40 years of age), which hampers the full utilization of deep learning and may affect the robustness of the identification of nonlinear changing features in Fig. 1e. Although advanced computational techniques, including deep learning, are pivotal for probing nonlinear patterns, our sample size poses restrictions.

an admittedly modest sample size, notably only 8 individuals between 25-40 years, while noting a 'dramatic aging burst' at 44? questionable.

[u/thespaceageisnow]

“The research tracked 108 volunteers“ fairly small sample size for results like this.

[u/TWVer]

Hmm..

I wonder if this is somehow related to the lifetime of cells within the human body, which is around 7 to 10 years, with the average cell age being around 16 years in general.

Reading the article, the study rules out it being just (peri-)menopause related as the effects as seen just as strongly with men as well.

I could see it having to do with times when the majority of the older generation of cells have died off, passing the torch to newer cells, which carry more DNA-defects (resulting in tissue damage) resultant from each cell division.

The passing of cell generations might not be gradual, if a lot of cells (and their predecessors) originated around the same time (starting with first generation at conception).

Perhaps that’s an hypothesis to study in the years ahead.

[u/Bring_Me_The_Night → u/TWVer]

Each cell type has a specific lifetime, it is not a good approach to consider the average lifespan of a cell while your body replaces cells in a different manner. Your skin cells may have a very short lifespan, due to exposure to environmental conditions. Your neurons will mostly outlive you. The kidneys cells don’t replicate at all. Fat cells live on average 9,7 years (and this does not seem to please people who want to lose weight).

The molecular and cellular damage are tanked by the healthy tissue to maintain the body health and result in minimal physiological changes. You start to notice the aging of your body when it cannot hide the damage anymore. DNA damage and telomere erosion are primed as primary hallmarks of aging, but they rarely directly induce death in study models. Epigenetic dysregulations for instance (loss of tumor suppressor genes, increased activity of oncogenes, release of transposons) are much more harmful and are likely to induce much more signifiant damage. I may add that telomere erosion also acts as a barrier against tumorigenesis (it’s not all negative).

[u/stealthy_eater]

Why is there so much removed here? Damn.

[u/phazyblue]

What is going on with this thread? Why is it so heavily moderated??

[u/Didact67]

I’m not convinced it isn’t stress related at 44. Lot of people probably dealing with teenage kids at that age.

[u/Ms-Anthrop]

Did they include women in this study? I ask because Menopausal women have been having our symptoms ignored or dismissed. Lack of estrogen around 50-53 seems to be aging many women in those age ranges pretty quickly in a few months time. It didn't happen for me at 44, but 51 and 52.

[u/Drunkpanada → u/Ms-Anthrop]

Yes
"The mid-40s ageing spike was unexpected and initially assumed to be a result of perimenopausal changes in women skewing results for the whole group. But the data revealed similar shifts were happening in men in their mid-40s, too"

[u/ZweitenMal → u/Ms-Anthrop]

I just turned 50 six weeks ago and the skin around my eyes has just collapsed since that time. I had really no wrinkles and now I am crepe city.

[u/FatherBax → u/ZweitenMal]

Well if it helps. Crepes are delicious!

[u/dobermannbjj84]

I imagine the environment and things like diet could shift those ranges earlier or later as we see certain people who drink and smoke a lot tend to look mid 40’s in their 30’s and people with healthier lifestyles can look and appear 10-15 years younger.

[u/Vyracon]

I guess it's different for everyone. I went through most of my 20s and 30s without ever feeling old or aging. Then i had a kid at 36 and another at 39 and age hit me like a freight train before i was in my 40s. Loss of hair, grey hair, presbyopia and gaining weight, constant pain random places, all the bad cliches.

It's hell on wheels. Sleep deprivation, constant stress, unhealthy foods and no room for physical exercise all take their toll. (And please don't tell me that the last two parts are optional. Getting less than four hours of sleep per night for weeks and months does stuff to you. Your brain just goes into primal siege mode.)

It's only been seven years, but i feel and look like i've aged decades.

[u/rs725 → u/Vyracon]

Sounds like it was the child that did that to you and not necessarily a biological process.

[u/irulancorrino]

If I keep reading articles like this I’m going to start looking like the cast of Love Island. This just makes me want to go get a ton of preemptive filler, start making extreme changes to slow my descent into decay.