> What UK Biobank is revealing, scan by scan and layer by layer, is that disease doesn’t arrive out of nowhere. It accumulates quietly, shaped by genes, environment, and habits.
I think that is already known for a while. It's called functional reserve, and was a big topic in HIV patients (and then again for SARS-CoV-2).
Like people with higher cognitive capabilities will be protected by those a bit longer before onset of HIV-associated neurocognitive disorder (or even dementia).
Same for kidneys: They have a functional reserve that you are born with gets used up during life, until it is gone. Acute kidney disease treatment is aimed at preserving whatever little function is left.
I am a 61 year old guy. I've never been overweight, never smoked, I've never been drunk and drink only infrequently, and have been fitter than average ... sometimes very fit. A few years ago I decided to make an undirected kidney donation. I thought I'd be a slam dunk. Everything was great, except my eGFR (estimate granular filtration rate) was 73, and for many people it is more like 110, which disqualified me, as after donating my number would get cut in half, putting me at some risk.
So I pulled up blood work results going back 15 years that I had records for and found that 73 was my high score! It typically was mid 60s, with a low of 61. I have no idea why it is so low. Anyway, this is the reason I'm relating this story. It seems odd that my kidney function has gone up. It wasn't just a fluke -- I've had bloodwork done at least five times since then and I'm always in the mid 70s now.
eGFR is an indirect measurement of kidney function. It can be slightly lower in some people with normal kidney function for various reasons.
There are additional kidney function tests that would be used for a more complete picture of kidney function if it was suspected that you had a kidney condition. There are more direct GFR tests, minus the ‘e’ prefix which means estimated. However, a better blood test that is more accessible would be Cystatin C. Worth getting one of those as a baseline at some point.
In the content of donation, though, it’s not worth risking it. It’s best to play it safe. If you happened to have been inspired by the kidney donation story and blog that circulated in rationalist communities, it’s also worth noting that it was not a great source of information about the relative risks of the procedure, despite being presented as comprehensive and well researched.
I suspect that my kidney function was negatively affected by a reaction to the contrast used in some medical imaging I had a few years ago. Unfortunately, lack of access to healthcare means I've never been able confirm it. I just know that, before that episode, I was noted for my ability to hold my alcohol; after, no more, and I've had to be careful about taking certain kinds of OTC medication because I can feel it affecting me similarly.
Wouldn't be surprised if there was some source of hidden damage like that.
Maybe you lost weight or changed some aspects of your diet after 50?
I previously looked at eGFR numbers and they seem very ballpark-ish and prone to fluctuation, as their name implies. My understanding is that they are used to detect acute cases, rather than to give a real measurement of your kidneys if you’re well.
Your diet is less salty maybe?
Glomerular not granular
It would be interesting what this functional reserve is, right? The microbiome perhaps, or intracellular minerals? Some other thing we haven’t even identified?
> It would be interesting what this functional reserve is, right?
It is most likely not a single thing.
Looking for "the functional reserve" is like looking for which part of an airplane is the "multiple redundancy". Or which line of code is the "fault tolerance" in google's code base. It is not a single part, it is all the parts working together.
Just looking at the kidney example (which is not the only kind of function we can describe having functional reserve.) functional reserve is that there are two kidneys, and each kidney have multiple renal pyramids, and if this or that part of the kidney functions worse other parts compensate and will work overtime.
Depletion of functional reserve is not something literally running out (like a fuel tank running empty), it is more like a marauding gang shooting computers in a cloud data center. Sure initially all works as it used to, because the system identifies the damaged components and routes the processing to other ones. But if they keep it up they will damage enough that the data center will keel over and can't do what it could do before.
(No, I'm not saying that a human body is literally a data center, or literally an airplane. What I'm saying is that all three shares the common theme that some process is maintained in the presence of faults.)
In case of kidneys, my understanding is that only a certain subset of glomerular cells are actively filtrating blood at any given point. The other cells form the functional reserve, and start to become active once the other cells age out, or are disrupted due to an event (like poisoning, such as mycotoxin damage from eating moldy food). Once the functional reserve is exhausted however, no new cells can become active and you are left with whatever dwindling GFR you have, until you get a transplant.
With the vascular system you have example arterial elasticity which is an important measure of vascular health. When your blood vessels become less elastic it does not immediately cause symptoms, but it increases the risk of heart disease and stroke. This is also why periodontitis and gum disease is a predictor for vascular diseases: Bacteria enter the bloodstream through inflamed oral mucosa and form plaques along the blood vessels.
>"This is also why periodontitis and gum disease is a predictor for vascular diseases: Bacteria enter the bloodstream through inflamed oral mucosa and form plaques along the blood vessels."
And yet in the year 2025 dental care is globally treated as seperate from other healthcare, a strange historical artifact that clings on.
Story from the US: had an awful tooth infection (from a known dead tooth) that I tried to ride out, half my face was swollen up, even my eye looked half shut. Well after a day of this I couldn't take the pain. Called my doctor "we don't pull teeth, you have to call a dentist." So I called a dozen dentist and was told either "we aren't taking new patients" or "we can't get you in for 6 months".
I ended up just driving to a dentist and saying "look at my fucking face! Pull this fucking tooth out!" Finally a dentist was able to spare 30 seconds to yank it. Bill was something like $750.
The US is a dystopian hellhole.
I got a doctor to pull an internal tooth that had formed a cyst around it, a maxillofacial surgeon.
The dentist quoted $1300 but said insurance wouldn’t cover it, it’d be out of pocket. The surgeon did it (I was awake with local anesthesia) for $300 but insurance paid an additional $4000.
Before all this, A PE owned dentist office (the one that didn’t have the six month wait) had told me two years before that the pain I was experiencing was because I had periodontal disease and that I just needed to get a periodontal cleaning (which cost $750 and didn’t help at all, also conveniently not done by a dentist but a dental hygienist). This turned out to be very dangerous because the cyst was pushing and wearing away at my nose bone, and if I’d waited any longer my nose may have sunk into my face.
It’s definitely maddening the hoops one has to go through to get proper dental care in the US.
Regardless of the financial and administrative issues, dentistry is still far more an art than a science. Go to 10 different dentists for any serious condition and you'll likely receive 10 different treatment plans. In most cases they're making good faith recommendations but there's a huge amount of subjectivity and personal bias involved.
Physicians have recently started embracing evidence-based medicine with documented best practice treatment guidelines so hopefully a similar cultural change will come to dentistry in time.
And you couldn’t just board a plane to Mexico or anywhere down south and get the job done for half the price including said flight? People keep complaining but don’t realize that no place is perfect in this world.
What an asinine response.
Functional reserve means you are completely well but the start of the disease is coming closer as the former is depleting.
Another case is when disease starts subtly and slowly _with_ initial symptoms that are otherwise not debilitating. Eg Alzheimer's starting decades ago by being forgetful.
I have no idea which one the post is reffering to.
Thankfully biology has redundancy, so a single cosmic bit flip does not send humans into a BSOD.
In biomed sciences we rarely refer to the huge amount of resiliency of living organisms. They are so robust, stable and self healing that it would need a fleet of human made machines to cover the basic difficulties.
A very elderly doctor referred to "cognitive reserve", lamenting hen had more of it when younger.
Dr Sean Mullen on Twitter "there are now over 500,000 studies on the consequences of SARS-CoV-2 infection" - https://x.com/drseanmullen/status/1924960793264525772 *IF* that's true - yeesh!
Number of studies are meaningless by itself, and an intellectually rigorous scientist wouldn't use that as a metric. We've known for decades that any serious infection can have long lasting effects for some patients. There's nothing special about SARS-CoV-2.
Preventative treatment for disease is ten, hundred, thousand times cheaper than treatment ex post facto.
This holds true for many things. It’s easier to stay in shape and maintain a healthy weight than it is to recover from getting out of shape or overweight. The longer someone spends out of shape or overweight, the harder it becomes to escape the cycle. There’s no better time to start than now.
As for preventative medical treatment: This one is a difficult topic. There’s a popular misconception that getting a lot of different blood tests and imaging scans is a good idea to identify conditions early, but most people don’t understand that these tests (including imagine) are prone to a lot of false positives. Excessive testing has been shown time and time again to lead to unnecessary interventions, leading to worse outcomes on average. A number of previously routine medical tests are now not recommended until later age or until other symptoms appear because routine testing was producing too many unnecessary interventions, producing a net negative benefit.
It’s a hard concept to wrap our heads around when we’re so attached to the idea that more testing means better information. It’s a huge problem in the alternative medicine community where podcast grifters will encourage people to get various tests like organic acid tests or various “levels” testing, then prescribe complex treatment programs with dozens of supplements. The people chasing these tests then throw themselves far out of balance with excess supplements while sinking thousands of dollars into repeat testing
This sounds like an example of a fault in how to take action based on results vice a fault in getting too much data. Perhaps the conclusion you state about the better approach being to forego tests is true. For example, if emotional and legal factors prevent patients and providers from acting rationally here. Optimistically, we can do better.
Any opinion on Outlive: The Science and Art of Longevity by Peter Attia? He seems fairly fact-based, but does recommend several diagnostics.
Only if you have an excellent health insurance plan. Otherwise, preventive treatment costs you money, while curative treatment is paid for you.
Sounds like a misguided incentive ...
My insurance covers annual bloodwork/physicals as well as immunizations. I am pretty sure most health insurance policies do.
An important nit I need to pick…
These are items you receive along with your insurance.
They are not insurable events and they are not “covered” like an insurable event.
Predictable, regularly occurring events cannot be covered by insurance by definition. You can’t adjust it, you can’t assemble a risk pool, etc.
We use the word “insurance” to mean “nice things that I like” but I think we’d have more enthusiasm for socialized medicine if we knew how much of “insurance” was nothing of the sort.
The ACA made this standard. It’s been like this for a long time.
When we were hiring a lot of people out of college, I spent way more time than I expected teaching them about how healthcare works and how to find their own information. We found that a lot of them would build their idea about how health insurance works from years of reading Reddit posts: They thought visiting the doctor was always going to be a $1000 bill or a single accident was going to medically bankrupt them, because those are the stories they saw on Reddit. I would explain things like the free annual physical and many just wouldn’t believe me. It’s really tough to cut through the confusion out there.
But if they do anything other than extremely basic tests, like blood pressure at the "free annual physical" you will be billed, ridiculous amounts you have no way of knowing in advance.
I would argue this has severe caveats. I knew a girl in college who was billed over 400$ to test for PCOS, which is one of those diseases that 1) affects just women 2) is underdiagnosed but has severe systemic effects like facial hair growth, diabetes and obesity...
I think you may be missing the point: preventative treatment is typically much less expensive, for instance behaviour and dietary changes do not require drugs at all and avoiding some conditions can be helped by drugs which have long since come off patents.
But even with your point, all insurance companies I've ever had cover with in the UK have had some element of support for preventing illness (periodic assessments, support material and trackers) and, at least with people covered under company schemes, they clearly have an incentive to offer more if you are at risk of becoming affected by a preventable illness.
So exercise, eating healthy, fasting, brushing/flossing teeth, consistent sleep schedule, daily sun exposure, good relationships, and stress management all depend on a health insurance plan?
You certainly need to "pay" for those yourself, insurance or not (I guess that's probably your point). Going for a run doesn't go on any billing schedule or contribute to GDP, it's all self-funded from your own personal resources of time and energy.
We pay either way. Pay to stay healthy or pay to stop being sick.
You only get so many chances to be sick before you can't come back from one, or it alters your life so severely you'd wish you were dead anyways.
I'll opt for paying to stay healthy.
Sam Vimes 'Boots' Theory of Socio-Economic Unfairness
>The reason that the rich were so rich, Vimes reasoned, was because they managed to spend less money.
>Take boots, for example. He earned thirty-eight dollars a month plus allowances. A really good pair of leather boots cost fifty dollars. But an affordable pair of boots, which were sort of OK for a season or two and then leaked like hell when the cardboard gave out, cost about ten dollars. Those were the kind of boots Vimes always bought, and wore until the soles were so thin that he could tell where he was in Ankh-Morpork on a foggy night by the feel of the cobbles.
>But the thing was that good boots lasted for years and years. A man who could afford fifty dollars had a pair of boots that’d still be keeping his feet dry in ten years’ time, while the poor man who could only afford cheap boots would have spent a hundred dollars on boots in the same time and would still have wet feet.
If you’re looking for the archive link in the comments like I was, it’s at the top underneath the original link.
It’s interesting they make no mention of trying to understand the body’s ability to self-defend and self-heal. That is, it’s possible to get X (e.g., cancer) and the immune system wins the fight (before it’s even detected).
In theory it’s possible the best early treatment is no treatment at all; that there might be such a thing as too-early detection.
This is a well known phenomenon in medicine. It is always carefully considered when making public health decisions regarding e.g. screening programs and intervention best practices.
For example, a PSA test is useful to detect cancer of the prostate, if a male patient has urination problems. But doing general screening for high PSA values in middle aged men is not considered a good idea, because there are too many false positives and it would likely lead to many unnecessary invasive interventions.
It's also why "early detection leads to longer survival" claims in cancer patients has to be treated with quite some care.
Two people develop a fatal cancer at T0. One is diagnosed at T1, the other at T2, both die at T3.
It looks like the first person survived longer with cancer than the second, but they didn't: the interventions had no effect, it's just a statistical artifact.
This is by no means always the case - earlier detected cancer is more treatable - but it still needs to be controlled for.
Have a friend working as urology surgeon - basically all men get prostate cancer, its just a function of time (unless you die young). Most of them is benign, or cause few issues and are often let alone.
If you would run scans on all males above say 45 there would be endless stream of operations happening, all of which would lower quality of life for everybody, and sometimes shorten their lives a bit or a bit more. Any public healthcare system would be brought to the edge of collapse by just this since surgeries are supremely expensive everywhere, that's not just US invention.
Yo, personal experience. I'll be undergoing a second test soon, as a precaution, but the first showed me at "acceptable risk level but cancer is still present".
My urologist carefully assured me ahead of the test that I "do have cancer, as all men my age do", and clarified the difference between "have" and "might well die of".
True for many things. You can have the HIV virus in your blood, and successfully fight it off, preventing infection. Your immune system will remember, and thereafter show markers that are indicate "possibly infected" - but you will not be CURRENTLY infected.
thats a cool study.
there should be more like it. (thanks for the archive link btw!)
Great study
Dis-eases that are symptoms ... of ... what?
Take hold?
Like they just float in there out of the blue and possess your body? Or like the habits that caused the dis-ease took hold?
It's a good thing all those dis-ease tests are 100% accurate and you can trust the manufacturers to not exaggerate and they are not trying to sell you treatments just for symptoms that can have any number of causes.
No responses just ragey downvotes? heh. keep em coming kids.
I though HN readers were supposed to be logical?
So I just pick a latin name for some symptoms and call that a dis-ease and it will rain money on me? Bonus points for a test that produces false positives at a high rate.
Poison the well and sell them fake cures -- best business model ever!
Personally, I don't find it helpful to post paywalled content here, at least without a summary. Other than that I'm here to for the kind of nerdy tech stuff that normally doesn't appear on NYT, Bloomberg etc which are designed to service adtech more than illuminate its consumers. I do consume their content, especially the latter but to me posting that stuff here feels like coming to a small downtown art gallery to discuss a prime time tv show like Big Brother or Friends reruns