As an adolescent around 1990, I burst my spleen in the final minutes of a school ski trip. Nearly bled to death as the school staff transported me home and left me in my living room to be found later by my parents nearly unconscious.
Anyway, I got to the emergency room that evening and there was much debate whether to remove my spleen. They decided not to and instead kept me hospitalized for 10 days and then out of school for 3 more weeks after that waiting for it to heal on its own.
Hi! Nice to meet you! Similar story! I was on a university research trip in the Philippians when my spleen spontaneously ruptured. It took 4 days to get home and by the time I got back to States for diagnosis half my blood was in my belly area... I rejected surgery since it had been days since initial event and healed on my own...
There’s another interesting spleen fact that I remember reading: people who survive flight ejections and hitting water at high speed tend to have had their spleens removed.
Probably because otherwise the impact causes a rupture and you bleed out too quickly to survive.
This does come up in the story of Cliff Judkins, a Marine Corps pilot who, in 1963, survived a fall of 15,000 feet into the Pacific Ocean. He had had his spleen removed a few years earlier, and a doctor told him that was probably a factor in his not being killed by the impact. Judkins' account is worth a read:
Thank you for sharing such an incredible story - I would never have expected to read something so entertaining in the comments of a post about mouse splenectomies.
What do you mean by “flight ejections”? Are we talking about ejection seat activations in military aircraft?
This factoid sounds very suspect. Doesn’t most people who need to activate an ejection seat survive spleen or no spleen? Deaths may occur of course, an ejection is not without risks, but if everyone or nearly everyone with a spleen dies then my understanding of the risk associated with an ejection is seriously miscalibrated.
Also the group of “active military pilots who had their spleen removed” must be a small group, likewise “military pilot who needed to activate an ejection seat” is a small group (but probably a bigger one than the spleenless group). So one would expect that there is almost nobody in the intersection of these two rarefied sets.
Obviously this is all very handwavy reasoning, so who knows. But if you have a source that would be highly appreciated.
Ejection seats are likely to cause spinal fractures (20~30% by one study) and broken legs (no numbers). Tests on the F-35 showed lighter pilots could have their necks broken by the heavier helmet, so they had to add a switch that will slow down the ejection sequence.
The risk of injury in ejection is quite a bit higher than most people expect (typically over 25% towards 50% for older tech ejection seats). It’s still a way better scenario than riding it in.
It is not uncommon for an ejection to end a pilot’s tactical jet flying days for medical reasons.
> It is not uncommon for an ejection to end a pilot’s tactical jet flying days for medical reasons.
This exact thing happened to a friend of mine. Combat-rated Harrier pilot in the RAF. Had to punch out after a bird strike. Came out of the infirmary 4 months later, 1/2 inch shorter, flying career over.
> The risk of injury in ejection is quite a bit higher than most people expect
I agree with you on that. But the question here is risk of death, not risk of injury.
I don’t have reliable statistics but found this[1] article which says about ejections: “If you look at statistics around the world, the survival rate is greater than 92 per cent.”
Obviously if you're ejecting at or near supersonic speeds there are other stresses, but if the trauma is mainly from the ejection booster itself why is it still done with such force?
It seems like a majority of ejections shouldn't be benefited by half a second less time to achieve clearance (or the jet itself could detect altitude and adjust the speed to increase survivability).
I'm guessing this is also a function of trying to achieve lateral separation from the ensuing fireball in a crash but it surprises me rates are so high for injury.
A cleverer ejection seat could track the tail and body of the craft, and adjust the rocket force based on the trajectories in each case.
Then you don't have to use enough force to avoid the tail in every case, but merely enough force to avoid the tail in this case, which will normally be far less.
An ejection seat is basically a rather powerful small rocket with huge acceleration - much more forceful than what astronauts nowadays experience. Human bodies aren't built for riding such rockets. Injuries from ejections are pretty common and some of the ejectees are never fit to be combat pilots again.
Yes, ejections are violent. Can cause injury, can cause death. No question about that.
Spinal injuries are likely and ejections frequently end the flying career of pilots for medical reasons.
What does this have to do with the claim in question?
They claimed “people who survive flight ejections and hitting water at high speed tend to have had their spleens removed”
This implies that if you look at the group of people who survived a flight ejection (over water and hit the water at high speed) you would find that most have no spleen. Do you find this plausible?
A trauma surgeon would be a better fit to answer that question, but crushed spleens seem to be common in high speed impacts (car crashes, falls from ladders etc.), at least as far as I can judge it from my limited circle of friends who have had such experience.
I honestly expected this article to be about the other meaning of spleen, a melancholy or depressive longing (as in Baudelaire’s “Le spleen de Paris”). Something about looking forward, giving up old spleens, etc.
Instead it’s genuinely interesting information about how an organ changes over time.
The premise of this article is based on a single study in 1969 on mice. I agree with the general premise that the immune system ages and becomes less effective as we get older, but will need more convincing that removing the spleen will make you live longer.
IIRC a lot of our data about human splenectomy comes from World War II, where it was performed often enough that some long term followups were possible with sufficiently large n
I've been without a spleen for longer than I had one. I wonder if -- if any of this translates to humans -- spleens are beneficial to the young but a risk to the old, meaning that since I survived my youth without, it's all good going forward; or if young spleens give long-lasting benefits, meaning that the best course is to have the spleen into old age, but then jettison it later in life (than I did).
Hi, fellow spleenless person. Make sure to look into the meningitis vaccines, too; there are multiple types of those now, and some only came in the market within the past few years. Also, if you give birth, your doctor may want to put you on prophylactic antibiotics while in labor or shortly thereafter.
A gorgeously illustrated deep dive into the immune system that will forever change how you think about your body, from the creator of the popular science YouTube channel Kurzgesagt—In a Nutshell
Immune: A Journey into the Mysterious System That Keeps You Alive
Huh. Well, this is interesting. As someone who’s been sans spleen since age eight, all I ever heard or read about was my risk for minor bacterial infections to potentially turn into overwhelming sepsis. I was put on penicillin VK 250 mg twice a day prophylactically from the time of my splenectomy until age seventeen, when I transferred to an adult primary care physician instead of my pediatrician. I have to get the pneumovax (which protects against multiple strains of bacterial pneumonia) every five years. And I’m still constantly figuring out if I’m truly up-to-date on all my other vaccines, because some of them (like the new multiple flavors of meningitis vaccines) didn’t exist when I was younger. In short, I’ve also associated my lack-of-spleen with hypervigilance about health, and not as a potential benefit as this article posits.
Also, splenectomy led to some fun times during the pandemic because it was and is somewhat unclear whether being permanently immune-compromised due to a splenectomy applied really only to bacteria and sepsis risk, or possibly to virii like coronovairus too, since antibodies and the things that help you “clear” an infection (including a viral infection?) are also produced in your spleen. In the UK, having had a splenectomy was explicitly listed as a condition for what they called “shielding” during the worst of the pandemic, but in the US it was not considered to be a condition named for early access to a full third dose (rather than a booster) of the vaccine.
Other side effects, not mentioned in this article:
- I now have enormous tonsils, to the point where my uvula hangs at a 45 degree angle, probably because the tonsils are making up for the spleen loss, since they serve a somewhat similar function.
- As another commenter here notes, we basically only have long-term data on splenectomized people’s outcomes because of WWII. The small risk of quick sepsis is always going to be there, and did impact their lifespan. But we don’t have enough recent data, in an age of more available antibiotics, to say if there are other potential problems to look for.
- As for histamine/allergy or autoimmune issues being lessened in mice without spleens —- well, I have the same annoying allergies as everyone else in my family, take Claritin daily, and developed auto-immune antibodies due to celiac and then got the oft-associated thyroid problems. So, a sample size of one here, but a splenectomy didn’t seem to be protective against either of those immune-related outcomes here.
All that being said, I don’t miss having a spleen. It was breaking down my entire (congenitally somewhat mishapen) red blood cell supply as a kid, like a swimming pool filter run amuck, leading to anemia and exhaustion and pallor. And while removing it did not make my blood cells gain a normal shape and size, it completely changed my quality of life.
Mine was removed in my twenties. I got the recommendation for pneumovax, and the warning about sudden overwhelming infection, but other than that, nothing too serious.
I think it is obvious at this point that the human body is designed to self-destruct, causing death at old age, once a certain biological threshold is reached. Resistance to this idea comes not from a rational perspective, but a semi-religious belief that your own body would not betray you.
It's odd to claim that's obvious when there are alternative explanations - the body is simply not all that optimized for old age because it isn't as much of a priority for passing genes and if such a complex system isn't optimized for it things are bound to give out.
The programmed aging theory may be "obvious" but there is not really evidence to support it as of the present.
If true, it would likely be very easy to stop aging (there would likely be some mechanism in cells causing aging that could simply be switched off), but this has not been borne out by research so far, and this is despite the fact that much anti-aging researching assumes it to be true.
The preponderance of the evidence currently seems to support the theory that aging is caused by damage building up over a lifetime.
I don’t think it is at all necessarily true that there would be one mechanism for programmed aging that could be disabled by modern medicine. Rather, evolutionary pressures might cause many mechanisms to develop simultaneously to prevent aging of individuals too far beyond the point of reproductive viability.
If aging is caused by built-up damage, how would babies ever come to exist and live normal lifespans? The cell lines that produce new human embryos are millions of years old, yet each newly born human doesn’t face the problems of old age until they are 40+ years old.
There's a strong filtering process. You're ignoring all the people, fetuses, embryos, and gametes that never pass on their genes.
When genomic damage gets too significant, and damage occurs to critical genes, individuals do not survive to reproductive age, fetuses are miscarried and aren't born, or embryonic development breaks and it might not even be known that fertilization occurred.
Aren't there also mechanisms that reduce accumulation of genetic damage in gametes compared to the rest of the body? That helps too.
I don't understand the proposed mechanism of evolutionary pressure here.
Evolutionary pressure can result in traits being selected over others because the individuals with the un-selected traits frequently fail to pass them on. But the cause and effect isn't so much "we need to survive this, let's devise an adaptation," it's "a certain trait happened to end up providing an advantage." There isn't an intentional aspect to the randomness of genetics.
Why and how would evolution - random mutation and selection pressures - penalize the long-lived? Many past cultures actually did the opposite, and elevated and respected elders, for their roles as knowledge holders and such. So how would being longer lived cause your progeny - who at that point would already be born - to be less prolific?
If groups with many longer lived members suffered a disadvantage then natural selection would favor dying earlier, but not too early. You have to think about survival of genes in groups, not just individual survival.
FWIW my guess is it just didn't matter much. Surviving to 50 was plenty enough to have offspring yet not so long you compete with you grandkids for resources or become too much of a burden. That's already much much longer than most species so if anything evolution has already optimized humans to live fairly long lives. Once that got to be "long enough" there just wasn't enough selective pressure to matter.
The human genome is clearly extremely well preserved and is has not changed all that much in hundreds of thousands of years.
However for an individual human, damage to tissues occurs.
For example, if you lose a tooth, it is not going to grow back even though you still have "tooth genes". And this damage is happening to every system of the body e.g. pretty much everybody has atherosclerosis and eventually all humans will die from it if they live long enough.
To increase human lifespan we have to fix all of this entropic damage, which is not impossible but requires advances in medical technology, such as growing new tissue to replace damaged tissue.
One end of the spectrum of reasonable possibilities is that evolution selected for genes that cause and or favor death the older an organism gets, through implicit mechanisms like lack of regenerative capacity, such as heart tissue, or explicit mechanisms, of which I'm not aware of any. Are there any genes that explicitly produce a timing mechanism, and thereby create a built-in notion of aging?
To my knowledge, it's all implicit, resulting from wear and tear, the gradual degradation of DNA because of the nature of chemistry on the surface of the planet, and not because any gene or biological mechanism moves an organism through some programmatic notion of mortality.
This seems true to the extent that given molecular level control of an organism, current knowledge would be sufficient to maintain lifespan to an arbitrary degree. Barring sci-fi nanotechnology, genetics and anti-aging have to figure out more robust repair and damage prevention to extend lifespan.
> Are there any genes that explicitly produce a timing mechanism, and thereby create a built-in notion of aging?
Yes, telomeres.
Telomeres set a count on how many times a cell can divide before it ceases to divide and becoming old and useless; in humans, the count is 40-60 divisions and then the cell essentially dies.
There may be other timing mechanisms that haven't been discovered as well.
It's less of a timing and more like of a "TTL" of a network packet. If you don't divide you don't use them up, even if you could live a thousand years. If you keep dividing like crazy, it will eventually reach useful DNA and the cell will die.
They seem to be quite specifically an anti-cancer measure.
I've wondered what kinds of things we're doing both good and bad to our bodies.
For example, with modern society food availability is high. For example we could eat kale every day. Starving is optional. yet I've read that fasting is the way to metabolize senescent cells, but maybe nobody does it anymore.
I wouldn’t say self destruct, your body and your child’s body and your grandchild’s body are all a continuation of the same organism. Selection favors clearing out the old dead mutated cells and that is just extending to bodies as well. If we conceptualize ourselves as separate from our descendents, we think we’re dying, but if we procreate our cell line lives on, which is the only outcome which matters to evolution.
There's little incentive for the repair processes to be perfect. There would actually be zero incentive after we reproduce - and some species are exactly like that. The moment you reproduce, you die.
Humans, being a social species, might have pushed evolution towards trying to repair a bit more than it should. Older humans can still contribute - sometimes a lot - to the group. Older males can still reproduce in many cases.
Evolution's natural selection looses it's power after ones child reached maturity. It's now up to our frontal lobe to keep on improving our bodies.
With that said, it's possible that long life might have negative effect on resource availability which might affect procreation and child rearing, and might find shorter life-span more advantageous to survival of species.
I think this is a fair point. We're multicellular life forms. We're not 1 living thing, but rather a collection of many living things working together. It could be that some of those living things start to betray each other (for personal gain) which aids in our demise. Just as individual humans can do the same to each other, leading to society's demise. But I'm not sure that means we were designed to self-destruct.
Why is that “obvious” and why is the “other” side the religious one and not your “design” assertion?
I’m not an expert on such subjects but it seems more closely related to the concepts of evolution to say natural selection does not show preference for abnormally long lived individuals because it is unknown or unimportant at time of procreation which traits lead towards lifetime longevity beyond short term hunter gatherer traits.
Under the traditional view, the most evolutionarily advantageous individual is one that lives forever and continues to spread their genes indefinitely, producing hundreds of offspring. Why is this not what we see in practice?
I think it's because, we would live forever, but something goes awry after being mature for so long that our bodies haven't evolved far enough to counteract yet. We solve this by sexually reproducing, which resets the clock on age, so our cell line is still able to live on. We do this instead of resetting our mature bodies because reseting 1 or few cells is easier than resetting/replacing billions that are dysfunctional. So we sorta evolved on the path of least resistance required to live forever, and require further evolution before our mature bodies can do the same, so to speak.
There's no advantage to having a single individual who lives and reproduces forever compared to having his offspring, and his offspring's offspring, etc. reproduce forever.
This way of thinking is dangerous. This is like saying that there is "planned obsolescence" when in reality products are designed to last a certain period. They are not designed to fail after that period but they are also not designed to last longer than that period. The end result is similar but the intention is totally different.
It's hard to survive in the presence of a constant onslaught of forces trying to break you down. Plus we have another way of surviving: multiplying. And multiplying gives us mutations as well, i.e better fitness. So why should our organism optimize for longlivety?
Anyway, I got to the emergency room that evening and there was much debate whether to remove my spleen. They decided not to and instead kept me hospitalized for 10 days and then out of school for 3 more weeks after that waiting for it to heal on its own.