# Every Atom in Your Body Is Replaced every 5 Years **URL:** \ **Category:** Factual Questions\ **Created:** [December 5, 2023, 8:43pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147 "2023-12-05T20:43:21Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [December 5, 2023, 8:43pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/1 "2023-12-05T20:43:21Z")
Or so I heard Michael from Vsauce say. Checking around it seems to be true: _“Studies at the Oak Ridge Atomic Research Center have revealed that about 98 percent of all the atoms in a human body are replaced every year. You get a new suit of skin every month and a new liver every six weeks. The lining of your stomach lasts only five days before it’s replaced. Even your bones are not the solid, stable, concrete-like things you might have thought them to be: They are undergoing constant change. The bones you have today are different from the bones you had a year ago. Experts in this area of research have concluded that there is a complete, 100 percent turnover of atoms in the body at least every five years. In other words, not one single atom present in your body today was there five years ago.”_ I have two questions; 1. Then why do we get diseases like cancer - from long term smoking or long years of exposure to the sun. If the lung atoms are being replaced it seems that should re-set the abrasion? 2. If the atoms that make up brain cells get replaced, how does our memory remain? Sorry if these are stupid questions, but on some level this doesn’t make sense. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [December 5, 2023, 8:59pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/2 "2023-12-05T20:59:37Z")
> [@Lucas\_Jackson](#): > > Then why do we get diseases like cancer - from long term smoking or long years of exposure to the sun. If the lung atoms are being replaced it seems that should re-set the abrasion? Cancer is a property of the DNA in your cells getting messed up and replicating endlessly. It’s a problem with the _structures_ formed out of atoms - the DNA. If you were to replace those atoms in place, you’d still have the same results. Same with memories. They are a property of the structures formed by your neurons, not a property of the atoms themselves. ---
**Author:** ![Pardel-Lux](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pardel-lux/32/20182_2.png) [@Pardel-Lux](https://boards.straightdope.com/u/Pardel-Lux)\ **Post date:** [December 5, 2023, 9:06pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/3 "2023-12-05T21:06:47Z")
Well first of all, it is not strictly true, on a very nitpicky way. As there are more molecules of water in your body than litres of water in the world, you have a couple of molecules of water that were drunk (or sweated or pissed) by any historical person you wish to think about, provided they lived long ago and the water has had the time to mix well “enough” with the rest of the water in the world. So a couple of molecules of water and calcium atoms in your bones will still be there, only in a different place. There was a thread about that. Then the memory and the cancer due to smoking: it is a variant of the [Ship of Thesseus](https://en.wikipedia.org/wiki/Ship_of_Theseus) paradox: The atoms may not be the same, but the damage done to the structure of the cell and it’s DNA and RNA by cancerigenous substances remains when you swap the atoms one by one in the same location, and the memory is due to things like synapses, their number and strength, action potentials, and much more (it is really complicated, I don’t think experts understand it completely), but those things remain invariant swapping single atoms one at a time, one after the other. And sometimes you forget things, and some smokers do not develop cancer (yet). ---
**Author:** ![Pardel-Lux](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pardel-lux/32/20182_2.png) [@Pardel-Lux](https://boards.straightdope.com/u/Pardel-Lux)\ **Post date:** [December 5, 2023, 9:08pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/4 "2023-12-05T21:08:51Z")
Here it is: > [@Water Molecules and Christopher Columbus](https://boards.straightdope.com/t/water-molecules-and-christopher-columbus/452307): > > I remember something from my childhood that I am trying to confirm. I was told that if Christopher Columbus had dumped a cup of water in the ocean, any cup of water taken from any ocean today would have at least 250 molecules from the original cup of water Columbus dumped. Can this be true?! But there was another one later, that was even better. Can’t find it. My discourse-fu fails. That is the one I meant: > [@What is the possibility: You’ve peed a molecule of Titanic’s iceberg i](https://boards.straightdope.com/t/what-is-the-possibility-you-ve-peed-a-molecule-of-titanic-s-iceberg-i/950471): > > Assuming you live in eastern N America or western Europe and are over 30 years old? ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [December 5, 2023, 9:45pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/5 "2023-12-05T21:45:41Z")
> [@Lucas\_Jackson](#): > > Or so I heard Michael from Vsauce say. Vsauce is the Paul “The Rest…of the Story” Harvey of YouTube. Stranger ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [December 5, 2023, 10:03pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/6 "2023-12-05T22:03:33Z")
> [@Lucas\_Jackson](#): > > - Then why do we get diseases like cancer - from long term smoking or long years of exposure to the sun. If the lung atoms are being replaced it seems that should re-set the abrasion? > - If the atoms that make up brain cells get replaced, how does our memory remain? **“The beauty of a living thing is not the atoms that go into it, but the way those atoms are put together.”** -Carl Sagan As goes the beauty, so goes the suffering. Swap out one carbon atom in a cancer cell, and you’ve still got a cancer cell. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [December 5, 2023, 10:05pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/7 "2023-12-05T22:05:37Z")
> [@Lucas\_Jackson](#): > > Then why do we get diseases like cancer - from long term smoking or long years of exposure to the sun. If the lung atoms are being replaced it seems that should re-set the abrasion? Saying that every atom is “replaced” is a bit misleading. It doesn’t mean that individual atoms are replaced within persistent molecular/cellular structures (except in rare cases), nor that anyhing is “reset” to an original state. The hypothesis, if correct, surely just means that entire cells are dying and being replaced by new cells of the same type. The new cells will contain many “new” (to your body) atoms derived from food. Cells of the same type will be somewhat different from the old cells. In particular, making new cells involves DNA replication, so the new cells will contain mutations. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [December 5, 2023, 10:07pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/8 "2023-12-05T22:07:01Z")
It’s bullshit. E.g. check out the graph of strontium retention on Page 42: [https://journals.sagepub.com/doi/pdf/10.1016/S0074-27407380001-7](https://journals.sagepub.com/doi/pdf/10.1016/S0074-27407380001-7) plenty of atoms left even after 10000 days… ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [December 5, 2023, 10:08pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/9 "2023-12-05T22:08:06Z")
> [@DPRK](#): > > It’s bullshit. I always thought that it had been pretty much debunked for some cell types, notably neurons. ---
**Author:** ![Dr\_Paprika](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr_paprika/32/3042_2.png) [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)\ **Post date:** [December 6, 2023, 2:32am UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/10 "2023-12-06T02:32:29Z")
Just hope it means the warranty is stilll valid… ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [December 6, 2023, 2:49am UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/11 "2023-12-06T02:49:05Z")
> [@Lucas\_Jackson](#): > > “Studies at the Oak Ridge Atomic Research Center… Studies at the what? There is an Oak Ridge National Laboratory, but according to Wiki The topic being discussed here isn’t something they focus on. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [December 6, 2023, 3:36am UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/12 "2023-12-06T03:36:12Z")
Oak Ridge National Labs studies a wide range of topics. I’m not sure the name Oak Ridge Atomic Research Center is in use anywhere. [https://www.ornl.gov/group/molecular-and-cellular-imaging](https://www.ornl.gov/group/molecular-and-cellular-imaging) ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [December 6, 2023, 4:22am UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/13 "2023-12-06T04:22:39Z")
It seems like this is one those factoids that have been around a very long time. > **[Science: The Fleeting Flesh](https://content.time.com/time/subscriber/article/0,33009,936455,00.html)** > > About 98% of the atoms in the human body are renewed each year. This > surprising fact is discussed by Dr. Paul C. Aebersold of Oak Ridge in > the latest Annual Report of the Smithsonian Institution. Dr.... 1954 that date! Yes citing scientists at Oak Ridge. Who knows what the actual study was? ---
**Author:** ![Dissonance](https://avatars.discourse-cdn.com/v4/letter/d/85f322/32.png) [@Dissonance](https://boards.straightdope.com/u/Dissonance)\ **Post date:** [December 6, 2023, 4:54am UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/14 "2023-12-06T04:54:32Z")
The way that Times article is worded actually makes it sound like Oak Ridge is the city Dr. Paul C. Aebersold is from, not a national lab that he works at. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [December 6, 2023, 5:13am UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/15 "2023-12-06T05:13:49Z")
There was a peaceful town called Oak Ridge Where people lived in harmony ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [December 6, 2023, 5:16am UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/16 "2023-12-06T05:16:58Z")
The town existed for the lab. It was originally X10, a Manhattan Project site and the town was created to support the site. A history: > **[The top-secret laboratory | ORNL](https://www.ornl.gov/news/top-secret-laboratory)** > > Oak Ridge National Laboratory today is an open science laboratory that attracts thousands of scientists and engineers from around the globe each year. It began in the World War II Manhattan Project, which developed the first atomic bombs. In summer... Aebersold was part of the Manhattan Project. He tragically ended his life by jumping off a building in 1967. But he seemed to be the source of the factoid that has long outlived the stay of atoms in most bodies! ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [December 6, 2023, 5:17am UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/17 "2023-12-06T05:17:30Z")
> [@DSeid](#): > > 1954 that date! I think all the letters in that article must have been replaced several times over by now. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [December 6, 2023, 8:32am UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/18 "2023-12-06T08:32:14Z")
This seems to be one of the roots of the assertion. A guest lecture by Dr. Paul C. Aebersold in 1954. Page 22 for the meat of it > **[905976.pdf](https://www.osti.gov/opennet/servlets/purl/905976.pdf)** > > 1768.82 KB Still not a peer reviewed publication but gets close to the source. But here is perhaps the original. Mostly the same text. But a proper publication. Page 254 in the PDF. It’s a big document. > **[annualreportofbo1953smit.pdf](https://ia800906.us.archive.org/29/items/annualreportofbo1953smit/annualreportofbo1953smit.pdf)** > > 39.16 MB ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [December 6, 2023, 5:45pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/19 "2023-12-06T17:45:33Z")
> [@Stranger\_On\_A\_Train](#): > > Vsauce is the Paul “The Rest…of the Story” Harvey of YouTube. “Paul Harvey… Good day!” ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [December 6, 2023, 6:14pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/20 "2023-12-06T18:14:16Z")
Nice tracking down! FWIW Paul Harvey brings back found memories of the radio on in the car with my dad … Clearly the factoid is not exactly based on hard up to date evidence … but the point being made then is exactly the point discussed in answer to the op. [Next page](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147.md?page=2)