Do You Really Have a New Body Every 7 Years?

You may have heard the rumor. Every seven years your body becomes a whole new person. But is there anything to this? Check out this SciShow episode to find out!

Hosted by: Hank Green
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[ohzoee]

The only thing that mildly irritated me was the fact that a chicken drumstick fell into the stomach acid as he said 'chicken wing'

[NKracken]

I gonna become a new man

*waits 7 years

Still the same man :(

[WillyTheComposerOfficial]

In case you're wondering where the 7 years thing comes from, I read somewhere that it's the average life expectancy of cells, not the maximum age.

[PurlaneMauve]

In short: yes, but not all of it, like the brain and heart.

The ship of Theseus paradox applies very well to our bodies, apart from brain and heart tissue and what not.

EDIT: If in the Ship of Theseus you replace all of the ship except a few hooks and boards of the original ship, is it still the same ship?

[ErzengelDesLichtes]

0:30 "It's one of those internet myths." I remember hearing this myth from my middle-school science teacher back before the internet became a thing. Pretty sure I read about it in the textbooks, too, which were certainly twice my age at the time. So I don't think "internet myth" is entirely accurate.

[ChristieNel]

I get a new cybernetic body every 7 years, but then, I work for a top secret government agency that incorporates alien technology.

[Joeobrown]

next episode please - you know when you have a really good fart brewing, look forward to letting it out and is just dissolves into non-existence, what's going on there?

[InvitingShores]

I've always though this myth goes differently: not about the replacement of cells, but of atoms which make up those cells.

[arshan]

I expected your viewership to be a bit more educated than what I had a glance at in the section below.

[cheshrektten]

This feels very poetic.. like after a breakup you might be over them physically because everything they touched is replaced.. but your heart still hurts because it hasn't replaced the cells their personality touched (yet).

[zoobihan]

I love how detailed and thorough these videos are, it was really good that you mentioned biosex females, which many people tend to overlook. It's similar to how my geology teacher always says that dinosaurs are extinct, and I feel like shouting "no! Non-avian dinosaurs are extinct; avian dinosaurs are still very much alive! Just look at the pigeon outside!"

[Man_Toast]

You are reading yet another comment concerning the use of 'biosex' within this video. That is all, continue scrolling.

[Nosirrbro]

I find it really strange that the entire internet decided to make youtube videos about this topic right now xD

[MathHacker]

I see a lot of videos like this on this channel, where it says that it's debunking something, but when it goes into detail, it seems to mostly support it. While 7 years is really just arbitrary and there are some cells that aren't replaced, it sounds like your body does replace most of the matter in it over the long run, which is really the heart of the idea.

[B.W.Jackson]

I used to accept this myth as a comforting self-deception. I was really struggling at the time with my feeling of present identity vs. my (oh so unsavory) past. The thought that I could be absolutely new was a great feeling to me, allowing me to shed that past and move on. The truth is not troubling; I've worked since to establish more cogent and factual reasons not to be stuck with my missteps.

[shmowen]

All your cells may not be replaced, but the molecules that make up those cells are constantly being changed and exchanged. I wouldn't have the slightest idea how long it would take for you to be an entirely new set of molecules but I would imagine it happens more than once in a lifetime.

[bobbysafoyan]

Oooo 23 seconds old!! thats some fresh SciShow!!!

[Trekkifulshay]

If only I could regenerate my arthritis damaged joints.

[codyteach]

well I was interested in the video content, thanks scishow! This channel is one of my absolute favorites!

[BALAGE]

CGP Grey and Kurzgesagt also made videos about this topic. Coincidence?