
Are Japanese Intestines Longer? - andyraskin
https://medium.com/unpublishable-elsewhere/are-japanese-intestines-longer-8a41ca3e7d89
======
Steko
The obsession with Japanese uniqueness (biological, cultural, linguistic,
geographic, sociological, psychological, etc.) became quite a cottage industry
in postwar Japan and is collectively referred to as _nihonjinron_ [1].

[1]
[https://en.wikipedia.org/wiki/Nihonjinron](https://en.wikipedia.org/wiki/Nihonjinron)

You'll find plenty of grains of truth in these works but also some really
bonkers pseudoscience ("Japanese are descended from a different set of
primates"). It's not a monolithic movement so much as a strain of thought that
can color mainstream works to varying degrees as well as popular opinion due
to decades of being bombarded with these factoids by Japanese media.

~~~
hangonhn
A friend of mine, who's Caucasian, was living in Japan and had to go to the
hospital once. The doctor asked him what the normal body temperature was for a
white person. The doctor didn't really believe him when he said it's the same
as the Japanese.

~~~
glandium
That's because it's not the same. When my japanese wife has the same body
temperature as mine, she has a (slight) fever. Edit: Conversely, my body
temperature when I have a slight fever would be considered serious.

~~~
greggman
You sure that's because she's Japanese? I'm not Japanese and my body temp is
lower on average.

~~~
glandium
Take it with a grain of salt because this is from a pharmaceutical group, but
this page claims the average body temperature of the Japanese was 36.89°C 50
years ago and that it was 36.20°C as of 2009. [http://www.sawai.co.jp/kenko-
suishinka/illness/200909-02.htm...](http://www.sawai.co.jp/kenko-
suishinka/illness/200909-02.html)

Edit: although, that might as well be due to the aging population. That said,
I have been told that my average (by France standards) temperature was "a
little high".

------
ThinkingGuy
I had always heard that the "longer intestines" story was a myth promoted by
the Japanese government during World War II, with the dual goal of promoting
the idea of Japanese "uniqueness/superiority" and of discouraging the
consumption of meat, which had become very scarce during wartime.

------
mih
An interesting article, which begs another question. Are the intestines of
Japanese bigger compared to those of neighbouring Asians - the Chinese and the
Koreans (from whom they apparently descended despite a reluctance to accept
this fact) ? This should answer the question of whether it's the genetics at
play or the diet itself.

Remember the American doctor mentioned Asian women and not Japanese.
Statistically speaking there is a higher chance that the woman with long
intestines happens to be Chinese. His comment also brings up another
interesting question as to whether the lengths of male and female intestine
are different. Why did he mention women specifically?

~~~
zhemao
> This should answer the question of whether it's the genetics at play or the
> diet itself

How exactly? Chinese, Koreans, and Japanese have both similar diets and
similar genetics.

~~~
kevin_thibedeau
Modern Japanese are an admixture of earlier aboriginals who populated the
islands first and an isolated group of later immigrants that was likely
distinct from other East Asian groups. There is plenty of room for them to
have unique phenotypes due to this.

~~~
maaku
Japanese and Koreans are basically the same people, genetically and
linguistically. At least among the consensus of non Japanese researchers.
Japanese uniqueness infects the humanities as well...

~~~
volaski
According to your definition of "same people", all English speaking caucasians
are the same people, genetically and linguistically.

~~~
91edec
Am I missing something?

English speaking countries: UK, Australia, New Zealand, USA, Canada. Last time
I checked they all came from the UK so are genetically the same. So his
definition is correct, friend.

~~~
volaski
Read the context, friend. The original comment this guy replied to was
pointing out that people may have different traits because of their exposed
environment even though they had same origins. Are we all same people since we
are all homo sapiens? Is a Japanese person whose great great grandfather was
an American "same people" as pure breed Japanese? What is "Same people"
anyway?

------
weatherlight
This is definitely the most surreal article I've ever read on HN....And I
think I liked it.

~~~
legohead
Agreed.. I have a 6 year old daughter who refuses to eat meat, and now I'm
wondering if she has really long intestines.

------
pavel_lishin
This seems like something that could be settled fairly trivially by a couple
of morticians' offices in the west, and in Japan, just by measuring the
intestines of the recently deceased for a few months.

~~~
Someone
From what I see in movies, intestines are fairly stretchy. Do you measure
without tension? How does one do that? Under 1g tension? What if that turns
out to make a difference because Japanese intestines are longer but harder to
stretch?

Also, do you correct for body length, for body volume, or for neither?

Because of that, it probably is best to do it double-blind. That would make
the experiment a lot more expensive.

It seems a sure-fire road to a Nobel prize (of the Ig variety), though, so why
hasn't this been done yet?

~~~
kazinator
To obtain a consistent measure of guts, they should be twisted, dried and
tuned to the G two octaves below middle C.

~~~
rhaps0dy
Wait, are you serious or not? that was pretty funny, but it sounds plausible
too.

~~~
fredley
If you're going to go for an IgNobel, go all out.

------
Thriptic
I was intrigued by this and did some very quick searching. Here is an article
from 1948 which suggests that dietary differences are responsible for longer
intestines in Japanese and Russians:

[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1513781/pdf/anns...](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1513781/pdf/annsurg01359-0189.pdf)

Here is a review which mentions several articles in which investigators looked
at intestinal length among westerners and Japanese, but the authors concluded
that it was difficult to perform direct comparisons due to differences in
measurement techniques.

[http://download.springer.com/static/pdf/803/art%253A10.1007%...](http://download.springer.com/static/pdf/803/art%253A10.1007%252Fs00384-002-0403-x.pdf?originUrl=http%3A%2F%2Flink.springer.com%2Farticle%2F10.1007%2Fs00384-002-0403-x&token2=exp=1440444635~acl=%2Fstatic%2Fpdf%2F803%2Fart%25253A10.1007%25252Fs00384-002-0403-x.pdf%3ForiginUrl%3Dhttp%253A%252F%252Flink.springer.com%252Farticle%252F10.1007%252Fs00384-002-0403-x*~hmac=8f6d7381fbf17c417e5efc6a8c15da477a37d739292b8537ed9dac4549b425fb)

~~~
deltaprotocol
You should definitely send that to the author. After reading the (very
enjoyable but inconclusive) article, I'm sure his 30 years quest could see
some more data and, well, some more decades.

------
chanind
When I was in Japan someone offhandedly told me that too, and I thought it was
strange. They said it as an explanation of why there aren't massively muscular
Japanese men walking around everywhere like there supposedly are in the US
(it's probably just because weight-lifting isn't as popular in Japan as in the
west).

~~~
JDiculous
> it's probably just because weight-lifting isn't as popular in Japan as in
> the west

Don't discount the role of genetics. Some people are just naturally larger,
others couldn't get large even if they tried. Although Japanese people would
no doubt be bigger if there was more of a weightlifting culture, they'd still
be slimmer than the average American.

~~~
coralreef
Diet probably has a role to play as well. Western diets generally seem to have
more protein.

~~~
gertef
Eastern vs Western diet is far less relevant than Bodybuilder vs non-
Bodybuilder diet.

------
jkyle
A really great read. But of all the inquiries and search results only a single
one smacked of anything but anecdote

    
    
      That led me to yet another Japanese doctor, a man who offered to 
      compare intestinal lengths printed in U.S. and Japanese medical 
      texts. According to him, they were pretty much the same.

------
jerf
A family member of mine with diagnosed Celiac, 50% Dutch 50% German, now
dreads his bi-yearly colonoscopies (as he has hit that age) as he has to be
fully put under for what is normally an outpatient procedure because his
intestines are now unusually long as a result of ~30-50 years of untreated,
unknown Celiac. The doctor apparently acted like this is not an unusual thing.
No other known factors would produce this result (i.e. my family is not
otherwise known for large intestines in the other family members of the
colonoscopy age).

This proves nothing specific about the Japanese, but does demonstrate that
apparently environmental factors can affect intestine length, and the relevant
medical communities consider this boring background knowledge rather than a
research topic or urban legend. It is likely in this family member's case that
the Celiac only kicked in fully in his 20s, so it is likely all the
"environmental factors" occurred in full adulthood (though it is hard to be
sure).

(I'm unclear on how long intestines make it _harder_ to digest meat, though.
Being overprovisioned for a task does not _generally_ make the task more
difficult. I'd find it more likely that it's simply a matter of gut flora
adapting to the local diet and not liking deviations. It's the same reason
vegetarians can think meat is bad for everybody because when _they_ eat a bit
of meat they have a bad, gassy reaction; their gut flora is not adapted for
it. (If meat _is_ indeed bad for everyone, that isn't why.) It is easy to be
correct about some fact and really, really wrong about the reason behind the
fact.)

~~~
lnanek2
It's well established that carnivores have much shorter intestinal tracts.
Meat is relatively easy to digest and simply doesn't need a long break down
and absorption process. So we know meat eaters don't need long intestines like
herbivores.

Now, as to your question about long intestines making it harder to digest
meat. They don't do that in exclusion, they make living at all more difficult,
and digesting meat is a sub task of living. Research a bit on all the
digestive troubles of horses and cows, colic and the like, and you'll find out
that massive, long systems of intestines and stomachs have a lot that can go
wrong and kill the animal.

Long intestines let the animal live off easier to catch food, yes, but there
are definite drawbacks.

------
alexweberk
I feel betrayed. I want a clear answer!

~~~
stinos
You could try at
[http://skeptics.stackexchange.com/](http://skeptics.stackexchange.com/)

~~~
cpncrunch
[http://www.ncbi.nlm.nih.gov/pubmed/8568407](http://www.ncbi.nlm.nih.gov/pubmed/8568407)

------
freemore
In fact, most of Japanese intestines are shorter than Americans' ones.

The length of intestines are not relating to their races. It's just relating
to their height and age.

In 1995, British and Japanese research institutes reported as 'International
Colorectal Disease'. In 2004, Tokyo University also reported similar subject.
Both reports completely denied the story like "Japanese intestines are 1.5x
longer".

I think many Japanese believe this kind of stories, it's because one Japanese
drug company made false advertisement to boost their products. After all, this
is Pseudoscience.

------
cpncrunch
What a ridiculous article. If you take the most cursory look you'll see that
the Japanese have the same length of colons as non-Japanese. While the story
itself is interesting, it's irritating that the author doesn't even bother
looking at the science.

~~~
whalabi
source?

~~~
cpncrunch
See my other comments here.

------
Justsignedup
Question: Do we know that there are any benefits of having longer or shorter
intestines? Is the decreasing of elasticity linked to any problems, or is it
just muscles that are more worked out and has no effect at all? Is there any
research done on the subject at all?

------
slyall
I remember reading a story (at least 20 years ago) that some women in Japan
were getting their intestine shortened in order to lighten their skin.

No ghits sorry but from memory once the intestine was shortened the skin
started to magically lighten.

------
freemore
This article is totally wrong. In 2004, Tokyo University sampled, and reported
in detail. Many Japanese believe this story though. The report completely
denied this story.

Japanese and Americans, there are no big differences.

------
yellowapple
I'm just going to assume that the answer is "no"; otherwise, the title would
be phrased as "Japanese intestines are longer" or "Japanese intestines _might_
be longer".

~~~
cpncrunch
Yes, a 30 second google search (which the author apparently didn't do) shows
that the answer is "no".

[http://www.quora.com/Do-Japanese-people-or-other-people-
from...](http://www.quora.com/Do-Japanese-people-or-other-people-from-Asia-
have-longer-intestines-or-a-differently-structured-digestive-system-than-
other-humans-out-there-that-might-change-how-they-handle-certain-
foods?share=1)

~~~
kahirsch
The answer on Quora doesn't give any sources.

~~~
cpncrunch
The second answer does.

~~~
kahirsch
Oh, I thought that was something unrelated because of the "related" links that
Quora put after the first answer.

It would have been nice if they had the small intestine, too.

------
stefantalpalaru
The author refers to the small and large intestine interchangeably and this
kind of confusion is no way to start your research.

