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Are Japanese Intestines Longer?
- alexweberk 11y agoI feel betrayed. I want a clear answer!
- stinos 11y agoYou could try at http://skeptics.stackexchange.com/ http://skeptics.stackexchange.com/
- cpncrunch 11y agohttp://www.ncbi.nlm.nih.gov/pubmed/8568407 http://www.ncbi.nlm.nih.gov/pubmed/8568407
- jpatokal 11y agoAlready asked: http://skeptics.stackexchange.com/questions/18385/do-asian-esp-japanese-people-have-longer-intestines-than-people-of-european-d http://skeptics.stackexchange.com/questions/18385/do-asian-e... The only answer proffered doesn't actually answer the question, though.
- andyraskin 11y agoJoin the club!
- chanind 11y agoWhen 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 11y ago> 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.
- sliverstorm 11y agoA photo from an event at the Korean DMZ: http://i.imgur.com/aHsayNH.png http://i.imgur.com/aHsayNH.png From left to right, American, North Korean, South Korean. A empirical illustration of both the role of genetic factors (American vs. South Korean) and the role of non-genetic factors (South Korean vs. North Korean)
- jrochkind1 11y agoI don't believe empirical means what you think it means. Perhaps you mean 'anecdotal'.
- sliverstorm 11y agobased on, concerned with, or verifiable by observation... It's a tiny sample of empirical evidence to be sure.
- mkempe 11y agoThe US army specifically picks tall soldiers for the DMZ. I heard about it in the 70s.
- sliverstorm 11y agoIn the context of this discussion, it's really the NK vs. SK soldier that is interesting. The people of both N. & S. Korea are pretty close genetically, and presumably NK does not send their shrimps.
- pavel_lishin 11y agoThis 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 11y agoFrom 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?
- pavel_lishin 11y ago> Also, do you correct for body length, for body volume, or for neither? Start by doing none of the above, but simply measuring the intestines, and recording the data, along with all the things you mentioned above. Statistical analyses can be done after, to see if there's anything interesting in the data at all. Not sure how to address the tension question; I guess ideally, you'd have someone fly around to Japan and a few other countries, and demonstrate some arbitrary method of measurement. But that starts to get expensive.
- yummyfajitas 11y agoThe statistical analysis to be done should be decided before looking at the data. http://www.stat.columbia.edu/~gelman/research/unpublished/p_hacking.pdf http://www.stat.columbia.edu/~gelman/research/unpublished/p_... Blinding should be pretty easy and cheap - have an assistant cover up the head with a sheet as the measurement is made.
- Someone 11y ago"Blinding should be pretty easy and cheap - have an assistant cover up the head with a sheet as the measurement is made." But you would need to move the body, or have an experimenter who doesn't know whether he is in Japan (using Japanese living abroad or westerners living in Japan for the experiment is for the follow-up study) Also, but that's relatively minor, covering the head is insufficient. There are lots of other cues, such as skin color, tattoos, missing little fingers, body size, etc. that correlate well with being Japanese as opposed to being a westerner. I would have the assistant cut out everything from the stomach down (even though there is a sphincter, if the size difference is small, specifying where the intestines start will be a challenge) and empty it before handing it over to the experimenter (indirectly, to prevent communication between assistant and experimenters)
- weatherlight 11y agoThis is definitely the most surreal article I've ever read on HN....And I think I liked it.
- legohead 11y agoAgreed.. I have a 6 year old daughter who refuses to eat meat, and now I'm wondering if she has really long intestines.
- ThinkingGuy 11y agoI 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.
- Thriptic 11y agoI 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/annsurg01359-0189.pdf http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1513781/pdf/anns... 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%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 http://download.springer.com/static/pdf/803/art%253A10.1007%...
- deltaprotocol 11y agoYou 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.
- mih 11y agoAn 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?
- JacobAldridge 11y agoWell you just added 10 years and an awful lot more poorly-worded, awkward morgue conversations to Andy's follow-up research!
- zhemao 11y ago> 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 11y agoModern 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.
- jkyle 11y agoA 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.
- Justsignedup 11y agoQuestion: 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?
- Steko 11y agoThe 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.
- gohrt 11y agoIt's also a very scary and dangerous phenomenon -- that was one of the major historical lessons of the German side in WWII.
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- hangonhn 11y agoA 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 11y agoThat'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 11y agoYou sure that's because she's Japanese? I'm not Japanese and my body temp is lower on average.
- yellowapple 11y agoI'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 11y agoYes, 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-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 http://www.quora.com/Do-Japanese-people-or-other-people-from...
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- stefantalpalaru 11y agoThe author refers to the small and large intestine interchangeably and this kind of confusion is no way to start your research.
- slyall 11y agoI 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.
- jerf 11y agoA 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.)
- gohrt 11y agoNot necessarily relevant to meat, but, if your intestines are too long, then you might be at risk for over-digesting something , dehydrating it into a hard mass that is difficult for the rest of the sytem to process.
- lnanek2 11y agoIt'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.
- cpncrunch 11y agoWhat 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.
- freemore 11y agoThis 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.
- freemore 11y agoIn 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.