Are Japanese Intestines Longer?

Notes from my 30-year quest.


Contestant Number One in the Japan Society of New York’s 1993 Japanese Speech Competition was a Puerto Rican man in his early twenties who had played baseball at a Tokyo high school. In impressively accented Japanese, he bragged about fitting in so well that his teammates called him Taro, a common boy’s name. He compared himself to Tom Selleck’s character in Mr. Baseball, a movie about an American who plays for a Japanese team.

Contestant Number Two that year was a blonde woman who demonstrated considerable knowledge of flower arranging and tea ceremony. Her accent needed work, as did her use of polite forms.

Contestant Number Three began by asking the standing-room-only audience, “Nihon-jin no cho to America-jin no cho to de wa, nani ka, chigai ga arimasu ka?”

Is there any difference between Japanese people’s intestines and American people’s intestines?

Big laugh from the crowd. And that would cost me.

I was Contestant Number Three.


I grew up believing that, aside from surface characteristics and susceptibility to certain diseases, members of the human race are the same. This belief was reinforced by many hours watching Sesame Street and listening to Free To Be You and Me.

The first person in my life to challenge this view was a puffy-cheeked 28-year-old woman named Ms. Yamada. The year I studied Japanese at a university in Tokyo, Ms. Yamada was my reading teacher. Every day, she cut out a Japanese newspaper article for our class to translate. One day, the article she cut out was about the Beef and Orange Trade Problem.

That year, everyone in Japan was talking about the Beef and Orange Trade Problem. The problem, according to the United States, was that Japan imposed high tariffs on American meat and fruit. The problem according to Japan, was that the United States thought there was a problem.

Ms. Yamada led us through a character-by-character dissection of the article, which summarized the positions of the respective governments. There wasn’t much I hadn’t heard before, until we got to a quote near the end. It was attributed to Tsutomu Hata, Japan’s then-minister of agriculture:

The reason why the Japanese can’t import more beef is because Japanese intestines are longer than those of Americans. We’re not as good at digesting meat.

A German girl named Astrid pointed to her abdomen. “He’s talking about these?”

Ms. Yamada nodded.

“And yours,” Astrid said, “are longer?”

From the look on Ms. Yamada’s face, Astrid might as well have asked if the sky was really blue.

“Doesn’t everyone know that?” Ms. Yamada said.


Free to Be You and Me never explicitly said that on the level of internal organs we’re all interchangeable, but to my mind it was implied.

So I set out to investigate Ms. Yamada’s assertion. Over the next few weeks, I asked Japanese students on our Tokyo campus if there were any differences between their intestines and mine. In a notebook, I jotted down the responses:

“Yes. Japanese intestines are longer.”

“Japanese intestines are much longer.”

“Never heard that.”

“Japanese intestines are exactly 1.5 times longer.”

“Who told you that?”

These initial answers were statistically similar to those I eventually gathered from a total of 120 students. Overall, 65 percent believed that Japanese intestines were longer. I heard the suspiciously precise “1.5” four times.

A junior on the men’s soccer team told me that because Japanese intestines are longer—sorry, there’s no delicate way to translate this—Japanese people excrete a higher volume of feces. The Japanese were so prolific in this way, he said, that one reason the Allies were victorious in World War II was that it was easy to spot hidden Japanese troops simply by searching for extra-high piles of human dung.

To be fair, he cautioned that he wasn’t 100% sure if that last part was true.

Thirty-five percent of the Japanese students I asked had never heard of the intestinal difference. But when I encountered students who said their intestines were indeed longer, I always asked if they knew why.

“We Japanese were traditionally an agricultural people,” one male explained. “Our ancestors didn’t eat much meat, so we evolved a longer intestine to digest the vegetables. You know, like how cows need multiple stomachs to digest roughage.”

I heard that answer a lot. There was something about it that seemed plausible, but I also detected an air of superiority in it. It positioned outsiders as carnivores—aggressive, lion-like hunters who were lazy most of the time (digesting meat). The Japanese, on the other hand, were grazers, always chewing, always working. Maybe I was just sensitive: Japan’s economic success had a way of making you feel inferior back then.

Certainly, though, the “agricultural people” explanation had holes. First of all, the identity of modern Japanese people’s ancestors is the great unanswered question of Japanese archaeology. (Much evidence points to the politically unwelcome conclusion that they came from the Korean peninsula.)

Second, although many non-Japanese eat a lot of meat, our ancestors—is it even possible to generalize about “our” ancestors?—probably ate less. And then there’s the idea that intestinal length varies inversely in proportion to carnivorousness, and that changes take place over just a few generations.

Or faster: One woman I spoke to hypothesized that when Japanese exchange students returned from a year living (and eating) in the United States, they would find that their intestines had shrunk.

Luckily I got involved with other things, and for a few years I didn’t think much about Japanese intestines.


Five years later, though, I was studying Japanese again, this time as a graduate student at the University of Pennsylvania. One of my teachers told me about the Japan Society’s speech contest and its theme: “The Uniqueness of the Japanese People.”

To prepare for the speech contest, I did some follow-on research. The first person I called was Hiromi Shinya, a Japanese-born gastroenterologist who worked at Mount Sinai Hospital in New York City.

I had met Dr. Shinya a few years earlier, when I was working as a production coordinator for Japanese TV programs. A variety show had hired me to produce a segment about an aging Japanese comedian’s Manhattan vacation, which happened to include a colonoscopy performed by Dr. Shinya. (A video of the comedian’s cancer-free colon was later broadcast on Japanese TV.)

Unfortunately, when I called Dr. Shinya before the speech contest, his assistant told me that he had a strict policy against speaking to press. I replied that I wasn’t press, but she said it didn’t matter. Instead, she recommended that I purchase Dr. Shinya’s new book, The Digestive Tract Speaks (Icho wa Kataru), at the Japanese bookstore in Rockefeller Center.

Part memoir, part guide to intestinal self-help, The Digestive Tract Speaks included Dr. Shinya’s reflections on his early days in the United States. This passage (my translation) caught my attention:

…when I looked at the intestines of Americans whose diet was primarily meat-based, I could hardly contain my astonishment. Their intestines were stiff and short… On the other hand, the intestines of people—even some Westerners—who subsisted entirely or primarily on a diet of grains, beans, vegetables and fruits, tended to be very smooth and relatively long. The latter type is common among Japanese people, and leads to a much better intestinal condition.

Dr. Shinya was suggesting that intestines get longer or shorter not due to evolution, but because of interactions with food that change the elasticity of tissue. That made sense to me. Still, he was asserting that Japanese intestines were, on average, longer.

Naturally, I wondered: Had anyone ever measured?


I had just been trained by the Penn library staff to search the university’s archives in Japanese, so I typed “Japanese intestines longer” in into the library’s Japanese search tool. Zero results.

Then I typed the same words in English. This time, there was one result.

A paper titled “The Length of the Intestine in Japanese” was housed at the Historical Medical Library at the College of Physicians of Philadelphia, which turned out to be a block from my apartment. The paper was a handwritten English translation of a German document penned by a physician named Henrich Botha Scheube. The manuscript was undated, but I found it in a box filled with other papers, all about Japanese physiology, that were dated between 1876 and 1889.

Dr. Scheube began by citing his hypothesis that Japanese intestines might be longer:

In my [previous paper,] ‘Remarks on the Japanese Diet,’” I said that very probably rice is better used up in the intestine of the Japanese than in that of the European, and I expressed a surmise that the Japanese intestine must be the longer of the two.

To test his “surmise,” Dr. Scheube measured the intestines of 26 Japanese cadavers between the ages of 17 and 60. He compared the data he collected to the typical length of intestines in Europeans, which he learned from a European anatomy textbook was between 800 and 900 centimeters. Here are his findings:

The 26 cases give a length of intestine of 953.7 cm. The maximum was 1203, the minimum 667; only 3 times the intestine was below 800…Accordingly, even the absolute length of the intestine is greater in the Japanese than in the European.

Dr. Scheube noted that the difference was even more striking when he considered the fact that, back then, an average European was 11 centimeters taller than an average Japanese. Relative to body length, he found that Japanese intestines were 20 percent longer.

He cautioned, however, that 26 intestines was not a lot to go on.

“Whether further measurements will confirm these conclusions,” he wrote, “remains to be seen.”


On the day of the speech contest, I took an Amtrak train from Philadelphia to New York, and then a cab to the Japan Society, which was not far from the United Nations.

At the podium, after voicing my thematic question about the length of Japanese intestines, I summarized what I’d learned from my survey and from the writings of Dr. Shinya and Dr. Scheube.

I also shared other beliefs I had encountered in Japan. One was about how the Japanese brain hears the buzzing of certain insects (typically cicadas) as music, whereas to the rest of us it’s just buzzing. Another was that when you ask a Japanese mother how long it takes from the time her baby is conceived until it’s born, she will invariably say 10 months.

I said that this last belief, about gestation, could be explained by Japan’s traditional use of the Chinese lunar calendar. In fact, Japanese and U.S. doctors agree that the human gestation period is 280 days(ten 28-day months).

Or—and this got the huge laugh I was hoping for—maybe Japanese babies just needed more time to grow their extra-long intestines.

Before announcing the results, the speech contest’s head judge — a bearded Japanese academic — said, “Mr. Raskin’s speech was quite funny.” At first I thought that was praise. Eventually I realized it was his explanation for why I didn’t win. Later he told me that I shouldn’t be talking about intestines at a speech contest.

The baseball player came in third, and I was runner up. The blonde woman with the bad accent won first prize — two round-trip tickets to Tokyo. The head judge said her answer to his question about her favorite Japanese season — “Spring, because the cherry blossoms are in bloom” — indicated she was the one who best understood the uniqueness of the Japanese people.


I thought I could move on from Japanese intestines after that, but no.

In 1995, when the Internet took off, the first thing I typed into Yahoo’s search engine was “Japanese intestines longer.” 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.

Then, in 2005, I met a Japanese gastroenterologist in Tokyo through a social connection, and I couldn’t help but try to tap his expertise. He told me that when he did colonoscopies in Japan, intestines were sometimes so long that he ran out of camera cable.

“I doubt the same thing happens in America,” he said.

I discounted his testimony as ludicrous until 2007, when symptoms I won’t elaborate on required me to seek the services of an American colorectal surgeon named Jeff Sternberg, in San Francisco. After my operation, I posed to Dr. Sternberg the question I had then been asking for 20 years.

“I don’t have any data or anything,” Dr. Sternberg said, “but it’s kind of known in the field that when you scope Asian woman — especially a young Asian woman — their colons are, like, really freakin’ long.”


It’s now been nearly 30 years since Ms. Yamada helped our class translate Minister Hata’s famous quote, yet I have no firm answer about its veracity. However, I at least know that I am not alone wanting one. Just today, I received this, out of the blue, from a man who read a post I wrote a while back on the subject:

Dear Mr. Raskin,
I met Mr. Hata, Minister of Agriculture at that time, in person and heard his intestines story again and again in all corners of Japan. As a 38-year veteran of Japan with agricultural connections (and German intestines), married to a Japanese half my weight who eats about the same as myself without the weight gains, I tend to think that there is some truth in Mr. Hata’s statement. …Why [today] does the Ministry of Agriculture, Forestry, and Fisheries of Japan promote wagyu all over the world — beef which, as you well know, is not much more than a chunk of animal fat. Is it because they don’t want to burden Japanese intestines with their own fatty beef? It seems that the intestines story is not over yet.

That last sentence, anyway, is probably true.