Does dietary fiber prevent suicide?


Surprising effect Mexican foods have


Mexico is known for hot cuisines made from corn, kidney bean and a wide variety of chili pepper. There is the view that those foods are one of factors responsible for the country’s extremely low rate of suicide. Koichiro Fujita, professor emeritus at Tokyo Medical and Dental University and an authority on infection and immunology, wrote in his book two years ago that dietary fiber richly contained in beans has an effect of reducing stress and creating an intracerebral substance which makes you feel happy. He said fewer Mexicans commit suicide because they take plenty of dietary fiber.



According to a list of suicide rates announced in 2015 by the World Health Organization (WHO), Mexico ranked 137th among the 170 countries covered while Japan placed 17th. Some 30,000 people annually commit suicide in Japan which is infamously known as a “suicide country”.



It is generally said that Latin races like Mexicans rarely commit suicide. That is perhaps because they are cheerful and bright by nature and feel less stress. The warm climate and the Christian belief that bans suicide may also be the reasons. It is interesting to know that their greater intake of dietary fiber comes along with those reasons.



According to the standard table of food composition released in 2015 by the Ministry of Education, Culture, Sports, Science and Technology, vegetables other than beans routinely eaten by Japanese people contain only 1.8 grams of dietary fiber per 100 grams whereas chickpea, lentil, kidney bean respectively contain 8, 17 and 13 grams of dietary fiber per 100 grams.



Frijoles refritos, served on a table with a cup of orange juisce
Frijoles refritos, served on a table with a cup of orange juisce

An average Mexican takes more than 50 grams of dietary fiber per day. What about Japanese? The Ministry of Health, Labor and Welfare advises Japanese males and females aged 18 or over to take at least 19 grams and 17 grams, respectively, per day. But it says both actually take only 12 grams per day on the average. This means Mexicans take four times more dietary fiber than Japanese.



There is a Mexican dish called “frijoles refritos”. Though little known to Japanese, it is an essential food for Mexicans. This is a pasty dish made with beans. They have it either by putting it on tortilla chips (made from corn flower) or rolling it with tortilla (pancake also made from corn flower) just like salsa which means “soybean sauce”. Frijoles refritos is indeed rich in dietary fiber. Why don’t you try it in dinner this evening to eke out your meager dietary fiber intake and ease your stress?


メキシコの豆料理の1つに「フリホーレス・レフリトス」という、我々日本人にはあまり馴染みのない料理がある。メキシコ人にとっては欠かせない料理だ。これは、豆をペースト状にしたもので、「大豆ソース」を意味するサルサと同じように、すりつぶしたトウモロコシでつくるトルティーヤチップスにつけたり、トルティーヤで巻いたりして食べる。食物繊維豊富なことは間違いない。食物繊維の足りないあなた。ストレスに悩むあなた。今夜はメキシコ料理を味わってみてはいかが。(Written by: Chika Sato)(佐藤千華)