The secret of longevity: Should we learn from the Japanese diet? -BBC News Chinese

In the 1990s, another nutrition researcher, Walter Willett (Walter Willett,) mentioned in one of his papers that Japanese people live an abnormally long life, and that very few people die from heart disease.

Since then, many research papers have begun to raise the question of whether Japanese people’s longevity is related to their diet. If so, should the rest of us who want to live a long life also add these foods to our purchase list?

Zhang Shu, an epidemiology researcher at Japan’s National Center for Geriatrics and Gerontology, pointed out that Japanese cuisine is a very broad concept. It is not and was never a sushi buffet.

Nevertheless, a recent review of 39 studies on the relationship between Japanese cuisine and health found that many studies have emphasized several commonalities: seafood, vegetables, soybeans, and soy products such as soy sauce, rice, and miso soup (also known as miso soup). soup).

Zhang Shu said that it is true that, in general, eating this diet is associated with fewer deaths from heart disease, but he said that it does not seem to be related to specific diseases such as cancer.

Interestingly, it also seems to be related to low overall mortality.

Tsuyoshi Tsuduki, associate professor of food and molecular biological sciences at Tohoku University in Japan, studied which aspect of Japanese cuisine might contribute to longevity.

In the beginning, Tsuzuki and his collaborators used national survey data to prepare two diet plans: one set represents Japanese food in the 1990s; the other set represents American food in the same period.

The researchers freeze-dried these foods and fed them to the mice for 3 consecutive weeks, and then carefully observed their health.

Interestingly, although the fat, protein and carbohydrates contained in the two kinds of meals are the same, the fat content in the abdomen and blood of the rats who ate the Japanese meal was lower.

This shows that the source of nutrition-for example, meat for fish, rice for wheat-is related to the final result.

Taking it a step further, the researchers summarized different versions of Japanese cuisine over the past 50 years or so, and looked at the changes in Japanese dining over time (especially in large cities, where food is increasingly influenced by the West).

Then, they formulated several different packages based on the national eating habits of 1960, 1975, 1990, and 2005. They cooked and freeze-dried these foods before feeding them to rats. The next step is to observe these rodents in large numbers. This time the test lasted for 8 months.

It turns out that not all Japanese meals have the same effect.

For example, the risk of diabetes and fatty liver disease in these little mice who ate the 1975 meal was lower than that of other mice. When scientists examined their livers, they found that genes that prevent fatty acid synthesis were activated.

This diet is particularly rich in seaweed, seafood, legumes, vegetables, fruits, and traditional Japanese fermented seasonings. In short, there are many kinds and it is worth recommending. At the same time, less sugar.

In subsequent experiments, the researchers also found that the mice that ate the 1975 meal lived longer, had better memory in old age, and had fewer diseases. (In fact, epidemiologist Zhang Shu and colleagues recently published research results that show that as we age, Japanese cuisine can make people healthier and more active in old age.)

The Tsuzuki team and collaborators found that this diet also has a positive impact on human health. In a 28-day trial of overweight people, the group who ate the 1975 meal lost more weight and had better cholesterol readings.

Other studies have also found that healthy weight people who ate the 1975 meal were in better shape than others at the end of the trial.

Du Zhuyi and colleagues observed the changes in gut microbes during the study and believed that people’s gut microbiota may be one of the factors affecting these results.

So, what is the secret of Japanese longevity?

Tsuzuki pointed out that if this version of Japanese cuisine is good for health, in addition to its special nutrients, it may also be related to the way the food is prepared.

Japanese meals usually consist of several small dishes with different flavors. Moreover, cooking methods often use steaming or slow stewing instead of frying.

At the same time, use a small amount of flavorful seasonings instead of excessive sugar and salt when seasoning.

In short, the benefits of Japanese cuisine may not be because of the quality of seaweed and soy sauce, but because of the emphasis on healthy cooking, moderate consumption of different kinds of rich foods, and emphasis on eating more vegetables and legumes.

In other words, this type of advice applies to anyone.

But modern Japanese society has also encountered its own problems when following this advice. The incidence of diabetes in Japan has increased in recent years, partly because of the aging population, but also because of the increasing obesity rate.

Perhaps, Japan’s “birthday country” days are also numbered.