A research team led by Akiko Minamisato and Tetsuya Mizokami of the National Center for Global Health and Medicine in Japan has recently discovered that people who follow a "healthy Japanese dietary pattern," which includes frequent consumption of vegetables, soy products, fruits, and seaweed, show a significantly lower frequency of depressive symptoms.
The research team conducted a questionnaire survey in 2006 of 521 workers (aged 21 to 67) in Fukuoka Prefecture, inquiring about their dietary habits over the past month and any depressive symptoms they experienced. The researchers classified the participants' dietary habits into three patterns: "healthy Japanese diet," "animal-based diet rich in meat," and "Western-style diet with bread for breakfast," and further subdivided the adherence to each pattern into strong, medium, and weak.
The results found that individuals with a strong adherence to the healthy Japanese dietary pattern had a 44% lower frequency of depressive symptoms compared to those with a weak adherence. However, no significant association was found between the degree of adherence to the animal-based or Western-style breakfast patterns and the occurrence of depressive symptoms.
Tetsuya Mizokami pointed out that this result does not indicate a direct relationship between depressive symptoms and the intake of specific nutrients, but rather emphasizes the importance of the overall dietary pattern. He explained that people with depressive symptoms might not be eating properly, but a Japanese diet could play a role in preventing such symptoms.
Akiko Minamisato stated that since 1998, Japan's annual suicide rate has exceeded 30,000, and the number and frequency of people experiencing depressive symptoms have also been increasing. It is now necessary to re-evaluate the value of the Japanese diet.
This research has been published online in the European Journal of Clinical Nutrition.