A groundbreaking new study from the Japan Institute for Health Security has found that adults adhering to a traditional Japanese-style diet experience significantly lower rates of depressive symptoms. The research, the first of its kind conducted at this scale in Japan, could have important ramifications for public health and workplace mental wellness initiatives both in Thailand and worldwide.
The relevance of these findings is especially sharp for Thai readers. With depression rates steadily rising in Thailand and across Asia, understanding the role of diet in mental well-being may offer a practical and culturally adaptable path toward prevention. Modern Thai society, like Japan, is facing rapid urbanization, social isolation, and dietary shifts that impact both physical and mental health. As Thais increasingly adopt processed and Westernized eating habits, this new evidence spotlights the potential power of returning to traditional foodways.
The large-scale study surveyed 12,499 employees from five different corporations, with an overwhelming majority of male participants averaging 42.5 years of age. Researchers assessed dietary patterns, focusing on both the classic Japanese diet—characterized by rice, miso soup, fish, soy products, cooked vegetables, mushrooms, seaweed, and green tea—and a modified version incorporating fresh fruits and dairy. Participants reported their dietary habits and completed mental health screenings for depressive symptoms. Remarkably, 30.9% of respondents exhibited signs of depression; however, those who adhered most closely to a Japanese-style diet were significantly less likely to report such symptoms.
To mitigate potential confounders, the researchers attempted to isolate diet from other factors known to affect mental health, such as workplace stress, socioeconomic status, and pre-existing medical conditions. While causality cannot yet be definitively established, the robust association with dietary habits stands out. According to the institute’s press release, “Further research is required, but we hope the evidence shown among Japanese people can be used for public health measures in workplaces and areas concerning the prevention of depression” (Kyodo News).
Several foods in the Japanese diet are cited for their neuroprotective and mood-boosting properties. Seaweed and soy products, along with the folic acid in cooked vegetables, may aid in the regulation of neurotransmitters like serotonin and dopamine—chemicals vital to emotional stability. Fish, especially oily varieties rich in omega-3 fatty acids, have long been associated with reduced inflammation and improved brain health. Expert opinion from nutrition science supports these findings: “Omega-3 fatty acids are among the best studied nutrients for the management and prevention of depressive disorders,” notes a 2023 review in the Journal of Affective Disorders (ScienceDirect).
While research on the Japanese diet’s impact on depression is nascent, numerous studies have evaluated the Mediterranean diet—a similarly plant- and fish-rich regimen—which shows comparable benefits in reducing depressive symptoms (PubMed). The Japanese study’s novel contribution is its focus on its own cultural dietary traditions, which have previously received less scientific attention in the mental health domain.
The implications for Thailand are profound. Thai cuisine shares commonalities with Japanese food, such as high use of vegetables, rice, seafood, and fermented products. However, dietary trends among urban Thais are increasingly Westernized, with a surge in processed foods, sugary drinks, and fast-food meals. These trends parallel recent findings in Japan, where younger generations are drifting away from traditional meal patterns. Mental health professionals in Thailand have raised alarms about the links between diet, lifestyle, and the rising prevalence of depression and anxiety, especially among working-age adults (World Health Organization).
Beyond nutritional content, the Japanese-style diet emphasizes balance, variety, and mindful eating—cultural foundations embedded in the concept of washoku, recently granted UNESCO Intangible Cultural Heritage status (UNESCO). These principles resonate with Thai food culture, where communal eating and an abundance of vegetables and herbs have long been the norm.
The study also underscores the workplace dimension of mental health. With more Thais working long hours and dining alone or relying on ready-made meals, the findings advocate for corporate wellness programs that encourage healthy eating as a preventive mental health measure. Recent Thai government initiatives promoting workplace wellness might be strengthened by incorporating lessons from Japan’s approach (Ministry of Public Health, Thailand).
Yet experts urge caution in interpreting the new results. While the association between diet and lower depression risk is compelling, questions remain regarding causation and the role of socioeconomic status, cultural practices, and access to nutritious foods. As noted by the lead researchers, “Further research is necessary to build on these findings, especially to test their applicability in different cultural contexts and to determine how dietary interventions can be best implemented.”
Historically, Japanese foodways were shaped during the Edo period (1603–1868) by Buddhist dietary restrictions, abundant seafood, and rice cultivation, paralleling Thai culinary history’s emphasis on rice, river fish, and fermenting techniques. Both societies have experienced postwar modernization and the impact of globalization, which has transformed eating habits and meal structures—sometimes with adverse consequences for public health.
Looking ahead, the findings provide a pathway for future Thai policy and personal practice. Schools, companies, and community organizations can promote traditional food patterns, emphasizing fresh ingredients, variety, and the inclusion of seafood and fermented vegetables. Individual consumers can make small, meaningful changes: adding miso soup, increasing vegetable servings, choosing grilled fish, or replacing sugary drinks with green tea.
As more research emerges, public health authorities in Thailand may consider formal dietary guidelines that incorporate protective elements from both Japanese and Mediterranean models, tailored to local agricultural products and tastes. Promoting food literacy, supporting local farming and seafood industries, and incentivizing restaurants to offer healthy set menus could all contribute to a more resilient mental health landscape.
Practical recommendations for Thai readers include:
- Prioritize meals based on rice, vegetables, fish, soy products, and fermented foods, which align with both Thai and Japanese culinary traditions.
- Limit processed and sugary foods, which have been linked to higher depression risk in multiple studies.
- Adopt mindful eating habits and share meals with family or community when possible.
- Organizations and public health providers should consider integrating dietary education and traditional food promotion into mental health strategies.
For those struggling with depression, dietary changes are not a substitute for professional care, but can be a valuable part of a holistic approach to well-being. This landmark Japanese study highlights the potential of traditional diets not just to nourish the body, but to foster resilience in the mind—a lesson ripe for adaptation in Thailand and beyond.
Citations:
- Kyodo News: Japanese diet may help in fight against depression, study shows
- Japan Times: Washoku may prevent depression, Japan study says
- News-Medical.Net: Can a Japanese diet help with depression? Large study says yes
- Journal of Affective Disorders: Omega-3 and depressive disorders
- UNESCO: Washoku, traditional dietary cultures of the Japanese
- World Health Organization: Mental health in Asia
- Ministry of Public Health, Thailand: Health Promotion Initiatives