Japanese Diet Linked to Lower Depression Risk

Traditional eating habits may boost mental well-being, study suggests.

Adopting dietary patterns rooted in Japanese food culture could lead to fewer depressive symptoms, new research indicates. A large study has revealed that closely following a traditional Japanese diet might significantly reduce the likelihood of experiencing depression.

The Washoku Diet and Mental Health

Researchers examining approximately 12,500 working adults discovered that individuals adhering most closely to the washoku diet reported fewer depression symptoms. This traditional Japanese eating style emphasizes white rice, miso soup, fish, mushrooms, soy-based foods, seaweed, and green tea. In contrast, a more Western-style diet—typically rich in processed meats, refined grains, sugary snacks, and fried foods—was associated with higher reports of depression.

Those who followed a more modern, health-conscious version of the diet, which added fruits, raw vegetables, and dairy while cutting back on salty foods, experienced an even greater benefit. According to the study, the *more* someone’s diet followed these Japanese eating habits, the *less* likely they were to experience depressive symptoms.

Compared to those with the lowest adherence, people with the highest adherence to the traditional diet were 17% less likely to report depression. For the modern version of the diet, the risk was reduced by 20%.

Expert Insights

The findings remained consistent even after considering factors such as age, sex, and job stress. However, the benefits seemed less pronounced in individuals working very long hours, suggesting that high stress levels could diminish the positive impacts of a healthy diet.

Depression is a growing public health concern worldwide, and diet is increasingly recognised as a modifiable factor that may influence mental health. We found it encouraging that our results supported the hypothesis: individuals whose diets more closely adhere to dietary patterns rooted in Japanese food culture tend to report fewer depressive symptoms said lead researcher Haruka Miyake, of the Japan Institute for Health Security.

Although further research is required to establish a causal relationship between adherence to the Japanese diet and depression prevention, these findings highlight the promise of promoting traditional dietary practices as part of broader public health strategies aimed at improving mental health. added Miyake.

Feel-Good Foods to Incorporate

Foods rich in folate, a nutrient that supports the production of feel-good neurotransmitters like serotonin and dopamine, are common in traditional Japanese cuisine. These include seaweed, spinach, and other green, leafy vegetables. Edamame (young soybeans) and soy-based products like *natto* (fermented soybeans), soy sauce, tofu, and miso (fermented soybean paste) are also excellent folate sources. Additionally, these fermented foods nourish beneficial gut microbes, supporting both physical and mental health.

The Power of Vegetables and Green Tea

The traditional Japanese diet emphasizes colorful vegetables packed with beneficial compounds, including antioxidants that can help alleviate brain stress. Antioxidants protect against oxidative stress, which, when occurring in the brain, has been linked to inflammation, neuron damage, and mood disorders such as depression and anxiety.

Green tea is another key component that may bolster mental health. It contains catechins, potent plant compounds that safeguard the brain, along with L-theanine, an amino acid known to stimulate calming neurotransmitters like GABA, serotonin, and dopamine.

For an even higher concentration of brain-supporting compounds, consider matcha, a powdered form of green tea cultivated differently.

The Savory Secret: Umami

Umami, the fifth taste often described as savoriness, might also contribute to a sense of calm. According to the research paper, Umami not only enhances taste but may also promote relaxation by reducing heart rate and stimulating parasympathetic nervous activity. Together with the nutrient-dense composition of Japanese cuisine, the profound role of umami may contribute to its potential to prevent depressive symptoms.

This idea was supported by a randomized, placebo-controlled trial published in the journal *Foods* in 2021. In the *washoku* diet, umami originates from foods like miso, soy sauce, seaweed, and mushrooms. Other umami-rich foods include aged parmesan, anchovies, sun-dried tomatoes, egg yolk, chicken skin, slow-cooked beef, fish sauce, kimchi, and stocks or broths, particularly those made with meat or mushrooms.

The Benefits of Fish

Fatty fish are abundant in omega-3 fatty acids, which help reduce brain inflammation and encourage the production of mood-regulating neurotransmitters like serotonin. Fish also delivers high-quality protein, B vitamins (especially B12), iodine, and selenium, all crucial for healthy brain function and emotional equilibrium.

According to the National Institutes of Health, about 6.7% of U.S. adults experienced depression in 2020 (NIH 2020). Regular fish consumption has been associated with lower rates of depression and cognitive decline.

Avoiding Ultra-Processed Foods

The traditional *washoku* diet notably excludes ultra-processed foods (UPFs). Packaged snacks, ready meals, sugary cereals, and mass-produced baked goods are absent. Mounting research suggests that high UPF consumption is linked to an elevated risk of mood disorders like depression and anxiety. Focusing on home-cooked meals made from whole and minimally processed ingredients is a proactive step toward supporting brain and body health.