Why is the Japanese diet so healthy?

The Japanese have long been revered and studied for their long life expectancy, which is higher than almost anywhere else in the world. So why is the Japanese diet so healthy, and what do they eat?

What are the benefits of the traditional Japanese diet?

The traditional Japanese diet is largely fresh and unprocessed, with very little refined foods or sugar. 

A recent study by the British Medical Journal found that those who stuck to closer to the Japanese dietary guidelines – a diet high in grains and vegetables, with moderate amounts of animal products and soy but minimal dairy and fruit – had a reduced risk of dying early and from heart disease or stroke. As their diet is traditionally high in soy and fish this may also play a significant role in this reduced risk of cardiovascular disease. The Japanese also have the lowest rates of obesity amongst men and women as well as long life expectancy. 

Okinawa, in southernmost Japan, has the highest number of centenarians in the world as well as the lowest risk of age-related diseases (for example diabetes, cancer, arthritis and Alzheimer’s). This has partly been attributed to their traditional Japanese diet, which is low in calories and saturated fat yet high in nutrients, especially phytonutrients such as antioxidants and flavonoids, found in different coloured vegetables. This also includes phytoestrogens, or plant-based oestrogens, that may help protect against hormone-dependent cancers, such as breast cancer.

What is the traditional Japanese diet?

The Japanese diet isn’t that dissimilar to a traditional Chinese diet, with rice, cooked and pickled vegetables, fish and meat being staple choices. However, because Japan is actually a group of islands (all 6,582 of them), its residents consume a lot more fish compared to other Asian countries. They also eat raw fish in sushi and sahimi, plus a lot of pickled, fermented and smoked foods.

Soy beans, usually in the form of tofu or fresh edamame, are another key part of the Japanese diet, along with other beans such as aduki. Increasingly, fermented foods are being shown to support a healthy digestive system. Fermented soy bean products such as miso and natto are staples of the Japanese diet. Natto is traditionally consumed at breakfast and has a probiotic action that has been shown to help reduce IBS and may help blood clotting.

The Japanese also consume a wide variety of vegetables, both land and sea vegetables such as seaweed, which is packed full of health-boosting minerals, and may help to reduce blood pressure. Fruit is often consumed with breakfast or as a dessert, especially Fuji apples, tangerines and persimmons.

Alongside their diet, the Japanese are big fans of green tea and in particular matcha tea, which is fast gaining popularity in the UK. Matcha, a stone-ground powdered green tea, is most valued for its high antioxidant compounds known as catechins, which have been linked to fighting cancer, viruses and heart disease.

Which healthy eating behaviours are part of traditional Japanese culture?

The Japanese tend to have a healthy attitude to food and eating. They have a traditional saying, “hara hachi bu”, which means to eat until you are 80% full, and they start teaching it to their children from a young age.

The way the Japanese serve their food is also key. Rather than having one large plate, they often eat from a small bowl and several different dishes, usually a bowl of rice, a bowl of miso, some fish or meat and then two or three vegetables dishes, often served communally and eaten in rotation. The Japanese are also strong believers of ‘flexible restraint’ when it comes to treats and snacks, enjoying them from time to time but in smaller portions.

This blog was written for BBC Good Food