The Japanese superfoods you should be eating

The Japanese diet is often praised for promoting healthy eating and longevity. As Japan is home to some of the world’s longest-living people – with an estimated 92,139 centenarians living in the East Asian country – the diet certainly has plenty of merit.

Fresh ingredients and staples like rice, fermented and pickled vegetables, fish and meat play a major role in Japanese cuisine. A 2016 study published in the British Medical Journal (BMJ) found that people who adhered to Japanese dietary guidelines had a reduced risk of dying early from heart disease or stroke.

When you zoom in further into the Japanese diet, there are any number of foods that may be unfamiliar to many of us, but are nevertheless a regular part of this particular way of eating. Some of these may even be considered ‘superfoods’ - foods that are considered to be exceptionally nutritious.

In the UK, these lesser-known superfoods can be hard to find. However, seaweed varieties like nori, wakame and kombu, as well as fermented foods like miso and natto, can be found in some specialty stores, such as the largest Japanese food hall in Europe, Japan Centre.

The terms ‘kombu’, ‘natto’ and more might sound totally obscure, but dietitians reassure us that these foods have genuine benefits for our gut health and can contribute to a healthy diet.

Watch: How to Adopt Aspects of the Shoku Iku Japanese Diet Plan

Why is the Japanese diet good for you?

A traditional Japanese diet is especially praised because it prioritises fresh and unprocessed foods, high levels of oily fish and fermented foods, says registered dietitian Lucy Kerrison.

"Oily fish is high in omega-3s, particularly DHA and EPA, which are the types of omega-3s that exert the most benefit on human health," she explains to Yahoo UK.

"Fermented foods have been shown to improve gut health and some may also support blood sugar control and metabolic health.

"The Japanese diet is also high in isoflavins, [which can be found in foods like soy, tofu and miso]. A diet high in isoflavins can be beneficial for women entering menopause and there is some research to show this can reduce symptoms of the perimenopause, such as hot flushes. This is thought to be as their structure is similar to oestrogen and can mimic its effect in the body."

Additionally, the Japanese diet includes plenty of polyphenol-rich foods, adds Dr Emily Prpa, nutritionist and science manager at Yakult.

"Polyphenols are compounds that are found in lots of brightly-coloured plants such as fruits and vegetables. In fact, that’s what provides their colour.

"It’s also present in herbs, spices, nuts, soybeans, and green tea - which is often drunk daily by many Japanese people. Polyphenols have a symbiotic relationship with the gut.

"They can help the gut function well and act as a source of food for your gut microbes, similar to fibre, whilst the gut can help polyphenols to work effectively - polyphenols have anti-inflammatory effects. Our gut bugs help break down polyphenol into useful compounds which can then help with digestion."

3 Japanese superfoods to add to your diet

Amelia Trillo, marketing executive at Japan Centre, explains that superfoods can be found in many day-to-day foods, such as salmon, avocado and blueberries.

"In Japanese cuisine, there are many ingredients which are considered superfoods due to their high fibre content, probiotic properties and containing many vitamins and minerals."

Kombu, wakame, nori

These are different varieties of seaweed often used in different parts of Japanese cooking. Most people may be familiar with nori, which appears frequently in sushi dishes.

However, kombu is a thicker type of seaweed that is often sold dried or pickled in vinegar. It is one of the three main ingredients used in dashi, a soup stock that is widely used throughout Japanese cuisine.

Wakame, on the other hand, is a type of kelp that has a sweet flavour. It is usually used in soups, like miso soup, and salads.

Whichever seaweed you choose to try, you will likely benefit from consuming it regularly. Kerrison says: "Seaweed is rich in vitamins, minerals and antioxidants."

However, she warns: "Seaweed contains high levels of iodine, which should be avoided in some people such as those with thyroid issues or who are pregnant."

Natto

It’s no secret that fermented foods feature heavily in Japanese cuisine, with ingredients like miso becoming a staple pantry item in many British households. However, one fermented food that might take a bit more getting used to is natto.

Natto is a traditional food made from whole soybeans that have been fermented with Bacillus subtilis var. natto. It has distinct characteristics like the appearance of sticky strands that hold the soybeans together, and a strong smell and flavour, often compared to a pungent aged cheese.

Kerrison says that the isoflavins in natto "can support hormonal health". She adds that this food is also a prebiotic and "supports the growth of good bacteria in the lower gut". "Natto is also a rich source of vitamin K as well as numerous minerals."

Dr Prpa also points to a BMJ study that revealed a 10% decrease in the risk of fatal stroke or heart attack for individuals who consume fermented soy-based foods daily. "Natto contains fibre, probiotics and vitamin K2. This combination may explain why it has been suggested natto intake could have health advantages such as decreased incidence of certain illnesses and a lower risk of death."

Umeboshi

Umeboshi is a popular type of Japanese pickle, in this case, it is a pickled plum. It is usually very salty and sour, and are usually served as a side dish for rice or eaten on rice balls.

Trillo says: "Umeboshi is enjoyed in all sorts of dishes, you’ll commonly find it in bento lunch boxes, in onigiri rice balls, on ramen and even in alcohol and sweets. It’s high in citric acid content, which can help the body recover from fatigue and restore appetite."

Other types of popular Japanese pickles include pickled cucumber, radish and lotus roots. When you add these to your diet, Trillo says: "You’ll be adding a wider variety of healthy gut microbes, which help digest the fibre in your food, strengthen your immune system and protect you from pathogens."

Read more about gut health:

• Adding salt to food could raise stomach cancer risk by 40%, study says (Yahoo Life UK, 5-min read)

• Gut health expert Tim Spector reveals key to long-term intermittent fasting (Yahoo Life UK, 5-min read)

• A father's gut could affect overall health of his baby, study finds (Yahoo Life UK, 2-min read)