The constant barrage of news about the COVID-19 coronavirus is making many of us anxious and stressed. Besides the standard recommendations to wash our hands often for 20 seconds, one other way to keep ourselves healthy is to maintain a healthy, balanced diet. Besides the standard fruits and vegetables, there are some foods unique to Japan purported to be helpful for maintaining our health. Two in particular are definitely acquired tastes, but now may be a good a time as any to incorporate them into your diet.
Earlier this month there was a brief run on nattō (fermented soybeans) because a rumor circulated on social media that they helped to prevent people from contracting COVID-19. This was just speculation based on the fact that Ibaraki Prefecture, the nation’s top nattō producer, had no announced COVID-19 cases at that point.
While you should never believe too-good-to-be-true rumors, nattō does have a lot of health benefits. Slimy, sticky and pungent, this soybean product is very polarizing, even in Japan. It’s fermented, which helps keep our digestive systems in good order, and also promotes the growth of probiotics, which make it possible to absorb nutrients better. It’s also packed with dietary fiber and a long list of nutrients, especially protein and minerals like manganese and iron.
The usual way to eat nattō these days is to stir it several times until it’s really stringy and sticky, add soy sauce, mustard and other ingredients (usually included as flavor packets with the nattō), and eat it with plain rice. But up until the end of 19th century it was more common to eat nattō mixed into miso soup, which may have helped dissipate its pungent flavor.
These salt-preserved ume plums, also pronounced mume, are so sour and salty that it’s not unusual for someone who unknowingly pops one in their mouth to spit it out. But many people find their intense sour-saltiness quite addictive.
Traditionally, eating umeboshi has been believed to keep away most illnesses — there’s even a saying, “an umeboshi (rather than an apple) a day keeps the doctor away.” My grandmother used to give us one of her homemade umeboshi whenever we came back from playing outdoors during the summer, since it was believed that its sourness and saltiness helped combat natsubate (summertime fatigue).
Ume has the highest concentration of citric acid, which is purported to have antibiotic and anti-inflammatory health benefits, of any fruit, and umeboshi made with traditional methods usually have about 20 percent salt content. Umeboshi contain 7 grams of citric acid per 100 grams, more than twice the amount of lemon juice. Umeboshi also contain benzoic acid, thought to limit the proliferation of bacteria, which is why umeboshi are historically used in rice balls and bento boxes to keep rice fresh for longer.
Umeboshi are really not something you just munch on whole unless you’re truly addicted to them, and the high salt content taken straight isn’t too healthy. It is generally recommended to limit yourself to one per day. Think of them as a sour-salty seasoning with a rich, fruity flavor.
A lot of umeboshi sold these days are ajitsuke (flavored) umeboshi, and have some of the salt removed before being marinated in dashi stock or sweeteners like honey. (Traditional high-salt umeboshi keeps well without refrigeration, but de-salted umeboshi must be refrigerated.) I prefer using the plain, natural umeboshi and adding my own flavors.
Other healthy Japanese foods that are in season now include leafy green vegetables like komatsuna (mustard spinach), nanohana (rapeseed) and karashina (mustard greens); sansai (mountain vegetables) such as taranome (Aralia elata shoots), tsukushi (field horsetail) and ashitaba (angelica); and seaweed and other fermented foods.