Natto is a Japanese fermented soybean condiment that has traditionally been a breakfast staple. “Eat your natto” tumbles out of Japanese parents’ mouths with the same it’s-good-for-you tone as American parents might say, “Drink your milk” or “Eat your broccoli.” Most Americans have never heard of natto, despite the love affair in this country with sushi and Japanese food.
Soybeans are the richest source of protein of all the legumes. When we add the bacteria B. subtilis var. natto, it produces enzymes that digest these proteins into simpler forms of peptides or even simpler amino acids, which makes them easier for us to digest. As the bacteria digest the proteins, they release ammonia, making the natto kind of stinky. The bacteria also digest the carbohydrates, to a point where the sugars are at near zero after 18 hours of fermentation.
The health benefits of eating natto regularly are clear and impressive, and the depth of the research is strong and convincing (we will get deeper in post over the next few months). If there is a true superfood, it might just be natto.
Topping the list of soybeans’ vitamins is K, a fat-soluable vitamin that comes in two forms. You might remember something about leafy greens and vitamin K — that’s K1. It’s found in plant foods because plants require it for photosynthesis. So, eat your veggies and you get your K1, which helps our blood to clot. Vitamin K2, on the other hand, isn’t produced by plants but rather by bacteria, and it can be found in cheeses, sauerkraut, and fermented soybeans like miso and natto. Natto has by far the highest concentration — 15 times more than hard cheese, and over 200 times more than sauerkraut — which is good news for those of us looking to increase our bone density. K2 is thought to build bone health as well as heart health, among other things. Studies indicate that K2 decreases the incidence of bone fractures in women with postmenopausal osteoporosis. [[ Iwamoto 2006]]Vitamin K2 comes in many forms; menaquinone-7 (MK-7) is the form most easily used by the human body, and natto’s vitamin K2 is nearly all in this form. [[Yanagisawa 2005]]
Are you ready to eat some natto, here is an easy recipe. You can find natto frozen in most Asian stores, or from makers such as NY natto. Our new book out in June will show you how to make your own step by step.
Natto Caesar Salad
Yield: 2 - 4 servings
You’ll be surprised by how creamy this dressing is. For this easy salad, make the dressing in the bottom of the bowl, add crisp romaine lettuce leaves, toss, and top with croutons. We also use this dressing for other chopped greens, like kale, and it works quite well. It needs to be used immediately, so we just make what we need for one meal.
3 garlic cloves
1 healthy tablespoon natto (page 00)
1 ounce oil-packed anchovies, drained (optional)
{1/2} cup olive oil
2 tablespoons mayonnaise, preferably homemade (page 000)
2 tablespoons lemon juice
1 tablespoon apple cider vinegar
1 healthy teaspoon Dijon mustard
{1/4}–{1/2} teaspoon freshly ground black pepper
Salt
1 head romaine lettuce or other greens, torn into bite-size pieces
Croutons
1. Place the garlic, natto, and anchovies, if using, on a cutting board. Using a knife, mince them together, chopping back and forth across the pile until the mixture is mostly smooth. You don’t want large chunks.
2. Place the natto mixture in the bottom of the salad bowl. Add the olive oil, mayonnaise, lemon juice, cider vinegar, mustard, pepper, and salt to taste and whisk together. It will thicken quickly and take on a natto-y texture. Don’t be concerned.
3. Place the lettuce in the bowl and toss until the lettuce is evenly coated. Top with a generous helping of croutons and serve.
