What is Natto: Benefits and Nutrition
You may not have heard about it yet, but natto is the next big thing to come to your kitchen. Hugely popular in Japan, natto is a fermented food made out of whole soybeans and is packed with immune, heart and gut-friendly nutrients. Natto has a unique consistency with a distinct taste and smell and with the growing popularity of fermented foods, it is definitely worth checking out. We take a look at what makes Japanese natto so good for you and how it could give your health and wellbeing a boost.
What is Natto?
Natto is a distinctly flavored traditional Japanese food made from fermented soybeans and is most commonly eaten as a breakfast dish. It can be said that natto is not for the faint-hearted, thanks to its strong, almost pungent odor and distinct nutty, earthy flavor which can take a little getting used to. The look of natto can also be a little challenging, characterized by a sticky, almost slimy texture. But looks can be deceptive, as this simple dish is actually a health-boosting powerhouse.
With over 7.5 billion packets of natto are thought to be consumed in Japan each year, the Japanese typically eat their natto beans topped with soy sauce or mustard and wrapped in rice or seaweed. You can even get sugar-coated natto and natto ice-cream.
What is Natto Made of?
Natto is a relatively new food to the Western menu and although an acquired taste, is starting to grow in popularity, thanks in part to the awareness of the health benefits of fermented ‘superfoods’. Natto can be found in most Asian supermarkets and is made by fermenting cooked soybeans. A member of the legume family – along with beans, peas and lentils – soybeans are a high-protein vegetable and are a staple of the Japanese diet. Fermented, and their health benefits go right up the scale!
Natto is made by soaking the soybeans in fresh water overnight and then steaming them in a pressure cooker for around an hour. A ‘natto starter’ – which contains natto bacteria or Bacillus subtilis – is then sprinkled over the steamed beans before being left to ferment for 24 hours. The resulting mix is cooled and aged for around a week to allow the unique character and flavor of the natto to develop. It is now ready to serve and eat.
The key to natto’s nutritional super-powers is in the fermentation, which creates the ideal conditions for probiotics – or gut-friendly bacteria – to develop and thrive. But natto is super nutritious in many other ways and contains a host of the nutrient good stuff that is essential for health. Natto is relatively low-calorie and low fat and is a whole carbohydrate that also packs in the fiber. Its vitamin and mineral rollcall is also pretty impressive and top of the list is its high vitamin K (K1 and K2) content, which has a host of health boosting benefits, including bones, digestive and heart health. And with natto one of the few plant-based sources of vit K, you also get vitamin C and B, alongside iron, copper, magnesium, calcium, potassium, zinc and selenium to complete the list. Not bad for a little fermented bean!
So, now we know its nutritional value, we can ask the question, ‘what is natto good for?’ And the short answer is – quite a lot! Here are just some of the main health benefits of this fermented bean superhero:
- Improves digestion
We all need the right types of gut bacteria to keep our tums happy and our digestive systems healthy but the stresses and strains of modern life – not to mention poor diets and processed food – can enable the bad bacteria to thrive. But getting enough probiotics – the good live bacteria – in your diet can help to rebalance and improve a stressed digestion.
The fermented nature of natto means that they are full of probiotics which will help to boost your gut’s natural flora. As well as reducing gas, constipation and bloating, there are also many conditions which can be helped by these probiotics, including inflammatory bowel disease, Crohn’s disease and ulcerative colitis. Natto is so high in probiotics that it is estimated that just one gram of the fermented bean contains almost as much as you would find in a whole serving of many other probiotic-rich foods.
- Boost bone health
Rich in several key nutrients, natto can also help to boost the health of your bones. Top of the list is calcium – of which a 100g portion of natto can provide 22% of the daily recommended amount – and vitamin K2. As one of the few plant-based sources of vitamin K2, this nutrient helps by activating bone-building proteins which help your bones absorb and retain their main mineral and building block, calcium. K2 can also help to slow ager-related loss of bone density and can help to reduce some osteoporosis-related fractures. There have also been studies which indicate that natto and its K2 load can help to boost bone mineral density in post-menopausal women.
- Enhances the immune system
As well as helping your digestive system to run smoothly, the probiotics in natto can also help to strengthen your immune system and reduce your risk to infection. It is although thought that a probiotic-rich diet which includes fermented foods such as natto can also help to reduce the need for antibiotics when recovering from an infection. A probiotic rich diet also reduces the production of harmful bacteria and could also support in the production of your body’s natural antibodies.
Natto is also loaded with a host of additional vitamins and minerals – specifically vitamin C, iron, zinc, selenium and copper – which are essential for a healthy immune system.
- Promotes heart health
Natto hits a positive beat when it comes to supporting the health of your heart. Both the fiber and the high levels of probiotics it contains can help to reduce cholesterol levels while the vitamin K2 helps to prevent calcium deposits building up in your heart’s arteries, reducing the risk of heart disease.
The fermentation process in natto also produces an enzyme called nattokinase, which can help to improve circulation, dissolve blood clots as well as help to prevent them forming in the first place. And it seems that when it comes to nattokinase, the stringier your portion of natto the better! Research has also suggested that natto may help to lower blood pressure, thanks to its ability to deactivate a blood pressure raising enzyme called ACE, or angiotensin converting enzyme.
- May cut the risk of certain cancers
Another reason to tuck into a bowl of natto is that it may help to lower the risk of developing some cancers. Eaten as part of a healthy, balanced diet, a portion of natto can help to protect against gastrointestinal, prostate, liver and breast cancer, thanks to the powerful combination of soy isoflavones and vitamin K2. Present in high levels thanks to the fermented nature of natto, soy isoflavones can also help to reduce the risk of stomach cancer.
- Good for brain health
Natto could also be a good source of ‘brain food’. Studies have shown the potential for the fermented soybeans to have a neuroprotective effect thanks to the high-quality probiotics natto contains. With gut health directly linked to cognitive functioning, natto can help to boost your brain and protect against cognitive decline. And, thanks to the heart and blood health properties of this simple fermented bean, a healthy cardiovascular system also contributes to the healthy functioning of your grey matter.
And finally, natto also contains vitamin K1 which adds to the dish’s blood-thinning properties, as well as the enzymes pyrazine and nattokinase. With these all working together, natto can also help to reduce the risk of the chronic condition, fibromyalgia as well as macular degeneration.
Are There any Side Effects to Natto?
With a packed list of nutrients and probiotics, natto is understandably being seen as one of the latest superfoods to add to your diet and is safe for most people. However, it does contain vitamin K1, which has blood-thinning properties. If you take blood-thinning medication, it is advisable to speak to your physician first before adding natto to your diet.
The nattokinase in natto could potentially lower blood pressure so if low blood pressure is an issue speak to your doctor as it may be best to avoid the dish. It is also recommended to stop eating natto two weeks before scheduled surgery.
Soybeans can also interfere with the functioning of the thyroid gland, especially if you already have an issue with an under or over performing thyroid so again, seek medical advice. But for healthy individuals, natto is a good food to eat.
How to Serve
There is no denying that natto can be an acquired taste, but for its high nutritional value alone, it is worth the effort to develop a liking for it.
It can have quite a distinct smell – it has been likened to cheesy socks – so some aficionados suggest starting with a small portion and build up from there. Or you can add it to other dishes and season well. Traditionally served in Japan as a breakfast, mixed with rice and delicious pickled vegetables or an Asian salad, natto is also tasty added to a miso to create a strongly flavored and nutritious soup. The secret is to mix natto in dishes which have a variety of flavor and seasoning that complement and enhance the unique natto taste! Or you could look for dried natto and sprinkle on Asian-style salads or stir-fries for a unique and healthy boost of this amazing Japanese superfood.