4 Health Benefits of Miso in Your Diet

December 9, 2018

Miso is one of my favorite medicinal superfoods, and I prescribe it for most of my patients. The taste, versatility, and simplicity of this ancient Japanese culinary staple will always have a place in my diet. So, what is miso?

Fermenting soybeans with salt, a fungus known as koji (Aspergillus oryzae), and sometimes other ingredients like seaweed, rice, barley, rye, wheat, millet, or hemp seeds produces miso, a thick paste that can be mixed with a variety of foods, most notably to make a delicious soup. Longer fermentation times, from 120 days up to three years, lead to more complex flavors.

Consider these four reasons for adding miso to your dishes:

Supports digestion as a pre- and probiotic

To ferment miso, koji is first grown on steamed white rice and harvested before combining with cooked soybeans and other ingredients. The fungus produces digestive enzymes, including amylase and protease, that break down starches and proteins into simpler sugars and amino acids, making digestion easier for us.

Pediococcus acidilactici and Lactobacillus plantarum are two species of beneficial bacteria that also commonly grow in the miso during fermentation. P. acidilactici produces lactic acid that helps break down lactose, improve the absorption of nutrients, and prevent intestinal infection by harmful bacteria. L. plantarum produces lysine, an amino acid necessary for all the body’s protein and numerous biological processes, from metabolism, to calcium absorption, and even modifications to the human epigenome.

The dietary fiber content of miso also makes it an effective prebiotic, helping to feed our gut microbes. Make sure to buy unpasteurized miso from the refrigerated section and add miso at end of cooking to ensure its living probiotics remain beneficial.
Delivers minerals and vitamins

High in zinc, manganese, phosphorous, copper, iron, magnesium, and calcium – miso provides several minerals that many people are deficient in. Each is vital for proper functioning of many human biological processes, such as maintaining a strong immune system and healthy metabolism.

Miso is even a good source of Omega 3 fats, providing 3% of your minimum daily requirement per tablespoon. Good amounts of Vitamins K, B6, B2 (Riboflavin), B1 (Thiamine), and choline are found in miso, as well.⁽¹⁾
Combats radiation and carcinogens

On August 9th, 1945, physician Tatuichiro Akizuki was working in a hospital in Nagasaki, Japan, 1.4 km from the hypocenter of the second atomic bomb dropped near the end of World War II. Afterwards, he along with 20 other employees and 70 tuberculosis patients did not have any acute radiation disease, which Dr. Akizuki credited to their consuming cups of wakame miso soup daily.⁽²⁾

Research exploring the protective benefits of miso against radiation have shown that miso consumption before radiation exposure increases the survival and regrowth of glands in the small intestinal, which are necessary for nutrient absorption and immune function. Compared to shorter fermentation times, 180-day fermented miso showed the most benefit.⁽³⁾

Lactic acid bacteria such as the P. acidilactici found in miso can effectively bind heterocyclic amines, which are carcinogenic chemicals produced on meat and vegetables if charring occurs during cooking. So consuming miso along with other foods may help prevent damage to your body’s cells and reduce the risk of developing cancer from exposure to compounds like the heterocyclic amines in charred food.⁽⁴⁾
Provides a complete protein

Miso is a source of complete protein, containing all the essential amino acids for human health. Each tablespoon of miso provides about 2 grams protein, and a bowl of miso soup typically has about double that.

For an excellent miso soup recipe, see the first entry on the Soups page of my website and follow along as I make the soup in this video below.

In Japan, it is common to begin the day with a bowl of miso soup, to provide energy and resilience for the activities ahead. So don’t shy away from enjoying some umami flavor each morning.

Stay tuned for my upcoming blog where I will talk about ways to incorporate miso into your diet.