Miso originated in China and was brought to Japan in the sixth century and then refined throughout the centuries. Now, it is considered an essential Japanese ingredient, in traditional and contemporary cooking.
Miso is made by inoculating cooked soybeans with a starter culture called koji. The koji culture has a mold in a base of rice, soybean or barley. The inoculated soybeans and any added grains are mashed with salt and water, then left to ferment. Fermentation, which often takes 12 months, produces a wealth of nutrients as well as a rich, intense flavor.
Studies have associated miso consumption with a reduced risk of gastric, breast, colon and liver cancers.
Miso is unusually rich in nutrients, due in part due to the fermentation process required to produce it. This process breaks down the complex and sometimes hard to digest oils, proteins and carbohydrates found in soybeans into forms more easy for the human body to digest.
Thus it’s no surprise to find that regular consumption of miso – as is common in Japan, with many residents eating one bowl of miso soup per day – has been found to reduce the risk of breast, colon, lung and prostate cancer, among other health conditions. Miso consumption even appears to offer some protection against the effects of radiation.
If you are trying to avoid soy-based miso, you can instead go for other kinds of miso that do not contain gluten or soy, such as chickpea miso or adzuki bean-based miso. There is a great miso sold by a company named South River that I found to be the best miso available, and they have options that are gluten and soy free.
Four years ago, the World Health Organization reported the Japanese, who consume large amounts of fermented soy foods like natto and miso along with green tea, ginger and ocean herbs, have the longest lifespan of any people in the world.