Ancient Japanese Traditions of Soy Milk and Health

Soy milk’s popularity in Japan reflects a history that extends well beyond its role as an alternative to dairy milk. Sure, in Western countries many people replace cow’s milk with soy milk because soy milk is lactose-free, high in protein, and lower in cholesterol and saturated fat than dairy milk. But Japanese people have consumed both soy and dairy milk for centuries, and early medical writings discuss the benefits attributed to each.  

Japan’s first medical text, Formulas from the Heart of Medicine (Ishinpō), completed in 984, outlines the health benefits of both milks. However, historically, Japanese soy milk was much more widely consumed than dairy milk, so it has a broader history of positive cultural associations. No wonder the Japanese celebrate Soy Milk Day on October 12.

When Fujiwara no Michinaga (966-1028), one of the most powerful political figures in Japanese history, became ill in 1016, his doctor prescribed soy milk. Michinaga dominated politics by marrying his daughters and granddaughters to emperors. He may even have inspired the lead character in the first novel, Murasaki Shikibu’s Tale of Genji, and he was bold enough to compose a poem in which he compared himself to the moon looking down on everyone. So, it is extremely significant that his doctor prescribed him soy milk. Imagine what would happen to the doctor if Michinaga died!

Michinaga also received dairy milk when he was ill, so the ancient Japanese thought of soy milk as comparable to dairy milk. However, dairy products never caught on in premodern Japan due to a lack of rangeland for cattle. Japan became a land of soy milk and tofu, not cow’s milk and cheese. So, soy foods became deeply ingrained in Japanese culture. According to local lore in Tottori prefecture, if you eat tofu on December 8, you clean your mouth of all the lies you’ve told in the last year. Cheese can’t do that!

Japanese folk sayings capture the beneficial properties of soy. “Consume soybeans and be healthy” and “consume soybeans and get organized” are two sayings that play on the fact that the word for soybeans (mame) is a homonym for the word meaning fit and hardworking. These expressions reflect soy’s longstanding association with health and well-being in Japanese culture. Today, soybeans and soy milk are widely recognized sources of complete plant protein.

Soy is Japan’s most popular traditional health food, so it’s no wonder that in 2008 the Japan Soymilk Association established Soy Milk Day every October 12. Today, you can explore that tradition for yourself by enjoying Japanese soy milk on its own, adding it to your daily coffee or matcha for a boost of protein, or using it as a base for soups and desserts. Soy Milk Day offers a fitting occasion to discover Japanese soy milk’s mild flavor, smooth texture and versatility. Happy Soy Milk Day!

Celebrate Soy Milk Day with Japanese soy milk recipes here or learn more about Japanese soy milk here.

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