Summary of Key Points
Japanese fermented foods are not inherently associated with a "refined aesthetic" or "health benefits." Their origin can be traced back to the survival struggles of ancient lower-class communities, who faced dual challenges: harsh geographical conditions (high temperatures and humidity making food preservation difficult) and political restrictions (a thousand-year ban on meat consumption, leading to protein deficiencies). During the Meiji Restoration, these foods were seen as a symbol of backwardness and nearly disappeared. It was only through scientific modifications, militaristic propaganda, and post-war marketing that they were transformed into symbols of national pride and health remedies. However, the true value of fermentation lies in enhancing the nutritional content of food, not in curing diseases. These foods carry hidden risks, such as high salt levels and the presence of bioamines. Their popularity is also influenced by the East Asian cultural belief in the unity of medicine and diet.
1. Ancient Fermentation: A Survival Strategy, Not About Refined Taste
Why did ancient Japanese people practice fermentation? It wasn't out of leisure; it was a matter of survival:
- Geographical Constraints: Japan's hot and humid summers, coupled with the lack of refrigeration and sealing technology, meant that fish, meat, and beans would spoil quickly.
- Political Restrictions: In 675 AD, Emperor Tenmu issued a ban on meat consumption, leaving the population without access to protein-rich foods for over a thousand years. They had to rely on fish and soybeans, which were prone to decay. The solution was to use wild bacteria to ferment these foods, allowing them to last longer.
For example, "nazo sushi," the precursor to modern sushi, involved stuffing crucian carp with rice and salt and fermenting it for a year or two. The resulting sticky mixture, though unpleasant, served as a preservative for the fish. Natto (Japanese fermented soybeans) originated when soldiers during the Heian period wrapped cooked beans in straw and hung them on horses; the combination of horse sweat, salt, and bacteria turned the beans into a fibrous product that was considered "barbaric" food by the nobility.
2. The Meiji Restoration: Fermented Foods as a Symbol of Backwardness
With the Meiji Restoration in 1868, Japan sought to align itself with Western standards, and fermented foods became a source of embarrassment:
- Official Disapproval: Emperor Meiji broke the meat ban, and eating beef caused a national sensation. Enlightenment thinker Fukuzawa Yukichi argued that a meatless diet weakened the population, making it difficult to compete with the West. Doctors influenced by German medical practices condemned natto and pickled vegetables as causes of diseases like cholera and typhoid.
- Comparison with China: Although China also adopted Western ideas in the late Qing dynasty, traditional Chinese medicine protected the value of fermented foods like tofu and soy sauce, which were not seen as inferior.
3. The Comeback: Military Needs and Capital Marketing
Fermented foods made a comeback thanks to three key factors:
1. Scientific Advances: During the Sino-Japanese War, soldiers suffered from beriberi (a vitamin B1 deficiency). Scientists were tasked with isolating beneficial fermentation bacteria; in 1912, Dr. Hanaze Jun from Tokyo University isolated the natto bacterium and rebranded fermented foods as "scientific achievements."
2. Militaristic Promotion: During World War II, when meat was scarce, natto and other fermented foods became a staple for the civilian population. The government promoted them as symbols of national strength.
3. Health Marketing: With economic growth in the 1970s, the middle class sought health benefits. Companies exaggerated the health claims of fermented foods, such as the presence of "nattokinase" that could dissolve blood clots (although oral enzymes are ineffective in the stomach).
- Exaggerated Claims: These products were marketed with stories about "artisanal production" and "century-old fermentation processes," creating a sense of luxury.
4. The Truth About Fermentation
Fermented foods have some benefits, but they are not as miraculous as advertised:
- Positive Aspects: Fermentation breaks down substances in soybeans that hinder nutrient absorption, making proteins more accessible. Natto also produces vitamin K2 and enhances B vitamins, giving the food a fresher taste.
- Hidden Risks:
- High Salt Content: A bowl of miso soup contains about 2 grams of salt, exceeding the WHO's daily limit of 5 grams. High salt consumption in regions that consume more fermented foods is linked to higher rates of stomach cancer and stroke.
- Bioamines: Fermentation can produce bioamines that may cause headaches and skin irritation in some people.
- Live Bacteria: While some products claim to contain billions of live bacteria, most are killed by stomach acid, and any surviving bacteria are quickly eliminated by the gut flora.
5. The Cultural Background: The East Asian Philosophy of "Medicine and Diet"
Japanese reverence for fermented foods stems from a cultural belief in the unity of medicine and diet:
- Eastern Medicine: The idea that food should nourish the body aligns with the concept of "clearing the intestines and eliminating toxins."
- Ritualism: Processes like stirring natto 400 times are seen as ways to activate its "spiritual properties," reflecting a focus on maintaining intestinal balance.
- Cultural Spread: This belief is prevalent in countries with chopstick cultures (China, Korea, Vietnam, Taiwan), where there is a strong emphasis on the digestive system's role in health.
In summary, the story of Japanese fermented foods reflects a combination of historical necessity, commercial strategies, and cultural traditions. The concept of "medicine and diet being one" has deeply influenced Japanese food culture, as seen in practices like natto and miso production that originated from ancient times and continue to shape modern Japanese cuisine.
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