Tokyo 1930
Secrets of Green Tea

Do you drink green tea for its health benefits? You can thank Japanese biochemist Michiyo Tsujimura (辻村みちよ, 1888–1969), Japan’s first female doctor of agriculture, seen here at her research institute in Tokyo in 1930 (Showa 5).

Tsujimura identified and isolated several components of green tea, including vitamin C and catechins. Her discoveries had such a large impact that it contributed to an increase in Japanese green tea exports to North America.

Tsujimura was born only 34 years after U.S. gunboats forced Japan to open its borders in 1854. By the time of her birth, Japan was enthusiastically embracing modern scientific methods and education.

As she grew up, the doors of Japan’s educational institutions were slowly opening to women, creating opportunities that previous generations of Japanese women had never had.

Tsujimura grabbed these opportunities with both hands. She studied biochemical science under biologist and cytologist Kono Yasui (保井コノ, 1880–1971), who in 1927 (Showa 2) became the first Japanese woman to receive a doctoral degree in science. Yasui inspired and fueled a burning passion for scientific research in Tsujimura.

On September 1, 1923 (Taishō 12), Tsujimori was conducting an experiment at Tokyo Imperial University when the powerful Great Kanto Earthquake hit and destroyed Tokyo, Yokohama and surroundings, killing over 100,000 people. She ran out of the building holding a highly valuable and accurate analytical balance.

Her laboratory destroyed, Tsujimura moved to the Riken Foundation, a scientific research institute founded in 1917 (Taishō 6) which survives to this day. Here she studied under Japanese scientist Umetaro Suzuki (鈴木梅太郎, 1874–1943), one of the world’s earliest modern vitamin researchers, who discovered vitamin B1. Suzuki asked Tsujimura to research vitamins in green tea.¹

In joint research with her colleague Masataro Miura (三浦政太郎), Tsujimura discovered that green tea contained high levels of vitamin C. Merely a year after surviving the devastating earthquake, they published On Vitamin C in Green Tea in the journal Bioscience, Biotechnology, and Biochemistry. The paper emphasized the properties of green tea that could prevent or cure scurvy. As these properties were completely absent in black tea, the publication lead to a massive increase in the export of green tea.

In 1929 (Showa 4), Tsujimura was the first person in the world to isolate and extract catechin. Recent research suggests that green tea’s catechins have potent antioxidant activity. They are potential therapeutical tools that can counterbalance neurodegenerative events associated with aging and related diseases.² They also have cancer preventive and therapeutic effects.³

Tsujimura extracted tannin in crystal form and determined its chemical structure in 1930 (Showa 5).

Based on this research, Tsujimura earned her doctorate in agriculture from Tokyo Imperial University in 1932 (Showa 7). At 43 years old, she was Japan’s first female doctor of agriculture.

More discoveries followed, leading to her being awarded the Japan Prize of Agricultural Science (日本農学賞, Nippon Nōgakushō) in 1957 (Showa 32). In 1968 (Showa 43), one year before her death, she was decorated by the Japanese emperor with the Order of the Precious Crown of the Fourth Class.⁴

Looking back on her career, she told her students, “my research work was full of difficulties but it was very enjoyable. Finding no regrets in my life was my supreme happiness.”⁵

Postscript: Google Doodle

Although her name may not be familiar to the general public, Tsujimura has not been forgotten by the scientific community. In 2021, Tsujimura’s 133rd birthday was celebrated with a Google Doodle.

Soon after Google published the Doodle, sites all over the world wrote about her. Many used this photo from my private collection. Although it is now all over the internet, very few took the trouble to credit or reimburse me for discovering, acquiring, researching, scanning and sharing it.

Kudos to Newsweek Japan who did attribute the image, and reimbursed me for my efforts in searching out images like this all over the world, and bringing them back to Japan to give them a loving home.

It takes a lot of time, effort and money to find, acquire, scan, restore, research, conserve and share these images. If you enjoy seeing this unique visual heritage of Japan, or reading the articles, please consider supporting Old Photos of Japan with a regular amount each month.

This helps me to continue this work, and share the photos and research with you.

Notes

¹ 山西貞、古川英、編集：舘かおる、小山直子（2003）辻村みちよ 資料目録。東京：お茶の水女子大学ジェンダー研究センター、１５。

² Andrade, José Paulo, Assunção, Marco (2015). Diet and Nutrition in Dementia and Cognitive Decline: Chapter 84 – Green Tea Effects on Age-Related Neurodegeneration: A Focus on Neuronal Plasticity. Academic Press, 915-924.

³ Islam Rady, Hadir Mohamed, Mohamad Rady, Imtiaz A. Siddiqui, Hasan Mukhtar (2018). Egyptian Journal of Basic and Applied Sciences
Volume 5, Issue 1, March 2018: Cancer preventive and therapeutic effects of EGCG, the major polyphenol in green tea. Taylor & Francis, 1-23.

⁴ 山西貞、古川英、編集：舘かおる、小山直子（2003）辻村みちよ 資料目録。東京：お茶の水女子大学ジェンダー研究センター、１７。

⁵ ibid, 9.

Published January 16, 2022
Updated January 16, 2022 8:57 PM

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