Is Sake Good for Your Health?
Now and then during my time reporting on sake, I’ve come across studies on the health benefits of sake. It’s not a widely discussed topic, but one that you can expect to hear more of in the future.
In a talk I attended given at the Japan Society in New York in February 2019, Jun’ichi Maruyama, an associate professor of brewing microbiology at the University of Tokyo, referred to a paper in the journal Nature on the sequencing of the koji mold genome and the discovery of a vitamin synthesis mechanism that can result in the creation of Vitamins B1, B5 and B7.
The discovery opened new possibilities for koji-based products to be considered “functional foods.”
Today, the list of purportedly beneficial properties generated by koji includes helpful digestive enzymes, skin-enhancing amino acids, and something known as GABA (Gamma aminobutyric acid), which affects the parasympathetic nervous system and can produce a relaxing, calming effect. It has also been shown to reduce blood pressure.
Gekkeikan, Hakkaisan and Chiyomusubi breweries all offer GABA-enhanced amazakes and Hakkaisan sells100-milliliter cans of plum sake enhanced with 10 milligrams of GABA as well. Chiyomusubi’s GABA-enhanced amazake is made with a special rice developed by the farmers’ cooperative of western Tottori Prefecture, which the farmers say contains five-to-ten times the average level of GABA in sake rice. So Okasora, senior vice president of Chiyomusubi, says the amazake has been on the market in Japan since November 2020, and has been selling well, with sales projected to continue increasing. “I believe that drinking a little sake every day is good for customers’ health,” he says.
Gekkeikan, meanwhile, has also introduced fiber into its amazake, and notes on the above-linked research page, “We would like to connect the functionality created by fermentation to the benefits of beauty and health.”
GABA is a naturally occurring amino acid that works as a neurotransmitter in the brain. Our brains include proteins known as GABA receptors. When GABA amino acids—which are widely found in animal and plant foods—that we ingest latch onto them, beneficial effects are believed to ensue.
At the Japan Society lecture, professor Maruyama told me that as a result of current research into koji and vitamin synthesis, and as the mechanism is better understood, we’ll be seeing more functionally enhanced sakes in the future. But it’s important to note that the reason the above-named breweries are all making GABA-enhanced amazakes is that these are alcohol-free drinks. The lack of alcohol means that the rice content of these sakes, and hence their GABA content, can be elevated. GABA-rich alcoholic drinks are more problematic, since not only will they include less GABA, but the “functional” aspect of the drink will be offset by a hefty dose of alcohol.
Despite these limitations, Japan’s National Research Institute of Brewing is committing resources to studying the functional aspects sake fermentation, yeast and koji-kin (Aspergillus oryzae, the fungus that triggers the breakdown of rice starch into sugar during the brewing process).
On this page, NRIB makes it intentions plain, noting that the wine world has studies to show that the polyphenols in red wine have been shown to be heart-healthy, protecting moderate drinkers from coronary heart disease. The sake world would like its own studies proving what Japanese people have believed for centuries: that the substances produced by the magic of yeast and koji fermentation are beneficial to our health, too.
The research makes sense: Sake sales have fallen steadily since the mid-1970s, and alcohol consumption is dropping around the world and in Japan, despite the rise in Covid-19 stress drinking. Showing that sake, too can be grouped in the lucrative “functional” food and beverage category, and can even include alcohol-free sake products is a way of hedging bets. The functional foods market segment, which includes products such as probiotic yogurt shots and nutrition bars, was valued at USD $173 billion in 2019, and is expected to reach $309 billion by 2027.
The term “functional foods” actually originated in Japan in the 1980s, when the government applied the term to foods with proven health benefits. Included are foods rich in vitamins, minerals, probiotics, and fiber that have been shown to reduce inflammation and strengthen the immune system or heart health. In other words, healthy foods ranging from fruits and vegetables (berries, broccoli) whole grains (barley, buckwheat), spices and herbs (turmeric, cayenne pepper) to fortified dairy or grain products.
Folk Wisdom Preceded Science
But long before the term “functional foods” was adopted or the genome sequencing of koji-kin occurred, Japanese people intuitively, and through trial and error, knew fermented foods were good for you. Sake brewers and brew masters have noted for centuries that toji (master brewers) have the supplest, youngest-looking hands because of their constant immersion in koji rice and sake mash. When we traveled to Okayama Prefecture to visit Tadayoshi Toshimori, the man who revived one of the most popular sake rice varieties of modern sake, Omachi, he told us he was close to 80 years old, but looked much younger because of all of the junmai sake and sake lees-based products he has consumed over his lifetime.
Many breweries make skin care products based on koji mold-related products. Fukumitsuya Brewery in Ishikawa Prefecture, for example, has been researching the beneficial effects of koji for the past 25 years, and puts out several lines of skin care products based on fermented rice extract. The brewery notes that Kanazawa geisha used sake as a skin-care product in the form of sake baths.
Some Japanese prefer DIY fermented rice beauty treatments. My friend Junko, who like me, has been experimenting with using sake lees (sake kasu) and shio-koji (the traditional seasoning agent salted koji) in cooking and baking, tells me that one of her Japanese friends “just puts sake lees on her face and waits until it dries for a sake kasu facial!”
Parallel Efforts in Japan’s Tea Industry
Interestingly, the Japanese tea industry has also been conducting research into the functional benefits of tea, including the potential benefits of its GABA-content. Katsuya Shiratori, a soil scientist-turned-Japanese tea advocate, says that research on GABA and tea production in Japan has been going on since the late 1980s, conducted by the research institute of Japan’s Ministry of Agriculture, Forestry and Fisheries (MAFF). Research into the blood pressure-reducing effects of green tea has meanwhile largely been conducted by one of Japan’s top tea researchers, on behalf of black tea merchant Mitsui Norin. As with sake, this type of research is carried on by government researchers, academics, and private industry, sometimes working in concert with each other.
But Shiratori notes that he’s always careful when sharing information on the functional benefits of tea, making sure to include scientific references. “Information on functional benefits can be good, but occasionally come to bad,” he explains. He offers the Japanese caveat, 毒にも薬にもなる/doku nimo kusuri nimo naru, or “it can be both a poison and a medicine.” He explains, “If misinformation on health benefits is disseminated…that can result in damage to the tea industry.”
In the sake industry, researchers have identified 13 organic acids found in sake that can function as GABA-like substances. But they have yet to determine if and how these substances actually work on the human brain and nervous system, although empirically, we can all attest to the relaxing, and mood-enhancing effects of moderate sake consumption,
Shiratori and I share the hope that the functional benefits of Japanese sake and tea, as they are scientifically proven over time, will boost both of these traditional industries.
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