Interview with Professor Norihisa Kato
 
While alcohol is often associated with its various negative effects, it has also been recognized throughout history as the best of all medicines. In 2013, Professor Norihisa Kato demonstrated definitive evidence for the health benefits of small-amount alcohol consumption through animal studies. Today, his findings about the effects of alcohol are attracting a great deal of attention.
 
 Demonstrating the “J-curve effect” of alcohol through animal studies, for the first time in the history
 
      In 2013, Professor Kato released his world’s first findings under the title “Demonstration of the J-curve Effects of Alcohol through Animal Studies.”
    “A British researcher proposed in 1981 that a small amount of alcohol intake reduces mortality, while a high amount of alcohol elevates mortality (now called ’J-curve effect of alcohol’). Subsequently, this particular effect of alcohol was confirmed by many epidemiological studies. However, no animal studies had been conducted to demonstrate the J-curve effect of alcohol consumption. In fact, few studies on small-amount alcohol intake had been conducted in the 30 years or so since the release of the British report,” says Professor Kato.
    He learned about these facts from a casual conversation with a staff member of the National Research Institute of Brewing, whose office is located next to his laboratory. The conversation inspired Professor Kato to resume his studies on the effect of small-amount alcohol intake on human health, a subject that had long interested him.
 
    Numerous studies have been conducted on the health hazards of alcohol. Intake of water with over 30% of alcohol content exhibits acute toxicity in animal experiments. Various studies are being conducted even today concerning the mechanism of alcohol’s toxicity and the effects of alcohol on the metabolization of nutrients.
    “Since I was young, I have always been interested in the effect of small-amount alcoholic intake. So when I heard that there had been very few experimental studies concerning this subject, I decided to do research using experimental animals,” says Professor Kato.
    He launched a series of animal experiments, using mice and rats, to demonstrate the effect of small-amount alcohol intake, known as “J-curve” (previously called “U-curve” in 1981).
 
 
 
 The idea of giving water with alcohol content of 1% led to an unprecedented accomplishment
 
  Following are the details of his experiment:
    First, he gave senescence-accelerated model mice free access to one of three kinds of drinks: water containing 1% ethanol, water containing 2% ethanol and plain water, and kept the mice for 22 weeks. As a result, the aging speed of the mice given water with 1% ethanol was found to be slower than in those given plain water and water with 2% ethanol.
    Professor Kato explains, “There are various strains of senescence-accelerated mice. First, we used SAMP1, which develops regular symptoms of aging. Next, we used SAMP8, a strain that shows severe symptoms associated with aging of the brain, such as learning and memory disorders, and found that 1% alcoholic content had the effect of reducing brain senescence as well.”
 
 
    Furthermore, Professor Kato conducted a similar experiment on rats fed a high-fat diet, in which he observed improved liver function in a group of mice that were given water with 1% ethanol when compared with plain water and water with 2% ethanol.
    When these findings were announced, they became big news--both in Japan and abroad.
    “The idea of using 1% ethanol was quite new; that, I think, led our efforts to success,” says Professor Kato. In terms of human alcohol intake, 1% ethanol is equivalent to a 250-500 ml can of beer, which coincides with the “moderate alcohol intake per day” indicated by many epidemiological studies.
    “Our findings fundamentally changed alcohol-related studies. It was a complete innovation, marking a revolution of one research area and the emergence of an entirely new field. What contributed most to this development was a demonstration by animal studies,” comments Professor Kato.
    In the years to come, Professor Kato plans to study in further detail the mechanisms of the effects of alcohol and how alcohol works against cancer, dementia, diabetes and other diseases.
 
 
Meeting people from different fields of specialization prompted him to pursue his long-cherished dream of studying alcohol effects; support from those around him keeps him going
 

      Asked about his future career goals, Professor Kato answers that he wants to “conduct research that excites me.” “I believe all researchers share the aspiration of doing out-of-the-box research that transcends disciplines— the kind of research that allows us to think freely is exciting, and eventually moves us enormously. I myself have been dreaming of doing that kind of research.”
    Because of intense competition among researchers, continuing research is also a mentally exhausting process. Away from such hectic, day-to-day struggle, researchers tend to find “something,” the kind of encounter that directed Professor Kato himself to the recent research.
    “In my case, too, it really came out of the blue. It is great to engage in research activities that are fun, have direct relevance to society, and make everyone happy. And if we can contribute to society or our local communities with our findings, we will be happy and students will feel excited; that will have tremendous educational effects. I would like to continue looking for and engaging in that kind of research activities in the years to come.”
    It may not be an easy task for most researchers to realize their dreams while pursuing their lifetime research interests. “Meeting the right people is the key,” says Professor Kato. Having met the right people and made his dream come true, he would like to see the same thing happen  for his students, who will lead the future of science.
 
Norihisa Kato

Professor, Laboratory of Molecular Nutrition

January 1, 1981 – March 31, 2001: Associate Professor, Graduate School of Biosphere Science, Hiroshima University
April 1, 2001 – Present: Professor, Graduate School of Biosphere Science, Hiroshima University

Retired on March, 2017