BIOLOGY & MEDICINE
INTERVIEW WITH DR. SADAO HATTORI
Using Low-dose Radiation
for Cancer Suppression and Vitalization
Dr. Hattori is the Vice President in charge of Nuclear Energy of Japan's Central Research Institute of the Electric Power Industry (CRIEPI). He directs Japan's research program on the effects of low-dose radiation, conducted at 14 universities. A 1959 graduate of Tokyo Institute of Technology with a master's degree in nuclear engineering, Hattori received his Ph.D. from the University of Tokyo with a thesis on the risk assessment of nuclear energy. He has been a guest professor at Tokyo Institute of Technology and at the Nagoya Institute of Technology, and he has held his present position at CRIEPI since 1989. Hattori was interviewed by managing editor Marjorie Mazel Hecht in April 1997, and published in 21st Century Science & Technology. Summer 1997, Vol. 10, No. 2.
Question: Japan now has a unique and wide-ranging program of research into the health effects of low-dose radiation. How did the program get started?
In 1984, I came across an amazing paper on hormesis by Dr. T.D. Luckey in the December 1982 issue of the journal Health Physics. I sent a copy of Luckey's paper to F. Cutler and J. Taylor, the president and vice president of the Electric Power Research Institute (EPRI) in December 1984, asking them how they could explain what Luckey reported. They then decided to evaluate Luckey's paper.
In August 1985, there was a conference in San Francisco, called the Oakland meeting the first radiation hormesis international conference. After this conference, EPRI answered my letter, saying that Luckey's paper was interesting and scientifically accurate but not the full story. EPRI decided to fund some research activities on this at the University of California at Los Angeles, UCLA, under Professor Mackinodan. EPRI asked him in 1986 to do some tests to confirm radiation hormesis.
Meanwhile, in Japan, we formed a group to study the hormesis papers cited by Luckey, checking the data with specialists. After a few years of study, we initiated our radiation research program in 1988. We formed a committee, including many university professors, and specialists in the medical and biological fields. We then decided to perform some animal tests, which began in 1989. This stimulated many people in the concerned fields in Japan. Many specialists were interested in this, and they asked me to do some research. Gradually, after being asked by many, many people, I was obliged to expand my activities, based on this interest. Our program expanded, so that now we work with 14 universities on medical activities.
Question: What are the dimensions of your budget for this research?
Well, I have to explain how Japanese universities work. The universities are mainly funded by the government, and medical research is funded by the Health Ministry. There is much active medical research ongoing, some privately funded. So, all I had to do is to add some small amount to the ongoing programs where researchers agreed to do some radiation hormesis research. For example, one professor in one university might be working with several people in a project already; so I would pay perhaps $10,000 or $20,000 for the hormesis research.
Question: Because the research institution was already supported.
Yes, completely. Salaries, the facilities, the equipment I didn't need to pay for that. So it was quite easy to work with the universities. However, our budget has become larger recently; it's now about $700,000 yearly.
Question: What are the main areas you are investigating?
There are three major areas. Number one is the immune system, immune stimulation to suppress cancer, work with the tumor suppression gene p53. This is an exciting field stimulated by Professor Sakamoto, who is doing cancer therapy in a hospital, and Professor Onishi, who is doing the p53 research. The second area is rejuvenation, or vitalization of the bodies of mammals by low-level radiation. For example, vitalization of the essential activities such as membrane permeability of brain cells; suppression of diabetes; SOD or super-oxide dismutase, which suppresses oxidation of cell tissues by free radicals, so we can keep ourselves young; and the important activity of sodium-postassium pumping through cell membranes, the in-and-out movements, which can be driven by Na+K+APTase (an enzyme essential for cell activities). This work is mainly done by Dr. Yamaoka of our institute. He is working with many professors of many universities now. And, additionally, Professor Yamada is interested in the modulation of psychological stress, mental stress how you can keep high tension down using low-level radiation. This also, we understand, comes under rejuvenation or vitalization. The third area is adaptive response. Now, the United Nations Scientific committee on the Effects of Atomic Radiation (UNSCEAR) admitted that low-level radiation stimulated DNA repair activity, and if the damage is too severe, apoptosis activities are stimulated. This is a very interesting field now in nuclear medicine.
Question: So, these are the three major areas of research at the 14 universities.
Yes, and there are some other universities now asking to join our research program.
Question: What are the most important results you have seen over the past decade?
Most important, I think, are Professor Sakamoto's amazing results for human cancer suppression, treating lymphoma patients, and also saving the lives of people with liver cancer. It was amazing. However, this radiation effect may be effective only with certain persons, depending on certain biological characteristics. The have found this by analyzing the immune system response of many patients.
I also think that Professor Yamaoka's results with rejuvenation are amazing. If you look at the many natural radon springs around the world, such as Bad Gastein in Austria, however, they are applying only a primitive state of radiation treatment. By doing some research and analyzing the optimum exposure, we could produce further excellent effects. We have to find the optimum exposure to revitalize people.
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Figure 1
SURVIVAL RATES OF NON-HODGKINS LYMPHOMA PATIENTS WITH AND WITHOUT TOTAL BODY IRRADIATION
Lymphoma patients who were given a total body irradiation of 10 centigray by X-ray, three times a week, in addition to the standard local high dose irradiation treatment, had a 90 percent 6-year survival rate. The control group, which received only the local high-dose tratment, had a 36 percent 6 year survival rate.Source: Dr. K. Sakamoto, Tohoku University

Low dose (0.25 gray) irradiation fostered an increase in SOD (superoxide dismutase) activities, which suppress oxidation of cell tissues by free radicals, in various rat organs. The effects of one irradiation continued for up to 8 to 12 weeks.
Source: Dr. K. Yamaoka, CRIEPI

PROTECTIVE EFFECT OF LOW-DOSE IRRADIATION FOR MICE
WHO THEN RECEIVE A HIGH-DOSE IRRADIATION
Mice irradiated with a low-dose (50 centigray) two weeks before a second, high-dose irradiation (7,4 gray), had a much better survival rates (top line) than the control group, which did not receive the low-dose irradiation.Source: Prof. Yonazawa, Osaka Prefecture University and Mr. Misonah; CRIEPI

Figure 5
LIFESPAN OF ATOMIC-BOMB SURVIVORS
Residents of Nagasaki who were not exposed to the atomic bomb radiation have higher death rates after age 55, than those who were exposed. The dotted line is the non-exposed population; the solid line is the exposed population.Source: Mine et al., 1981, « The Current Mortality Rates of A-Bomb Survivors in Nagasaki City, Japan Journal of Public Health, Vol. 28, pp. 337-342.