Saburi: Foods have three major functions, that can be chiefly categorized as nutritional function, taste function, and physiological function which activates the living body. The activating functions on the body include maintaining homeostasis and adjusting the nervous systems and hormones in order to maintain balance within the body. In other words, foods can have the effect of increasing natural healing power and enhancing the immune system.

Recently, importance has been attached to issues relevant to nutrition and the immune system. To take an example, when a person became sick, medicines play a role as "auxiliary treatment factors." On the other hand, the patient has, above all, to make an effort in using his own immune system to the maximum extent. So it is important to have proper nutrient management and to activate various metabolic pathways in his daily life so as to enhance a biophylactic function.

----What kinds of foods enhance the immune system? Please let us have the names of such foods.

Saburi: Many sorts of foods that can augment the immune system are known. It is claimed that Chlorella would help to enhance the immune system. In addition, it is possible to list many other foods, including fungi; algae, including a variety of brown algae, sea grape, laver on sea rocks; fermented foods made with with beer yeast, and those made from milk, such as yoghurt and fermented soybeans, called natto; molluscs, including abalone and scallop; vegetables including yams, carrots, beans and garlic; fruit such as kumquat, jujube and pine nut; green tea; and vegetable oil.

----In the U.S., Japanese food with cereals included as the core of the diet is highly valued, since such dietary habit is closely connected with enhancement of the immune system.

Saburi: Traditional Japanese foods such as cereals, algae and soybeans promote the growth of beneficial bacteria in the intestinal tract, giving the body a resistant power. People have to take such food every day bearing this idea in mind. But looking at such food from the viewpoint of enhancing the immune system, most of the substances included in natural foods that activate immunity are polysaccharides, components with little nutritional value. Their molecular sizes are so large that only a fraction is absorbed, even if a lot of such foods are consumed. If one takes foods in order to enhance the immune system, it is necessary to process them so that the ratio of absorption of the effective elements from the food into the blood is higher. As examples of immune enhancing foods for which function has been increased by means of biological and chemical processing, we can list arabinoxylan containing dietary fibers, garlic extract, sesame, extract of Korean ginseng, lactic acid bacteria and Vitamin C.

----Please let us have your views on how to distinguish and define the roles of pharmaceutical products and foods.

Saburi:Since the 19th century, chemists have extracted effective ingredients from plants used for medical treatment, and these have come to be used as drugs. They succeeded in extracting morphine for the first time aslong ago as 1807. Later, antibiotics such as penicillin produced by microbes, were progressively developed. Drugs have a role as "a symptomatic therapy" to alleviate infection and various diseases. But it is dietary therapy, designed around nutrient elements of foods, that is effective for illnesses like life-style related diseases, such as diabetes and hypertension, which have been increasing recectly due to the defective situation in the condition of nutrients. Diseases develop when the power to resist germs becomes weak, and antibiotics help by killing the germs. However, this is an auxiliary measure in recovery. It is essential to increase natural healing power, which a patient himself possess originally. In the case of conditions such as cancer and life-style related illness, for which therapies that can fundamentally cure the disease have not been established, it would be a key to prevent such illness through placing emphasis on daily nutritional management in order to augment the immune system.

----In the U.S., it appears that a trend is emerging of reviewing empirical treatment methods using Chinese herbal medicine and herbs, treating illness not only with pharmaceutical products as has been practised so far. Do you think Japan would follow suit? Please tell us how you view it.

Saburi: It would be very likely that Japanese medicine would move in a similar direction. I believe that Japan would also move with the big flow rising in America. The U.S. is seeking alternative medicines, because medical expenses have become too high where conventional Occidental medicine is continually performed. They are reviewing Ayulveda medicine of India, Japanese and Chinese medicine and herbal medicines in Europe, all of which use grass roots and tree barks. Among such empirical medicines, a new path for treatment is now being sought. Actually, at the National Institutes of Health, a significant budget is allocated in order to carry out the study on a large scale.

Furthermore, such movement by the US government is reflected in the market. With the enactment of the Dietary Supplements Health and Education Act of 1994 (DSHEA), labeling of vitamins and herbs has been regulated and deregulation of where they are sold has been achieved, as a result of which ordinary consumers can also enjoy the benefits of alternative medicine. Now, herbal products are readily available in supermarkets. Gingko leaves have become popular because their action for improving dementia has been noticed. A variety of vitamins and minerals can also be purchased easily.

----Intensifying the immune system by nutrient components of foods or immunotherapy has attracted much attention. What place do you think this notion will have in future medical treatment?

Saburi: The immune system has a protective function in which leukocytes try to eliminate germs attempting to invade our bodies. Theoretically, it would be possible to expect immunotherapy to advance and become intensified in the future. However, there is still a way to go in order to get to such a situation in reality. Not only foods, but also psychological factors substantially influence enhancement of the immune system. When immunotherapy is performed on a cancer patient with a positive attitude that it will work, it would be more likely to have a positive effect on the progress of the disease.