On December 13, 2010, the 7th Annual Natto Health Food Seminar was held in Hamamatsu-cho, Tokyo, at the WTC Conference Center (World Trade Center Building, 3rd Floor).
The seminar’s theme was “how natto can contribute to a healthy mind and body,” and the objective of the seminar was for participants to gain further understanding of natto through the latest research on food nutritional science, food culture, and general macrobiotic food research.

Bacillus natto
Professor Nishihori, of Shikoku College, Human Health Division, Dietary Nutrition, presented his results on “natto’s polyamine concentrations – how to measure polyamine content.” Professor Nishihori reports that there are three types of polyamines involved in cell growth, with spermidine and spermine having the greatest anti-aging effects. Many different types of beans contain these two elements, especially if they are dried, but when these beans are made into baked beans, tofu, or miso, the polyamine content is greatly reduced. However, even when natto is preserved, the content of these two polyamines is not affected, therefore making natto a highly polyamine-concentrated product. One pack (50g) of natto contains 20% of a Japanese individual’s intake of spermidine and spermine, making natto a favorable source of polyamines.
Lastly, Assistant Professor Soda, of Saitama Medical Center Jichi Medical University spoke on the additional benefits of natto’s polyamines. According to Assistant Professor Soda, the molecular weight of the component in the human body that can be absorbed from the intestines and that digests and absorbs favorable elements is 1,000. Because spermidine and spermine, the polyamines contained in natto, have a molecular weight of 200, they are extremely easy to absorb. It has been shown that these polyamines are able to inhibit LFA-1, an inciting factor for inflammation, which can result in thrombosis.
Based upon an analysis of data from the WHO’s epidemiology survey and research on polyamine content in foods, Assistant Professor Soda recommends a Mediterranean diet, which includes olive oil, fruit, cheese, yoghurt, and seafood. Additionally, he explained that eating, on average, one pack (40~50g) of natto a day may prevent lifestyle-related diseases and the polyamines in natto may prevent diseases like arterial sclerosis.