ABSTRACT
Soy and soy products, traditionally eaten in Asian countries, are being proved to contribute to the health of mankind worldwide, particularly of the Japanese, who are enjoying nearly the longest life expectancy in the world. The CARDIAC Study has confirmed that Okinawans living in Hawaii still eat a lot of soy products and traditional Okinawan vegetables rich in antioxidants, fish, and seaweed. The differences in soy and fish intakes were demonstrated in Japanese immigrants, particularly in Brazil, by measuring 24-h urinary isoflavone or taurine excretions as the biomarkers of the dietary intake of soy products or fish and measuring the percentage of n-3 fatty acids in plasma phospholipids as the marker of fish consumption. The lower coronary heart diseases mortality in the Japanese and Chinese can therefore be ascribed to the high consumption of soybean products. Isoflavone excretion in 24-h urine is a reliable biomarker of soybean intake, since the frequency of soy product intake is associated with the excretion.
