Urinary excretion of lignans and isoflavonoid phytoestrogens in Japanese men and women consuming a traditional Japanese diet

Am J Clin Nutr. 1991 Dec;54(6):1093-100. doi: 10.1093/ajcn/54.6.1093.


Epidemiologic studies revealed low mortality in hormone-dependent cancer in Japanese women and men consuming a traditional diet. We previously found that certain diphenolic food components, lignans and isoflavonoids, which are converted to biologically active hormone-like substances by intestinal microflora, may be cancer-protective agents. Therefore, we studied urinary excretion of these compounds (enterolactone, enterodiol, daidzein, equol, and O-desmethylangolensin) in 10 women and 9 men in a rural village south of Kyoto, Japan. The subjects consumed a typical low-fat diet with much rice and soy products, fish, and vegetables. An isotope-dilution gas chromatographic-mass spectrometric method was used for the assays. The urinary excretion of lignans was low but that of the isoflavonoids was very high. The excretion of isoflavonoids correlated with soybean-product intake. The low mortality in breast and prostate cancer of Japanese women and men, respectively, may be due to the high intake of soybean products.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Diet*
  • Estrogens / urine*
  • Estrogens, Non-Steroidal*
  • Female
  • Humans
  • Isoflavones / urine*
  • Japan
  • Lignans
  • Lignin / analysis*
  • Male
  • Middle Aged
  • Phytoestrogens
  • Plant Preparations
  • Urine / chemistry


  • Estrogens
  • Estrogens, Non-Steroidal
  • Isoflavones
  • Lignans
  • Phytoestrogens
  • Plant Preparations
  • Lignin