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Wholemeal rye bread as a source of phytoestrogens. K. LIUKKONEN (1), W. Mazur (2), K. Juntunen
(3), H. Mykkänen (3), H. Adlercreutz (2), and K. Poutanen (1). (1) VTT Biotechnology; (2) University of
Helsinki, Department of Clinical Chemistry, and Folkhälsan Research Center; (3) University of Kuopio,
Department of Clinical Nutrition.
Rye is a good source of plant lignans, such as matairesinol (MAT) and
secolariciresinol (SECO). The lignans have been shown to locate mainly in the bran, and to be converted to
the mammalian lignans enterolactone (ENL) and enterodiol (END) during colon fermentation. In humans
higher enterolactone levels have been shown to be associated with a lower risk of cardiovascular disease
and hormone-related cancers. Formation of ENL from wholemeal rye products was studied in in
vitro fermentation using human fecal inoculum. In addition, in a cross-over trial it was shown that rye
bread as part of the usual diet increased serum and urine ENL concentrations in healthy volunteers, as
compared to white wheat bread. The mean serum ENL concentrations were 25.6 ± 4.7 and 39.7 ± 6.5
nmol/l at the end of the rye bread period and 12.5 ± 1.6 and 14.8 ± 1.9 nmol/l at the end of wheat bread
period for men and women, respectively. Correspondingly, the daily urinary ENL excretion increased
significantly during the rye bread period. The levels of ENL both in vivo and in vitro were
higher than expected based on levels of MAT and SECO, indicating the presence of also other precursors.
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