Korean J Urol.  2006 Jul;47(7):773-778. 10.4111/kju.2006.47.7.773.

Effects of Dietary Habits on the Serum Isoflavones Levels

• Lee YS
• Lee SC
• Kim WJ

• KMID: 2294321
• DOI: http://doi.org/10.4111/kju.2006.47.7.773

Abstract

PURPOSE: Recent studies have suggested that isoflavones have an inverse correlation with the risk of prostate cancer. In addition, the serum isoflavones levels are thought to be decided not only by the level of intake of isoflavones, but also by the metabolic processes or the genetic abilities required for ingestion of isoflavones. So, we conducted this study to determine the effects of dietary habits on the serum isoflavones levels.
MATERIALS AND METHODS
One hundred age- and community-matched healthy men between the ages of 10 and 59 years were interviewed using a food frequency questionnaire that was developed and validated for Korean populations. The individuals' dietary habits during the previous one-year period and the foods they ingested during the previous one-week period before blood sampling were assessed. The serum concentrations of isoflavones were analyzed by the reversed-phase high performance liquid chromatography-multiple reaction ion monitoring-mass spectrometry method (HPLC-MS), (SRL Co. Tokyo, Japan).
RESULTS
The genistein and daidzein levels were significantly correlated with age (p=0.026 and p=0.016, respectively), but the equol level was not (p=0.091). The foods associated with the genistein level were unmilled rice, beans, garlic and etc. The foods significantly related to the daidzein level were unmilled rice, garlic and etc. Of the foods ingested during the previous one-week period, fermented soybean soup, garlic, strawberries and mung-bean pancakes were associated with the equol level.
CONCLUSIONS
The genistein and daidzein levels were associated with usual dietary habits, but the equol level was related to the short-period food consumption. Changes in dietary habit might induce significant changes in the genistein and daidzein levels.

Keyword

Daidzein; Dietary habit; Equol; Genistein; Isoflavones

MeSH Terms

Eating
Equol
Fabaceae
Food Habits*
Fragaria
Garlic
Genistein
Humans
Isoflavones*
Male
Metabolism
Prostatic Neoplasms
Surveys and Questionnaires
Soybeans
Spectrum Analysis
Equol
Genistein
Isoflavones

Figure

• 

  Fig. 1 Isoflavones' concentrations according to the age groups. The genistein and daidzein levels are significantly correlated with age (p=0.026 and p=0.016), but the equol level is not (p=0.091).

• 

  Fig. 2 Isoflavones concentrations in the two groups (10-39 vs 40-59 years). The isoflavones concentrations are significantly higher in the age ≥40 group than that in the age <40 group (genistein; p=0.009, daidzein; p=0.028, equol; p=0.037).

• 

  Fig. 3 Number of equol producers and equol non-producers (n=100). *: equol>0.167ng/ml, †: equol≤0.167ng/ml.

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