Original Article

European Journal of Clinical Nutrition (2006) 60, 129–135. doi:10.1038/sj.ejcn.1602277; published online 5 October 2005

Phyto-oestrogen intake in Scottish men: use of serum to validate a self-administered food-frequency questionnaire in older men

Guarantor: C. Heald.

Contributors: CH conducted the study and prepared the first and final draft of the manuscript, CB-S assisted with the methodology and analysis and contributed to the manuscript, MR created the isoflavone database as used in the study and contributed to the manuscript, MM carried out the gas chromatography-mass spectrometry analysis of the samples and contributed to the manuscript, FA assisted with the study design and methodology and contributed to the manuscript.

C L Heald1, C Bolton-Smith2, M R Ritchie3, M S Morton4 and F E Alexander1

  1. 1Public Health Sciences, University of Edinburgh, Medical School, Teviot Place, Edinburgh, UK
  2. 214 Six Mile Bottom Road, West Wratting, Cambridge, UK
  3. 3Bute Medical School, University of St Andrews, Fife, UK
  4. 4Department of Medical Biochemistry, University of Wales College of Medicine, Cardiff, UK

Correspondence: Dr CL Heald, Public Health Sciences, University of Edinburgh, Medical School, Teviot Place, Edinburgh, EH8 9AG, UK. E-mail: charlotte.heald@ed.ac.uk

Received 15 October 2004; Revised 22 July 2005; Accepted 2 August 2005; Published online 5 October 2005.

Top

Abstract

Objective:

 

To study dietary intake and serum concentrations of isoflavones in order to provide relative validation of isoflavone intake estimates from the Scottish Collaborative Group – Food-Frequency Questionnaire (SCG-FFQ).

Design:

 

Validation study.

Setting:

 

Southern Scotland.

Method:

 

Dietary intake of isoflavones was estimated using the semiquantitative SCG-FFQ and rank correlation and Kappa statistics were used for the relative validation of intakes against serum isoflavone concentrations in 203 male participants who were population controls in a case–control study of diet and prostate cancer.

Results:

 

The median intake of isoflavones (daidzein and genistein) was 1.0 mg/day (I-QR 0.6–1.8). The median serum concentration of genistein was 33.79 nmol/l (I-QR 14.12–64.93), nearly twice that of daidzein (18.00 nmol/l, I-QR 8.26–29.45). Equol was detected in 49% of subjects; in these subjects the median was 0.67 nmol/l (I-QR 0.34–1.51). Isoflavone intake was significantly correlated with serum concentrations of daidzein (rho=0.24, P=0.001), genistein (rho=0.26, P<0.001) and total isoflavonoids (sum of daidzein, genistein and equol) (rho=0.27, P<0.001). Whereas values for weighted Kappa ranged from 0.16 (P=0.002) for daidzein and equol combined to 0.22 (P<0.001) for genistein.

Conclusions:

 

These results demonstrate the suitability of the SCG-FFQ to rank usual isoflavone intakes in older Scottish men, a population observed to have low consumption of soy foods.

Keywords:

isoflavones, diet, validation study, daidzein, genistein, biomarker

Extra navigation

.

naturejobs

More science jobs
Post a job for free
ADVERTISEMENT