Assessment of the estrogenicity of the diet of a healthy female Spanish population based on its isoflavone content

Abstract

Phytoestrogens are natural components of plants consumed by humans. The hormonal activity of these substances has long been known. Various in vitro tests have demonstrated the agonistic or antagonistic estrogenic activity of some phytoestrogens. The objective of this study was to estimate the supply of isoflavones in the diet of a healthy adult female population and to assess its estrogenic effect. The diet was assessed by questionnaire and the estrogenicity of the estimated isoflavone content was tested by E-screen, finding a mean total estrogenic capacity of 0.129 × 10⁻¹⁰ eq.E₂ (12.9 pmol day^–1), corresponding to a daily isoflavone intake of 265.8 μg day^–1. This study offers a preliminary insight into the phytoestrogen content of the diet of a healthy active population of Spanish women. The effects of this additional hormonal burden are highly controversial, and this approach to estimating dietary phytoestrogen intake of specific populations may help to elucidate its implications for human health.

Keywords:

• estrogenicity
• diet
• isoflavone
• phytoestrogens
• healthy Spanish women
• exposure

Acknowledgements

The authors thank Richard Davies for editorial assistance. This work was supported by postdoctoral grant from University of Granada, by grant from the Spanish Ministry of Education (FPU Program) and Manuel de Oya Program (‘Cerveza y Salud’). Spanish Ministry of Health (INMA-G03/176), Andalusian Regional Government (AGR255 ‘Nutrition, Diet and Risk Assessment’) and European Union Commission (QLK4-1999-01422 and QLK4-CT-2002-00603).