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Estrogenic activities in rodent estrogen-free diets
Paolo Ciana1, Andrea Brena, Paolo Sparaciari
1Department of Pharmacological Sciences, Center of Excellence on Neurodegenerative Diseases, University of Milan, Italy.
Endocrinology
|September 10, 2005
Summary
Commercial diets contain estrogenic compounds that activate estrogen receptors (ERs) in mammals, independent of diet metabolism. This challenges the notion of "estrogen-free" diets and raises questions about the necessity of dietary ER-active compounds for metabolism.
Area of Science:
- Endocrinology
- Molecular Biology
- Nutritional Science
Background:
- Standard bioassays often fail to detect estrogenic activity in diets.
- Estrogenic compounds are pervasive in nature and can activate estrogen receptors (ERs).
Purpose of the Study:
- To investigate the presence and impact of estrogenic compounds in commercial diets.
- To determine if dietary compounds can activate ERs in non-reproductive organs.
- To assess the role of dietary estrogenic compounds in mammalian metabolism.
Main Methods:
- Utilized ERE-Luc reporter mice to monitor ER activation.
- Employed molecular imaging to visualize ER activation in vivo.
- Administered synthetic diets and used orchiectomy and aromatase inhibitors to control variables.
Main Results:
- Commercial diets, even those considered estrogen-free, contain compounds that activate ERs.
- ER activation was observed in non-reproductive organs at levels comparable to 17beta-estradiol administration.
- This activation was independent of orchiectomy or aromatase inhibitor treatment, confirming dietary origin.
Conclusions:
- Commercial diets contain significant estrogenic activity not detected by standard bioassays.
- Dietary estrogenic compounds activate ERs in various organs, irrespective of the animal's hormonal status.
- The study questions the necessity of dietary ER-active compounds for normal mammalian metabolism.