Significant Effects of Mild Endogenous Hormonal Changes in Humans: Considerations for Low-Dose Testing

The 2001 document reviews the health effects of small hormonal changes in humans and the implications for testing chemicals that affect hormonal activity. It notes the endocrine system's sensitivity to mild imbalances, which can cause significant health issues, including effects on puberty, menstrual cycles, aging, stress, nutrition, exercise, and chronic diseases. The paper discusses systemic effects of gonadal imbalance and borderline hormonal imbalances, such as subclinical thyroid disorders and glucose intolerance, and suggests that even low levels of hormonally active compounds can have biological effects. It calls for more sensitive testing methods for endocrine disruptors and considers the health consequences of mild hormonal imbalances beyond reproductive issues, including bone density, cardiovascular health, mood, and the risk of hormone-dependent cancers. The document also examines the challenges in setting medical thresholds for diagnosis and treatment, emphasizing the importance of individual susceptibility and environmental factors in health risk assessments.