This book was a revelation for me. As someone who has been an activist in the breast cancer space for decades, and who wrote her dissertation on the subject, I've been stuck in the early 1990s premature findings from the Women's Health Initiative study in the US that suggested estrogen replacement therapy can cause breast cancer. Unbeknownst to me, there has been a tremendous amount of research proving that to be false AND that taking HRT (hormone replacement therapy) can help to prevent really critical aspects of female aging: Alzheimer's and bone density loss among others. For anyone who is perimenopausal or already in menopause, I strongly recommend you read this book to get a clearer picture on the role estrogen plays in our bodies as we age.