Do menopausal women need estrogen replacement to avoid osteoporosis?

This paper considers the hypothesis that modern gynecological practices relating to sex-steroid hormones reflect modern sedentary lifeways, along with pharmaceutical commercial pressures, to produce a widespread medical perception that all postmenopausal women need estrogen replacement therapy to avoid osteoporosis (bone fracture risk resulting from low bone density). Like the concept of menopause itself, the concept of universal menopausal osteopenia (low bone density) is a modern medical construction. Numerous clinical trials have demonstrated that estrogen replacement therapies (ERT) help women to retain bone mass in ageing, but several trials have also shown that ERT is primarily effective in sedentary women who do not exercise, Recent studies of ancient human bones suggest that bone-mass in women was higher in the pre-agricultural ancestral past due to greater physical activity demands and greater nutrient density than are common in modern corporeal lifeways. From an evolutionary perspective, the metabolic nature of bone as a tissue that can be increased or reabsorbed in response not only to sex-steroid hormone levels but also to dietary mineral and protein status, vitamin D, and mechanical loading appears adapted to an environment that was abundant in nutritional micronutrients, sunlight exposure and regular, demanding physical activity.