Final answer:
Decreased estrogen levels contribute to middle-aged women's accelerated loss of bone density, especially around the time of menopause when estrogen production significantly diminishes, affecting bone health and increasing the risk of osteoporosis.
Step-by-step explanation:
The factor that contributes to middle-aged women's accelerated loss of bone density compared to that of men is decreased estrogen levels. This loss is particularly prominent around the age of 50, which is the approximate age at which women go through menopause. During menopause, the ovaries reduce in size and stop producing estrogen, a hormone that is critical for promoting osteoblastic activity and the formation of bone matrix. Without sufficient estrogen, there is an inadequate formation of new bone and an increase in bone resorption, leading to conditions such as osteoporosis. It is important to note that genetic factors, poor diet, lack of exercise, smoking, and alcohol consumption are also involved in bone resorption and overall bone health.