Osteoporosis is a disease that causes bones to weaken and become brittle. This causes bones to break easily. Osteoporosis is often referred to as "the silent disease" and can progress in the body without symptoms for decades. In many cases, drugs used to treat arthritis as we age, especially corticosteroids, can also weaken bone stock.
In women, the number of wrist fractures increases as they approach middle age and plateaus after age 65. This is most likely related to the rapid loss of bone (osteoporosis) in the years following menopause. Since men don't experience menopause, bone loss is less common and the incidence of wrist breaks remains fairly constant.
As a side note – perhaps the only benefit, or "lucky break", that might be attributed to a wrist break (particularly in a mature female) is that it may actually serve as an early warning sign of osteoporosis. A broken wrist can forecast an increased risk of additional fractures, particularly in the hip and spine, in the future.
Talk with your doctor about osteoporosis. Appropriate treatment could help reduce the risk of a future break as well as improve the quality of your life.