Bone is living tissue, and that tissue responds to weight-bearing exercise, physiological conditions within the body, and dietary intake of minerals that contribute to bone growth and development.
Osteoporosis is a disease of the bones that can lead to painful and occasionally deadly fractures. Literally meaning “porous bones”, this condition results in reduced bone density that occurs gradually over a period of years.
The Causes of Osteoporosis
The main cause of osteoporosis is a decrease in estrogen levels in women (usually at the onset of menopause) and a decrease in testosterone levels in men, although the risk for men is significantly less than for women.
Calcium and phosphate are the two minerals that are most crucial for bone health. In older individuals, calcium and phosphate are reabsorbed back into the body from the bones if dietary intake is insufficient, and this leads to bone loss. Thus, brittle and fragile bones lead to an increased risk of fracture. And according to some sources, nearly 50% of all women over 50 years of age experience a fracture of the hip, wrist or spine at some point in their later lives.
Other potential causes of osteoporosis are kidney disease, eating disorders such as bulimia and anorexia nervosa, rheumatoid arthritis, confinement to bed, or taking corticosteroid drugs such as prednisone.
Confinement to bed and immobility contribute to bone loss and the development of osteoporosis, due to the fact that bone responds to physical exercise and weight bearing by becoming stronger and denser. Astronauts living in weightless conditions, individuals confined to bed, and those who are immobile are all unable to bear weight – thus, their bones begin to leach their calcium and phosphate into the bloodstream, resulting in decreased bone density.
Other Risk Factors
White women of European descent and Asian women are generally at greater risk for osteoporosis than others, as well as any individual with a family history of the disease. Other risk factors include:
• Prolonged cessation of menstruation
• Excessive intake of alcohol
• Hormone treatment for breast cancer or prostate cancer
• Cigarette smoking
• Abnormally low body weight
• Low dietary calcium intake
Osteoporosis and African American Women
Although a great deal of the literature on osteoporosis states that African American and Hispanic women are at a lower risk of the disease than White and Asian women, information on the website of the National Institutes of Health (http://www.niams.nih.gov/Health_Info/Bone/Osteoporosis/Background/default.asp) states very clearly that osteoporosis in African American women is both “underrecognized and undertreated.”
According to the NIH website, the risk of a hip fracture doubles every seven years as African American women age, and Black women are more likely to die from a hip fracture than their White peers.