Osteoporosis, meaning porous bones, is the gradual loss of bone density. A silent process which may begin during a woman’s thirties, bone loss accelerates after menopause because of the decrease of the bone-retaining hormone estrogen. Women are eight times more at risk for developing osteoporosis than men because of:
Smaller bone structure and bone mass
Lower calcium intake
Decreased estrogen levels at menopause
Fewer opportunities to participate in physical activity throughout their life span and
Longer life expectancy
Twenty-five percent of post-menopausal women have osteoporosis and it does not show up on conventional x-ray until approximately 30% of the bone mass has been lost.
Peak bone mass occurs when our bones are at their strongest. Women of all races reach their peak bone mass between the ages of 20 and 24. Men keep building bone until about age 30.
Men are larger than women on average, and have a higher bone density.
Around age 40, both men and women begin to lose some of the bone in their skeletons. But in the next 10 years, women lose more bone leading up to menopause, because of changes in their estrogen levels. The hormone estrogen plays a key role in bone formation. After menopause (around age 51), women start to lose bone at an increased rate. A woman can lose 2 to 5 percent of her bone density each year during the 5 to 10 years of and following menopause.
The facts of women and osteoporosis are startling.
One woman in ten over the age of 65 has a collapsed vertebra
Osteoporosis accounts for on million hip, wrist, and spine fractures annually in U.S. citizens over age 45
50% of osteoporosis victims who fracture a hip never walk again
25% of women who fracture a hip die within a year
There are three main components in osteoporosis prevention: diet (calcium), physical activity or exercise, and estrogen. A daily calcium intake of at least 1000 mg. is needed if you are premenopausal, and 1500 mg. if you have gone through menopause (surgical or natural). This is because calcium is a vital component for any muscular activity.
The calcium available for muscular use comes from the bloodstream which comes from the foods we eat. If there is not enough calcium in the blood, it is drawn from the bones, leaving them weaker. Maintaining regular exercise that stresses large muscle groups in both the upper and lower body is also recommended in the prevention of osteoporosis. Activities should be both weight bearing and involve muscle contraction. Walking-jogging, tennis, bicycling and weight lifting are all good.
The activity should be done for at least 20 minutes several times per week. Estrogen can also play a role in the prevention of osteoporosis because it maintains calcium within the bones. Estrogen Replacement Therapy (ERT) is most effective in preventing bone loss if it is taken during the first 5-10 years following menopause (or loss of ovarian function). Women taking ERT should be followed closely by their physician.