Bones are in a constant state of building up and breaking down. Every year, 20% to 30% of an adult skeleton is “new”. When you are young, there is more bone building than there is bone breakdown. That’s why childhood is the time to build bone strength.
Until the age of 40, both phases are more or less equal, assuming you are not doing anything abusive to your bones. After 40, the breaking down begins to gradually exceed the building up. This happens to everyone, men and women alike, in varying degrees. Women, however, experience a more rapid loss of bone after menopause because of declining estrogen levels.
Everyone’s goal should be to slow down the natural aging of bones and not hasten it with poor lifestyle habits or “bone robbers”.
“A high calcium intake will not protect a person against bone loss caused by estrogen deficiency, physical inactivity, smoking, alcohol abuse and various medical disorders and treatments”, according to the National Osteoporosis Foundation.
When people undergo prolonged bed rest or immobilization, they lose bone. The same happens to astronauts who fly long missions in the weightlessness of outer space. Bones need the “stress” of physical activity to stay healthy.
In a 10-year Penn State University study on Caucasian girls from ages 12 to 22, exercise had a more significant impact in building bone than calcium intake.
It doesn’t pay to be a couch potato at any age. In a Tufts University study, postmenopausal women who were not on hormone replacement therapy did strength training for one year. They increased bone density by 1% while the sedentary control group lost 2% of their bone density.
Men usually lose bone at a slower rate than women because they start out with a higher bone mass and do not undergo menopause. But if they lead “senorito” lives, they can be at a higher risk of fractures than women as seen in a study of a rural Turkish village with the tradition of letting women do all the hard physical work.
The National Institutes of Health state that the longer you smoke and the more cigarettes you consume, the greater your risk of fracture in old age. Both men and women who smoke have significant bone loss when they get older.
Exactly why smoking affects bones in not clear. It could be due to smoking itself or because smokers tend to have other risk factors like alcohol abuse, less physical activity, and poor diets. Also women smokers tend to produce less estrogen and experience early menopause, both of which accelerate bone loss.
Excessive alcohol consumption is associated with low bone density and a higher risk of fractures, according to studies on alcoholics. Moderate alcohol intake, meanwhile, is associated with higher bone density in postmenopausal women. Researchers believe alcohol increases estrogen levels. Unfortunately, this also increases the risk of breast cancer.
Dieting may be good for your figure but it isn’t good for your bones. A Rutgers University study found that just six months of dieting decreased bone density by 3%. The researchers say that losing weight could cause a change in three hormones (parathyroid, estrogen, and cortisol) that affect the absorption and utilization of calcium.
However, the results of a Washington University study shows that although losing weight through diet alone causes bone loss, losing weight by exercising does not.
The diet only group ate 16% fewer calories for three months and 20% for nine months. The exercise only group did not reduce calories but increased energy expenditure through exercise by 16% for three months and 20% for nine months.
The diet only group lost more weight (18.1 pounds compared to 14.8 pounds) but they also lost more bone – an average of 2.2% at the lower spine, hip, and top of the thighbone. The exercise only group did not lose any bone.
So if you need to lose weight, don’t just diet. Make sure to include weight bearing, impact, and muscle strengthening exercises to protect your bones.
Severe restriction of calories (chronic crash dieting, anorexia nervosa, bulimia) has a very negative effect on bones because of the hormonal imbalances dieting produces.
So does a condition called “Female Athlete Triad”, in which athletes are not getting enough calories for the rigorous training they undergo and menstrual periods stop.
The sad part is that bone loss in young women can be irreversible. In a 1997 study, female athletes with eating disorders and menstrual abnormalities did not have normal bone mass density four years after their menses returned and in spite of undergoing estrogen hormone therapy and calcium supplementation.
Very thin women are at a greater risk of osteoporosis than women of normal weight. One scientist has even proposed there might be a good reason why menopausal women put on a little extra weight even if they exercise and watch their diet. Estrogen isn’t just made in the ovaries. It is can also be synthesized by fat tissue. Perhaps that small padding of fat is Nature’s way of protecting your bones.
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