How Strong are your Bones?

"...It wasn't raining when Noah built the ark."

According to the National Institutes of Health (NIH), ten million Americans (80-90% of them women) are known to suffer from osteoporosis. In addition, an estimated 18 million women with low bone mass have yet to be diagnosed or treated.

Even though osteoporotic fractures are more common in women than heart attack, stroke, and breast cancer combined, many physicians do not consider osteoporosis a leading diagnostic priority. A recent large study in New England noted that less than 10% of all clinicians, regardless of specialty ranked bone density as the first or second most helpful screening test (in relation to blood pressure, cholesterol, mammogram, thyroid, PSA and stool testing). GYNs were more likely to rank osteoporosis screening as a priority (50% of GYNs vs 13% of internists and 10% of family physicians).

In another recent study, only 20% of older women who sustained fractures were given a bone density evaluation by their health care practitioner.

What Is "...bone density"?

Bone is dynamic, always being built up, always breaking down. Bones have a central matrix or "cortex" that maintains their strength. New bone is always being made by cells called osteoblasts, and older bone broken down and metabolized by cells called osteoclasts. In with the new and out with the old! The idea is to build up enough new and not lose the old!

How to Build New Bone and Prevent Loss

The most important element in bone metabolism and whether or not you'll get osteoporosis is genetics. But, since there's no cosmic way I'm aware of to modify your genes, let's stick with what we know.

To build new bone you need 3 things: protein (from food); calcium and vitamin D (and maybe magnesium) from food or supplements; and exercise (to mobilize the calcium). Calcium requirements are approximately 1200 mg per day under age 60 and 1500 mg per day over 60/65. Vitamin D 800 I.U. per day and magnesium maybe 600 mg (although not absolutely necessary). Dietary sources of calcium include milk and yogurt (+/- 300-400 mg/cup), broccoli, collards, bok choy, kale, sardines, and tofu with calcium sulfate (200-300 mg/serving). "Older" (over 70/75) people should pay particular attention to protein, calcium and vitamin D intake.

Bone loss rates are very much up to genetics, but sex, age, and mineral supplementation play a large part. Women, who have an abrupt cessation of estrogen production at menopause, lose bone faster than men, who experience a much slower tapering of their testosterone levels as they age. Both estrogen and testosterone help prevent excessive bone loss.

Other compounds that may be utilized for bone loss prevention include the SERM (Selective Estrogen Receptive Modulator) raloxifen or Evista. "SERMs" are compounds that "look like" estrogen to the bone (and occupy estrogen receptors), while acting like an anti-estrogen in the breast.

A class of compounds called "bisphosphonates" (Fosamax, Actonel, Didronel) also help prevent bone loss and have no hormone-like actions.

Testosterone and DHEA may also be helpful in preventing loss.

The best way to treat osteoporosis is to prevent its occurrence! Once it has occurred, however, it is of paramount importance to stop it in its tracks and hopefully reverse the loss. If the situation is severe, a combination of two methods may be helpful. If it is quite severe and/or you've already sustained a fracture, a new daily injectable medication called Forteo (synthetic parathyroid hormone) is the very best to reverse loss. Needless to say it is extremely expensive.

Who is at Highest Risk for Osteoporosis?

Although anyone may develop bone density problems, Caucasians and Asians not ingesting a lot of soy are at increased risk, especially if they are slender. Smoking, excessive alcohol intake, sedentary lifestyle and, of course genetics (family members with osteoporosis) are risk factors.

Another significant risk factors are certain medications, the worst of which are steroids and some anti-convulsant medications. Individuals on long term corticosteroid therapy for rheumatoid arthritis, asthma, or other pulmonary conditions should take some form of protection.

Likewise, women who have (had) an eating disorder or very low BMI and have missed periods, or women who have taken Lupron or Provera over 6 months are at increased risk.

Diagnosis (who should have a bone density)?

Anyone who is at risk should have a bone density determination. This may be via a peripheral (heel) screen or central DEXA (Dual Energy X-ray Absorptiometry). A calcaneus (heel) screen gives an idea as to whether you are "OK" or potentially low. If you are low, you will need a central hip/spine DEXA to determine your exact loss.

All women should have a peripheral screen at menopause, as should high risk individuals at a younger age. Women at significantly increased risk (2 or more risk factors) should probably have a DEXA, as should all women over 65. Every 2 years is an appropriate interval to follow the results of therapy (and for women over 65), although occasionally a greater or lesser interval is appropriate. New urine test (Pyrilinks, CTX, NTX) are also helpful in ascertaining bone loss.

Remember what your mother said: "an ounce of prevention is worth a pound of cure."