July 2011 Issue

Treating Low Bone Mass — Three-Pronged Approach Focuses on Diet, Exercise, and Medication
By Densie Webb, PhD, RD
Today’s Dietitian
Vol. 13 No. 7 P. 12

Thirty-eight-year-old Gwyneth Paltrow is best recognized for her acting and singing careers, but she became known for her bones last year when she joined the ranks of the 34 million women diagnosed with osteopenia, a condition in which bone mass is lower than normal but not low enough to be classified as osteoporosis.

According to the National Institutes of Health, everyone begins losing bone after about the age of 30, the point at which bone mass peaks. For women, that bone loss accelerates after menopause. Paltrow’s loss, however, is more dramatic than most women her age.

Rather than being a disease in itself, osteopenia is considered a possible risk marker for osteoporosis and debilitating bone fractures. However, according to Lora Giangregorio, PhD, an assistant professor of kinesiology at the University of Waterloo in Ontario, Canada, the focus is now shifting away from using the term “osteopenia” as a diagnosis or as a cutoff point for prescribing medications. Rather, recommendations for bone health are made for anyone with less-than-optimal bone mass.

Diagnosis
Experts point out that low bone mass is not the only factor that determines fracture risk. While many women with low bone mass may have a greater risk of fractures, other women with the same bone mass may have a very low risk. Moreover, a diagnosis of low bone mass is not a clear predictor of osteoporosis. A risk profile tool called FRAX, developed by the World Health Organization, helps predict an individual’s risk of bone fracture over the next 10 years and takes into consideration several risk factors, such as age, race, smoking, diet, activity, medications, and age of menopause. The test is available at www.shef.ac.uk/FRAX.

Low bone mass has no symptoms. It is usually diagnosed with a bone mineral density test known as dual-energy x-ray absorptiometry, which can identify bone loss of as little as 2% in one year. Earlier this year, the U.S. Preventive Services Task Force issued new recommendations for bone mass screening.1 The agency recommended screening for all women older than 65 and for younger women who have a risk profile similar to that of a 65-year-old woman. The report avoided the use of the term osteopenia and instead referred only to low bone density revealed through screening. No recommendation was made for men because of a lack of evidence for screening’s effectiveness. However, the National Osteoporosis Foundation recommends screening for all men aged 70 and older.

Treatment
Whether it’s dubbed osteopenia, low bone mass, or low bone density, treatment is three pronged: diet, exercise, and medication. While customized changes in diet and increases in exercise are recommended for virtually everyone, regardless of age or degree of bone loss, the debate over whether to recommend medication is contentious.

Diet
The National Osteoporosis Foundation and the Institute of Medicine make the following dietary recommendations to prevent bone loss (Note that these recommendations apply to everyone.):

• Get enough calcium. The Recommended Dietary Allowance (RDA) for adults younger than 51 is 1,000 mg/day. For adults aged 51 and older, the RDA is 1,000 to 1,200 mg/day. People need to take a supplement if their dietary calcium level is inadequate.2 No specific recommendations have been made for low bone mass.

• Get ample vitamin D. The RDA for adults is 600 IU/day. This recommendation assumes minimal sun exposure. If dietary intake is low, a supplement is recommended. No specific recommendations are made for low bone mass.

• Limit intake of salt, caffeine, and soft drinks, as they can weaken bones when consumed in excess.

• Avoid consuming too much alcohol. Drinking more than two or three alcoholic drinks per day can harm bones.

Physical Activity
While exercise is routinely recommended for bone health, research findings as to the effect of regular exercise on bone have been inconsistent, depending on the bone site examined, the age of the study group, the degree and type of bone loss, and the intensity and frequency of the activity involved. The findings are further complicated when weight loss occurs as a result of an increase in physical activity since weight loss could have a negative effect on bone in women who are overweight or obese.3

However, according to Mary Jane Detroyer, MS, RD, CDN, a New York-based dietitian and exercise physiologist, “To build bone, you have to participate in weight-bearing exercise. Research clearly supports that.”

Weight-bearing exercises such as walking, hiking, and dancing are all good choices for the lower body, and adding exercise with light weights or elastic bands or straps can help the bones in the upper body. Less traditional forms of exercise, such as yoga, tai chi, and Pilates, may not only help increase bone density but also significantly improve balance by increasing core strength. Research has shown that better balance and improved gait translate into fewer fall-related fractures, regardless of the degree of bone loss.4

Detroyer, who regularly counsels patients on how to improve their diet and incorporate more physical activity into their lives, offers the following suggestions for bone building:

• Incorporate balance work such as yoga at the beginning of a workout to help prevent falls.

• Women should use weight-lifting machines in the gym, beginning with lower weights (the amount a woman can push or pull for 15 repetitions, with the last one being a challenge) and gradually increasing both weight and repetitions over time.

• In the absence of joint or muscular problems, Detroyer recommends jumping activities such as jumping rope, jumping up on a bench, and simply jumping up and down on the floor. The impact helps build bone.

• To help the spine, include exercise that strengthens the back muscles, such as back extensions, bridges, and planks.

• To avoid injury, people should work with an exercise physiologist or a personal trainer with a degree and certification to work with specialized population

Medication
Like all medications, drugs designed to maintain or improve bone density, such as Fosamax, Boniva, Actonel, and Reclast, carry potential side effects, including heartburn, ulcers, weakened jawbones, and, ironically, an increased risk of certain types of fractures. There is no consensus as to who might benefit the most from these drugs (ie, when the benefits outweigh any potential risks). Currently, physicians and patients make these determinations on an individual basis.

Final Thoughts
Detroyer emphasizes that individualization is key when it comes to treating low bone mass. As an example, she cites a client who had seen several physicians and was repeatedly diagnosed with low bone mass. She was prescribed medications, supplements, and exercise training. Unconvinced that the problem was solved, she underwent testing for gluten intolerance, which came back positive. None of the recommendations for treating low bone mass would have helped without first dealing with the underlying gluten intolerance.

If, however, there is no obvious underlying condition, the three-pronged approach of diet, exercise, and medications is the key to preventing further bone loss and even increasing bone mass.

— Densie Webb, PhD, RD, is a freelance writer, editor, and industry consultant based in Austin, Tex.

 

References
1. U.S. Preventive Services Task Force. Screening for osteoporosis: U.S. Preventive Services Task Force Recommendation statement. Ann Intern Med. 2011;154(5):356-364.

2. Institute of Medicine Food and Nutrition Board. Dietary Reference Intakes for Calcium and Vitamin D. Washington, D.C.: National Academies Press; 2010.

3. Chubak J, Ulrich CM, Tworoger SS, et al. Effect of exercise on bone mineral density and lean mass in postmenopausal women. Med Sci Sports Exerc. 2006;38(7):1236-1244.

4. Papaioannou A, Morin S, Cheung AM, et al. 2010 clinical practice guidelines for the diagnosis and management of osteoporosis in Canada: Summary. CMAJ. 2010;182(17):1864-1873.

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