Exercise Trumps Ad Claims

Q:  I am a healthy, active 76-year-old female with bone density testing that shows osteopenia (a mild reduction in bone density). Some friends and I are interested in learning more about ads we have seen for a machine that claims it improves bone density. Basically, it consists of a vibrating platform to do your exercises on.

I sent for material to explain how the platform works, but the material doesn't seem to support its claims. Will using the platform increase my bone density as the ad states, or is it too good to be true?

A:  The ads you mention claim that 10 minutes of daily vibration therapy will help to improve bone density. It cites one study and references the website of the US Surgeon General on treatments for osteoporosis as support for its claim of improving bone health.

The study cited in the ad (Rubin 2004 et al) was a small study done in healthy postmenopausal women. In the study, the women were to use the vibrating platform for 10 minutes twice a day at 0.2gs (this is important, because the vibration studies all seem to use different time limits and frequencies). Using complicated statistical analysis, they did show a very slight benefit in people who used the vibrating platform compared to those who did not.

The Surgeon General's website states that "for those who cannot engage in regular physical activity due to disability, mechanical stimulation of the skeleton might prove beneficial." It goes on to state, however, that "the long-term safety and efficacy of such approaches remains to be determined and therefore exercise programs aimed at increasing activity remain critical" in protecting from osteoporosis.

Part of the concern about vibration therapy is its safety. We know that workers exposed to chronic vibration stimulation, such as through jackhammers, can actually cause harm. Furthermore, the studies done for vibration therapy were completed in healthy subjects, not elderly patients with frail bones or disorders such as diabetes and heart disease. Additionally, the studies use multiple different frequencies and duration of vibration and therefore, the best amount of vibration has yet to be determined.

In contrast to vibration therapy, which only has only small studies to support its claims, exercise has numerous large-scale studies that show it improves bone density. Furthermore, the effects of exercise extend far beyond just bone health; it improves cardiovascular health, reduces blood pressure, and improves overall well-being through natural endorphins. Another benefit: most exercises needed to improve bone health are free, including activities such as walking, dancing, running, or biking. The machine you mentioned costs about $500.

So, while there is a small amount of data that supports vibration therapy to prevent osteoporosis, I recommend going with good old weight-bearing exercise for 30 minutes on most days of the week. It's less expensive and there is more research to support its safety and beneficial effects.

In addition to talking to your doctor about starting your exercise program, remember to discuss the appropriate amounts of calcium and vitamin D to help prevent your bone density worsening from osteopenia to overt osteoporosis.

I would like to thank Dr. Irina Konon, Medical College of Wisconsin rheumatologist, for reviewing this column.

Deidre L. Faust, MD, is a Staff Physician (Internal Medicine) at the Medical College of Wisconsin's Plank Road Clinic. Her column appears in the Milwaukee Journal-Sentinel.