This is a thorough and balanced report of research into the effects of yoga on bone density. While yoga provides a range of potential health benefits including increased flexibility, balance and strength (all factors which can help prevent falls and fractures), the researchers focused specifically on whether a 12 minute per day yoga routine could increase bone density. Although improvements were found after a decade of research, helpful caveats about the limitations of the study (lack of a control group, self-reported nature of the study) kept it away from the realm of exaggeration.
Yoga is hugely popular and growing in importance, so understanding the specific effects of daily practice of yoga could influence current thinking about its role in disease prevention and health promotion. If a specific effect of yoga on bone density is likely then possibly reducing fracture risk through daily yoga practice could be a viable alternative to ingesting bisphosphonate drugs. As the article mentions, these drugs are widely prescribed for osteoporosis and are frequently toxic to the gastrointestinal system as well as having other numerous serious adverse effects.
While the article did not specifically state how much it costs to do a 12 minute yoga session everyday, one can assume it is relatively inexpensive and cost is not really an issue here. Where it becomes an issue is when yoga practitioners attend expensive classes, feel compelled to buy expensive yoga accessories, travel to India to spend time with yoga gurus, and generally spend lots of personal time practicing it, all which could lead to considerable costs.
The story notes, “The findings, as reported last month in Topics of Geriatric Rehabilitation, showed improved bone density in the spine and femur of the 227 participants who were moderately or fully compliant with the assigned yoga exercises.” [emphasis ours] What exactly does that mean? How much did bone density improve? Did all 227 subjects see improvement or was the improvement seen in aggregate? There is a big difference between the two and the common take away would be that all saw improvements, which is far from the reality. We also would like to know why only 227 out of 741 original enrollees are reported on. How many of the remaining 500+ participants dropped out? Research study dropout is an important factor as it gives us some idea of the tolerability or acceptability of the ‘treatment.’
The story provides insight into the downsides of bisphosphonate therapy but says nothing about the potential dangers of yoga. It is true that, done correctly, yoga is not likely to produce significant injuries. However, the subjects in the study were not supervised nor was their positioning for each of the poses determined. Incorrect alignment can cause joint strain and joint and injury. In fact, the Times itself has previously reported that yoga can wreck your body!
Appropriate caveats about the lack of control group and the fact the study was among self-selected volunteers (perhaps a hint of ‘healthy-people bias’) were helpful. Other limitations of the research, such as the dependence on self-reporting of the participants’ daily yoga practice (people often either forget or give socially appropriate responses in surveys) could have been discussed.
No evident disease mongering in this story, except to say that osteoporosis and it’s precursor osteopenia are often heavily mongered diseases simply because bone density is one of many risk factors for hip fractures (that is treatable with drugs) but it is not the most important one. In fact, some argue that bone density is such a low predictor for hip fractures it is worthless as a measure of bone health and simply shouldn’t be employed.
Dr. Fishman invested a ‘significant chunk’ of his own money into the research and we appreciate that the story put that financial interest out in the open. Apart from the selling of the DVDs used, it hard to imagine how there could be a significant financial gain from the study. However, given that investment, it wold have been valuable to have comments from others in the field speaking to the study results and the basic premise entailed. This kind of research might be more influenced by more subtle intellectual conflicts of interest, where the researchers are intellectually identified with an idea (yoga=good) and would have difficulty accepting alternative hypotheses. The lack of a control group becomes somewhat problematic as it is possible that a similar group of non-yoga performing people would also see increases in their bone density.
The article mentions the tolerability of osteoporosis drugs, though the study wasn’t a comparison between the two. While the study didn’t examine this, comparing yoga’s effects against alternative weight-bearing exercise forms (running, walking) might merit a mention.
Yoga is everywhere (the phrase ’12 important yoga poses’ gives 6.2 million hits on google).
The report doesn’t make any claims for novelty where none exists. The overall benefits of yoga are fairly well-established, even if those benefits may not be strictly ‘evidence-based’. What is ‘new’ is the research trying to demonstrate effects of yoga on a single parameter (bone density) and we think the researchers should be lauded for trying to apply some rigor to answering these kinds of specific questions.
There is no evidence of reliance on a news release