Tuesday May 17 2011
The health benefits of t'ai chi are still unclear
“Elderly people should take up the gentle martial art of T’ai Chi for the sake of their physical and mental health,” said The Daily Telegraph.
The news is based on a study that examined a spectrum of potential health benefits of t’ai chi, the ultra slow martial art that is reputed to improve both body and mind. The research pulled together 35 systematic reviews, a type of study that combines multiple studies to examine an issue. These individual reviews each looked at benefits of t’ai chi for various conditions, including preventing osteoporosis and preventing falls.
The researchers say their study provides relatively clear evidence that t’ai chi can prevent falls and improve psychological wellbeing, although it was found to be of little benefit in treating the symptoms of cancer and rheumatoid arthritis. Due to variable data across the studies no overall conclusions were drawn on whether t’ai chi was beneficial in reducing cardiovascular diseases or its risk factors,
This study has highlighted that further research is still needed to understand many of the potential health benefits of t’ai chi. There should also be further high-quality primary research, particularly as some reviews examined suffered from poor quality data.
Where did the story come from?
The study was carried out by researchers from the Korea Institute of Oriental Medicine in Daejeon, South Korea and the University of Exeter. It was funded by The Korea Institute of Oriental Medicine.
The study was published in the peer-reviewed British Journal of Sports Medicine. The research was covered appropriately by The Daily Telegraph.
What kind of research was this?
Several systematic reviews have assessed the effectiveness of t’ai chi for fall prevention and conditions such as high blood pressure. However, the results of these past systematic reviews have not been consistent.
This was a systematic review and critical appraisal of all previous systematic reviews that had assessed t’ai chi. It aimed to see if there were differences in the quality of these reviews that may be responsible for the variation seen.
Systematic reviews are the best way to see whether an intervention works or not. This is because they pool all available data to make an assessment. There are also standard procedures that systematic reviews follow to assess how much each included study influences the whole result. For example, a large, well-performed study would give a better idea of how effective a treatment was compared to a smaller study of lesser quality.
What did the research involve?
The researchers searched international medical and scientific databases, including those from Korea and China, for systematic reviews and meta analyses that had assessed t’ai chi for any condition.
Two researchers looked at the abstracts (the summary sections) of all of the identified journal articles and decided whether they did indeed fulfil systematic review criteria. These criteria stated that:
- reviews had to include an explicit, repeatable methods section that described how the researchers had searched for papers for inclusion
- reviews had to describe clearly which people were eligible to be included and which were not
- reviews had to specifically address the effectiveness of t’ai chi and include evidence from at least two controlled clinical trials
The researchers excluded any systematic reviews that evaluated t’ai chi in combination with other treatments without separately evaluating the individual approaches.
The pooled reviews were each assessed using the Overview Quality Assessment Questionnaire. This questionnaire assessed how well each systematic review was performed, assigning them with total scores from one to seven. A score of three or less indicates extensive or major flaws, a score of five or more suggests only minor or minimal flaws.
What were the basic results?
The researchers found that 35 systematic reviews met their inclusion criteria. These reviews had been published between 2001 and 2010. Ten of these studies had incorporated a meta-analytic approach (they had pooled data from several studies into a large statistical analysis) and the reviews were each based on between 2 and 47 primary studies.
The systematic reviews had looked at t’ai chi for cancer, general healthcare in older people, Parkinson’s disease, musculoskeletal pain, arthritis, muscle strength and flexibility, improving aerobic capacity, cardiovascular disease and its risk factors, lowering blood pressure, osteoporosis and bone mineral density, type 2 diabetes, fall prevention and improving balance, psychological health and other chronic conditions.
They found that 17 of the systematic reviews had minimal bias, 11 had major flaws and seven had moderate flaws. Nine systematic reviews were considered high quality. Of these, one systematic review found that t’ai chi had a beneficial effect; five found no effect for t’ai chi and three systematic reviews drew no conclusion.
Across all of the systematic reviews a relatively clear consensus existed that t’ai chi was effective for improving the general health of older people, improving psychological health and for preventing falls. Of the four systematic reviews that evaluated fall prevention, three showed clearly positive effects of t’ai chi, whereas one cast doubt on the effectiveness of t’ai chi.
Five systematic reviews had evaluated psychological health, with four suggesting that t’ai chi had a benefit, whereas one did not reach firm conclusions. All three systematic reviews that had evaluated healthcare in older people found that t’ai chi had a positive effect.
T’ai chi for rheumatoid arthritis and cancer were each looked at by two reviews. These found no evidence that t’ai chi was beneficial for treating the symptoms of either of these conditions.
There were contradictions in the systematic reviews that had looked at t’ai chi for cardiovascular disease. They found the systematic reviews that had found a positive effect tended to be of poorer quality, having including data from trials that were not randomised controlled trials. The positive systematic reviews also tended to include a higher proportion of trials from China, the researchers note.
The researchers said that the systematic reviews related to Parkinson’s disease and type 2 diabetes were based on relatively small numbers of primary studies, and conclude that their findings may be less reliable. They suggest that more high-quality studies are needed to assess whether t’ai chi had a positive effect in these two conditions.
How did the researchers interpret the results?
The researchers say that as a form of complementary therapy t’ai chi has been used in the treatment of various conditions and ‘has been reported as beneficial for reducing blood pressure and knee pain, improving balance and muscle strength, and improving fall prevention’.
They say their study had shown that there have been numerous systematic reviews, often with contradictory conclusions. However, the evidence is only convincingly positive for fall prevention and psychological health improvement.
They recommend ‘t’ai chi for older people for its various physical and psychological benefits. However, t’ai chi may not effectively treat inflammatory diseases and cardio-respiratory conditions’.
This review of systematic reviews showed that there is great interest in the potential health benefits of t’ai chi, with 35 systematic reviews published on the topic.
The researchers found that the systematic reviews were of variable quality, with some being small some including poorer quality studies (for example, studies other than randomised controlled trials). This makes the findings of these less reliable.
They found that the results for the systematic reviews that had looked at t’ai chi for preventing fall falls were largely consistent and showed a positive effect for t’ai chi in these instances. As these were higher quality reviews, the results here can be trusted to guide practice.
When looking at improving psychological health the methodological quality of the underlying trials was variable, but the direction of the effect was clear - four of five studies showing an improvement, with one further study being neither positive nor negative. This result based on up to 47 single randomised trials seems reliable.
Whether there are benefits for t’ai chi in preventing cardiovascular disease or improving its risk factors is less certain. The results are less consistent (contradictory) or come from poorer quality trials, making conclusions from this data less reliable.
Common weaknesses in the underlying studies included the small size of the sample population and the lack of a control group. This means the overall conclusions made in these particular systematic reviews are not as certain or final.
This review also provided a description of the published studies but further work is needed to quantitatively assess whether t’ai chi is beneficial for each of the conditions. The researchers suggest that some of the systematic reviews had included poorer quality primary studies; therefore further research on t’ai chi should be carried out more rigourously using the standardised reporting criteria used for the reporting of clinical trials of drugs.
Although this study suggested that t’ai chi is beneficial for preventing falls and improving psychological health, these should be taken as tentative conclusions because only nine of the 35 studies were found to be of high quality. In addition to further primary studies being conducted, there is potentially a need for further systematic reviews that appraise only high quality primary studies before we can confirm the potentially beneficial effects of t’ai chi.