Many medical and independent studies have touted the health benefits of prayer, meditation and other religious activities, but recent research suggests these findings may be flawed.
Studies on meditation continually claim that the practice has positive effects on reducing stress, tension, anxiety and panic, as well as lowering high blood pressure and relieving chronic pain. Many people use the calming mental exercises to help with headaches and respiratory problems like asthma. Others use it as an enhancement to cancer treatments. Overall, the practice seeks to alleviate factors that can aggravate a variety of medical conditions. Peter H. Canter, research fellow in complementary medicine at Peninsula Medical School in Exeter, England, claims that research on the direct link of meditation and health is fraught with methodological problems. In many cases, the studies are not randomized; researchers select favorably predisposed subjects whose expectations of benefits exceed those of control subjects. In his article, "The therapeutic effects of meditation," published in the British Medical Journal, Canter said that trials of transcendental meditation, when controlled at all, often compare participants who volunteered to be meditators with non-meditators, or long-term meditators with novices. These trials did not check for differences between people who choose to learn meditation techniques and those who do not, or between people who persist with the practice and those who abandon it. In some cases, the research was conducted by people directly involved in organizations keen on proving the unique value of meditation, particularly transcendental meditation, which involves the mental repetition of a mantra. Subjects often partake in a variety of unrelated practices that create uncontrolled variables, making it difficult to attribute health benefits specifically to meditation. The use of multiple cointerventions, high attrition and inadequate statistical analysis has weakened the findings, said Canter. For example, if an experimental group receives meditation training and an altered diet while the control group receives nothing or sham meditation, and a positive change is observed in the experimental group, it is impossible to attribute the change to meditation or to diet or to the combination - the separate effects of the two treatments are obscured.
According to Canter, though, the overall evidence for the therapeutic effectiveness of any type of meditation is weak, and evidence for any specific effect above that of credible control interventions even more so. He said he does believe, however, that future trials with improved design may yet provide more concrete results linking health and meditation practices.