AHA Scientific Statement cautiously suggests that meditation may help CV risk reduction
Meditation and Cardiovascular Risk Reduction
A Scientific Statement From the American Heart Association
Based on a systematic review of data on the potential benefits of meditation on cardiovascular (CV) risk, the American Heart Association (AHA) concludes that the studies suggest a possible benefit of meditation, although the overall quality, and in some cases quantity, of study data are modest. Given the low costs and low risks of meditation, it may be considered as an adjunct to guideline-directed CV risk reduction by those interested in this lifestyle modification.
CV disease remains a leading cause of morbidity and mortality, despite advances in the prevention and treatment of atherosclerosis. Novel and inexpensive interventions that can contribute to primary and secondary prevention of CV disease are of interest. Multiple studies have reported benefits of meditation, so the AHA committee aimed to examine whether this wide accessible and inexpensive activity may represent an attractive cost-effective adjunct to more traditional medical therapies.
The systematic and scientific review was restricted to practices of sitting meditation, thereby excluding practices such as tai chi, qigong and yoga, which also involve physical activity.
The Scientific Statement considered the effects of meditation on the brain, in particular long-term neurophysiological and neuroanatomical changes. Studies suggest that meditation can indeed have long-standing effects on the brain, which may have beneficial consequences on the physiological basal state, physiological responses and CV risk. It should be noted though, that the majority of the studies were small and non-randomized, sometimes involving highly experienced meditators. It was also noted that each form of meditation (eg focused attention, mindfulness and loving kindness) will have different psychological and neurological effects, thus effects of one type cannot be extrapolated to another.
The Statement studied data on effects of meditation on CV risk factors such as blood pressure, smoking and tobacco use, responses to stress, insulin resistance and metabolic syndrome, and on CV pathogenic processes such as subclinical atherosclerosis, endothelial function and inducible myocardial ischemia. Summaries of all relevant studies are provided in clear tables, which list the primary findings and comments on the methodology.
Based on all studies considered, the authors conclude that studies of meditation to date suggest a possible, but not definitely established, benefit of meditation on CV risk reduction. The quality of the studies in this field has improved over time, but methodological issues remain. As with many other novel interventions, it is possible that publication bias towards positive studies exists. Moreover, investigators may be strong believers or enthusiast meditators themselves, thereby introduction potential unintended bias. Many of the studies are conducted by the same group of researchers, thus independent verification of reported positive findings is warranted.
The Statement concludes that the benefits of such intervention remain to be better established, where possible using randomized study designs, and ensuring adequate power, stimulating lower drop-out rates, and with longer follow-up and unbiased analysis.