Yoga may be as effective as traditional exercise for reducing cardiovascular risk factors, researchers say.
Yoga has roots as an ancient mind-body practice that incorporates physical, mental and spiritual elements. Originating in India, yoga has been proven effective in numerous studies to improve cardiovascular risk factors, with a reduction in the risk of heart attacks and strokes.
Investigators from the US and Netherlands conducted a systematic review of 37 randomized controlled trials, which included 2,768 subjects. The aim of the analysis was to examine whether yoga is beneficial in managing and improving cardiovascular disease risk factors and whether it could be an effective therapy for cardiovascular health.
The researchers comment that the meta-analysis was performed to appraise the ongoing evidence and provide a realistic pooled estimate of yoga's effectiveness when measured against exercise and no exercise.
Results showed that risk factors for cardiovascular disease improved more in those practicing yoga than in those individuals not taking part in exercise. Yoga had an effect on risks factors comparable to exercise.
When compared with no exercise, yoga was associated with significant improvement in each of the primary outcome risk factors measured:
Yoga has become popular as a form of physical exercise based upon asanas (physical poses) to promote bodily or mental control and well-being.
- Body mass index (BMI) reduced by 0.77 kg/m2 (measured as a "mean difference")
- Systolic blood pressure reduced by 5.21 mm Hg
- Low-density (bad) lipoprotein cholesterol reduced by 12.14 mg/dl
- High-density (good) lipoprotein cholesterol increased by 3.20 mg/dl.
Significant changes were also observed in secondary endpoints:
- Body weight decreased by 2.32 kg
- Diastolic blood pressure reduced by 4.9 mm Hg
- Total cholesterol reduced by 18.48 mg/dl
- Heart rate dropped by 5.27 beats/min.
No improvements were found in parameters of diabetes (fasting blood glucose and glycosylated hemoglobin).
Cardiovascular disease risk factor improvements in BMI, blood pressure and lipid levels were substantial when yoga was practiced in addition to medication. Meanwhile, in patients with existing coronary heart disease, yoga displayed a statistically significant benefit in lowering LDL cholesterol when added to statins and lipid-lowering drugs.
Individuals unable to perform aerobic exercise can still achieve cardiovascular benefits
Following the review of trials, researchers found that yoga may provide the same benefits in risk factor reduction as exercise such as brisk walking or biking.
"This finding is significant, as individuals who cannot or prefer not to perform traditional aerobic exercise might still achieve similar benefits in [cardiovascular] risk reduction," the authors say.
Evidence indicates yoga has comparable effects on risks factors as aerobic exercise. However, the researchers note that this could potentially be due to yoga's impact on stress reduction, "leading to positive impacts on neuroendocrine status, metabolic and cardio-vagal function."
"The similarity of yoga and exercise's effect on cardiovascular risk factors suggest that there could be comparable working mechanisms, with some possible physiological aerobic benefits occurring with yoga practice, and some stress-reducing relaxation effect occurring with aerobic exercise," say the investigators.
Senior author Prof. Myriam Hunink, from Erasmus University Medical Center in the Netherlands and Harvard School of Public Health in Boston, MA, says:
"Although the evidence of yoga's beneficial effect in cardiovascular health is growing, a physiological explanation for this effect remains unclear. Also unclear, are the dose-response relationship and the relative costs and benefits of yoga when compared to exercise or medication. However, these results indicate that yoga is potentially very useful and in my view worth pursuing as a risk improvement practice."
The authors of the research document that evidence supports yoga's acceptability to patients with pre-existing cardiac conditions, lower physical tolerance, the elderly or those with musculoskeletal or joint pain.
"Yoga has the potential to be a cost-effective treatment and prevention strategy given its low cost, lack of expensive equipment or technology, potential greater adherence and health-related quality of life improvements, and possible accessibility to larger segments of the population," the authors conclude.