Altered Brain Metabolism is Associated with Long-Term Yoga Practice
By John M. de Castro, Ph.D.
“the benefits of yoga are more encompassing than just the physical. And, thanks to modern technology and functional MRI scans, we’re now able to see how regular practice affects your brain.” – Emmy Lymn
The practice of yoga has many benefits for the individual’s physical and psychological health. Yoga has diverse effects because it is itself diverse having components of exercise, mindfulness meditation, and spirituality. So, yoga nourishes the body, mind, and spirit. As a result, yoga practice would be expected to produce physical changes. These include the relaxation response and stress relief. These should be obvious in the muscles, tendons and joints, but, less obvious in the nervous system. The nervous system changes in response to how it is used and how it is stimulated in a process called neuroplasticity. Highly used areas grow in size, metabolism, and connectivity. Mindfulness practices in general are known to produce these kinds of changes in the structure and activity of the brain.
In today’s Research News article “Long-term Ashtanga yoga practice decreases medial temporal and brainstem glucose metabolism in relation to years of experience.” (See summary below or view the full text of the study at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7225240/), Aalst and colleagues recruited experienced adult yoga practitioners (at least 2 years of 3 times per week practice) and non-practitioners matched for age, gender, education, and physical activity levels. They had the experienced yoga practitioners perform 75 minutes of yoga while the control group practiced 75 minutes of aerobic exercise. Before and after they underwent a Positron Emission Tomography (PET) brain scan to determine changes in glucose metabolism (metabolic activity) in various brain regions.
They found that the experienced yoga practitioners at rest had significantly lower levels of activity in the hippocampus, parahippocampus, amygdala, insula, anterior midbrain, striatum (globus pallidus), and cerebellum compared to non-practitioners. After yoga practice there was a significant increase in activity in the cerebellum that wasn’t present for the non-practitioners after aerobic exercise. No significant differences in grey matter volume was observed.
The findings that the activity (brain metabolism) in the yoga practitioners while at rest is altered suggests that these are relatively permanent neuroplastic changes in the brain produced by long-term yoga practice. These changes are in areas that are known to be involved in mood and emotion regulation (limbic system, hippocampus, parahippocampus, amygdala), motor movements (cerebellum and striatum), and interoception and body awareness (Insula). These results are in line with the established ability of yoga practice to improve mood and emotion regulation, interoception and body awareness, and movement.
The findings are correlational and as such causation cannot be determined. But prior research has established that yoga training produces similar improvements in well-being and changes in the brain suggesting that these effects are caused by yoga practice. Yoga practice is a complex set of activities including postures, meditation, breathing practice, spirituality, and relaxation. It will remain for future research to determine which of these components or which combinations are responsible for which effects.
Yoga practitioners have different levels of brain activity at rest reflecting the psychological changes observed in yoga practitioners. The psychological changes suggest that the better emotional and physical well-being in yoga practitioners is due to neuroplastic changes in the brain produced by long-term yoga practice. These results support the recommendation of practicing yoga to improve physical and psychological well-being.
So, altered brain metabolism is associated with long-term yoga practice.
“The practice of yoga helps improve emotional regulation to reduce stress, anxiety and depression and that seems to improve brain functioning.” – Neha Gothe
CMCS – Center for Mindfulness and Contemplative Studies
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van Aalst, J., Ceccarini, J., Schramm, G., Van Weehaeghe, D., Rezaei, A., Demyttenaere, K., Sunaert, S., & Van Laere, K. (2020). Long-term Ashtanga yoga practice decreases medial temporal and brainstem glucose metabolism in relation to years of experience. EJNMMI research, 10(1), 50. https://doi.org/10.1186/s13550-020-00636-y
Yoga is increasingly popular worldwide with several physical and mental benefits, but the underlying neurobiology remains unclear. Whereas many studies have focused on pure meditational aspects, the triad of yoga includes meditation, postures, and breathing. We conducted a cross-sectional study comparing experienced yoga practitioners to yoga-naive healthy subjects using a multiparametric 2 × 2 design with simultaneous positron emission tomography/magnetic resonance (PET/MR) imaging.
18F-FDG PET, morphometric and diffusion tensor imaging, resting state fMRI, and MR spectroscopy were acquired in 10 experienced (4.8 ± 2.3 years of regular yoga experience) yoga practitioners and 15 matched controls in rest and after a single practice (yoga practice and physical exercise, respectively).
In rest, decreased regional glucose metabolism in the medial temporal cortex, striatum, and brainstem was observed in yoga practitioners compared to controls (p < 0.0001), with a significant inverse correlation of resting parahippocampal and brainstem metabolism with years of regular yoga practice (ρ < − 0.63, p < 0.05). A single yoga practice resulted in significant hypermetabolism in the cerebellum (p < 0.0001). None of the MR measures differed, both at rest and after intervention.
Experienced yoga practitioners show regional long-term decreases in glucose metabolism related to years of practice. To elucidate a potential causality, a prospective longitudinal study in yoga-naive individuals is warranted.